Multifunctional anabaena-bacterium composite growth-promoting organic fertilizer and preparation method thereof

Abstract

The invention provides a multifunctional anabaena-bacterium compound growth-promoting organic fertilizer and a preparation method thereof. The organic fertilizer is prepared from the following raw materials in parts by weight: 60 to 80 parts of cow dung, 15 to 25 parts of modified porous attapulgite carrier, 0.5 to 1.5 parts of bacillus, 15 to 25 parts of anabaena powder, 8 to 12 parts of actinomycetes powder and 1 to 3 parts of trichoderma powder. According to the multifunctional anabaena-bacterium composite growth-promoting organic fertilizer disclosed by the invention, a continuous and synchronous fermentation process is carried out by adopting the modified porous attapulgite carrier loaded anabaena and beneficial bacteria, so that the biological function expression efficiency and the rhizosphere microorganism ecological regulation capability of the organic fertilizer are remarkably enhanced; the soil conditioner achieves an expected improvement effect in the aspects of soil reconstruction and agricultural green synergism, and can be widely applied to the fields of farmland soil pollution, soil quality improvement, atmospheric carbon and nitrogen fixation, crop yield increase and quality improvement and the like.

Description

Technical Field

[0001] The invention belongs to the field of agriculture, and in particular relates to a multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer and a preparation method thereof. Background Art

[0002] With the continuous development of agricultural production, the excessive use of chemical fertilizers and agricultural pollution are becoming increasingly serious. The large-scale use of chemical fertilizers, pesticides and other chemical substances not only leads to a decline in soil quality and aggravated soil pollution, but also has negative impacts on the environment and ecosystems, such as eutrophication of water bodies and increased greenhouse gas emissions. Existing organic fertilizers have certain advantages in improving soil quality, providing nutrition and promoting crop growth, but most of them focus on a single function, such as increasing soil organic matter and providing basic nutrients. In actual application, farmland soil faces multiple challenges, including heavy metal pollution, pests and diseases, soil nutrient imbalance, and reduced biodiversity. Single-function organic fertilizers are difficult to cope with the multiple environmental challenges facing modern agriculture. In order to achieve sustainable development of agricultural production, there is an urgent need for a multifunctional compound organic fertilizer that can repair soil pollution, improve soil quality, increase crop yield and quality, while also enhancing agricultural carbon sequestration and sink capacity, and helping to reduce greenhouse gas emissions.

[0003] Anabaena efficiently fixes carbon dioxide through photosynthesis, increasing soil organic matter and secreting beneficial plant hormones that enhance crop disease and pest resistance, making it an excellent carbon capture and bioremediation material. Beneficial bacteria improve the soil microecology, promote nutrient cycling, and enhance plant root activity, thereby enhancing crop health and yield. However, the interaction between Anabaena and beneficial bacteria is complex. Due to changes in environmental factors (such as temperature, pH, and nutrient concentration), the interaction between Anabaena and beneficial bacteria is easily inhibited or interfered with, resulting in an extremely unstable synergistic effect and difficulty in long-term coexistence.

[0004] Therefore, how to develop a compound organic fertilizer in which Anabaena and beneficial bacteria can coexist for a long time and synergistically promote crop growth, and thus achieve comprehensive compound organic fertilizers with multiple functions such as repairing soil pollution, improving soil quality, increasing crop yields and improving quality, and preventing and controlling crop diseases and pests, is a key technical problem that technicians in this field urgently need to overcome. Summary of the Invention

[0005] In view of this, the present invention aims to overcome the defects in the prior art and proposes a multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer and a preparation method thereof.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] The present invention provides a multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer, which comprises the following raw materials in parts by weight:

[0008] 60-80 parts of cow dung, 15-25 parts of modified porous attapulgite carrier, 0.5-1.5 parts of Bacillus, 15-25 parts of Anabaena powder, 8-12 parts of actinomycete powder, and 1-3 parts of Trichoderma powder.

[0009] Furthermore, the modified porous attapulgite carrier is prepared by a method comprising the following steps:

[0010] (1) mixing attapulgite powder and chicken manure uniformly, performing a carbonization reaction under a nitrogen atmosphere, and grinding to obtain high-temperature carbonized attapulgite after the reaction is completed;

[0011] (2) dispersing the high-temperature carbonized attapulgite into a buffer solution, adding caffeic acid ethylamine thereto, and obtaining a PCEA film after the reaction is completed;

[0012] (3) centrifuging, washing, and drying the PCEA film to obtain a polycaffeic acid amine-coated carbonized attapulgite material;

[0013] (4) The polycaffeic acid amine-coated carbonized attapulgite material is dispersed in deionized water, and a rhamnose polysaccharide solution is added thereto. After the reaction is completed, the modified porous attapulgite carrier is obtained after washing and drying.

[0014] Furthermore, the mass ratio of attapulgite powder to chicken manure in step 1 is 1-8:1-2; the temperature of the carbonization reaction in step 1 is 450-550° C., and the time is 1.5-2.5 hours.

[0015] Furthermore, the buffer in step 2 is Tris-HCl, the pH value of the buffer is 8.5, and the concentration of the buffer is 10-40 mM; the mass ratio of the high-temperature carbonized attapulgite to caffeic acid ethylamine in step 2 is 10:1-3; the temperature of the reaction step in step 2 is 20-30°C, and the time is 6-18 hours.

[0016] Furthermore, the solid-liquid ratio of the polycaffeic acid amine-coated carbonized attapulgite material to deionized water and rhamnose polysaccharide solution in step 4 is 1 g:9-14 mL:1-6 mL; the mass concentration of the rhamnose polysaccharide solution in step 4 is 0.05-0.15%; and the reaction time in step 4 is 4-8 hours.

[0017] Furthermore, the Bacillus comprises Bacillus subtilis and Bacillus amyloliquefaciens in a mass ratio of 1-2:1-2; and the Anabaena powder comprises Spirulina platensis and Anabaena azotica in a mass ratio of 1-3:1.

[0018] Furthermore, the actinomycete powder comprises Streptomyces graminofaciens, Streptomyces limosus and Streptomyces albidoflavus in a mass ratio of 1-4:1:0.5-2; the Trichoderma powder comprises Trichoderma harzianum and Trichoderma longibrachiatum in a mass ratio of 1-2:1-2.

[0019] The present invention also provides a method for preparing a multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer, comprising the following steps:

[0020] The modified porous attapulgite carrier is evenly mixed with cow dung and Bacillus powder, and compost fermentation is carried out. After the fermentation is completed, the temperature is reduced to 20-35° C., and Anabaena powder, actinomycete powder, Trichoderma powder and sterile water are added thereto. After evenly mixing, secondary fermentation is carried out to obtain the multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer.

[0021] Furthermore, the composting and fermentation step specifically includes turning the compost every 2-3 days, maintaining a compost temperature of 45-50°C, a humidity of 55-65%, and a pH of 6-7. The amount of sterile water added is 3-5 times the combined mass of the Anabaena powder, actinomycete powder, and Trichoderma powder. The sterile water is purified by filtration, reverse osmosis, and other methods, followed by high-temperature sterilization to completely kill all microorganisms in the water.

[0022] Furthermore, the secondary fermentation step is specifically as follows: turning the compost every day, the fermentation humidity is 55-65%, the fermentation time is 7-15 days, artificial white light is added, the light intensity is 3000-5000 lux, and the lighting time is 10-14 hours / day.

[0023] The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer of the present invention breaks through the ratio mode of traditional organic fertilizers. It adopts a combination of high-content Anabaena powder and actinomycete powder (15-25 parts: 8-12 parts) and a combination of low-content Bacillus and Trichoderma (0.5-1.5 parts: 1-3 parts) to construct a microbial system, forming a unique nonlinear synergistic mechanism: (1) the extracellular polysaccharides and soluble organic nitrogen produced by the metabolism of Anabaena effectively promote the growth of Bacillus, while increasing the activity of its growth-promoting and disease-preventing enzymes such as proteolytic enzymes and chitinase, so that it can still play a strong growth-promoting role under low-dose conditions; the various hydrolytic enzymes secreted by Bacillus further accelerate the decomposition of organic matter in Anabaena, improve the release efficiency of soil nutrients, and form a virtuous growth-promoting cycle of "algae promoting bacteria, bacteria decomposing algae". (2) The nitrogen fixation ability of Anabaena is enhanced under the specified ratio conditions of the present invention, significantly improving the efficiency of soil nitrogen supply, and synergistically promoting the decomposition of organic matter and nitrogen circulation with actinomycetes, maintaining the dynamic balance of soil nitrogen supply; the antibacterial metabolites of actinomycetes selectively inhibit soil harmful bacteria, have no inhibitory effect on Bacillus, and instead induce it to release more volatile organic compounds, further promoting the growth of crop roots and enhancing crop stress resistance. (3) Using high-temperature carbonized attapulgite as the skeleton material, polycaffeic acid ethylamine and rhamnose polysaccharide (RG-II) are in situ grafted to form a composite functional layer porous microbial carrier with a multi-level pore structure, directional recognition function and biofilm induction ability, providing a microenvironmental niche for microalgae, actinomycetes and Trichoderma, and inducing the construction of a stable microalgae-bacteria-fungus symbiotic biofilm network structure. Among them, Trichoderma colonizes on the surface of modified porous carbonized attapulgite to form a stable biofilm, and synergizes with various enzymes secreted by microalgae and actinomycetes to accelerate the decomposition and utilization of organic matter, while effectively inhibiting the colonization of harmful bacteria, and building a long-term stable soil disease-resistant ecosystem. In addition, the organic acids produced by the metabolism of Trichoderma further activate the antibacterial metabolic activity of actinomycetes, and the two work together to construct a composite disease-resistant barrier, effectively inhibiting the growth of soil-borne pathogens. Compared with conventional organic fertilizers, the composite growth-promoting organic fertilizer ratio system described in the present invention significantly stimulates soil biological activity, produces outstanding soil remediation and crop growth promotion and disease prevention and control effects, and achieves a nonlinear synergistic effect that far exceeds conventional ratios.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer described in the present invention adopts a modified porous attapulgite carrier to load Anabaena and beneficial bacteria for a continuous synchronous fermentation process, which significantly enhances the biological function expression efficiency of the organic fertilizer and the ecological regulation ability of rhizosphere microorganisms, and achieves improvement effects that exceed expectations in soil reconstruction and agricultural green efficiency improvement. It can be widely used in the fields of farmland soil pollution, soil quality improvement, atmospheric carbon and nitrogen fixation, crop yield increase and quality improvement, etc.

[0026] The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer disclosed herein is based on the growth-promoting activation mechanism of Anabaena's extracellular metabolites, breaking the limitations of the synergistic effects of traditional microbial organic fertilizers. By introducing a combination of Anabaena (15-25 parts) and Bacillus (0.5-1.5 parts) in a specific ratio, a nonlinear synergistic mechanism is formed. The extracellular polysaccharides (especially those rich in mannose and fucose structures) and soluble organic nitrogen secreted by Anabaena metabolism specifically activate the expression of Bacillus' proteolytic enzyme and chitinase genes, enhancing their growth-promoting ability at low doses. Furthermore, the chitinase and polysaccharidase secreted by Bacillus accelerate the degradation and conversion of Anabaena biomass, significantly increasing the mineralization rate of organic matter in the soil and the efficiency of nutrient release available to crops, forming a feedback growth-promoting cycle. This mechanism overcomes the limitation of traditional organic fertilizers, which require high doses of microorganisms to be effective.

[0027] The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer described in the present invention uses the combined action of actinomycetes and Trichoderma to construct a disease-resistant metabolic barrier, thereby enhancing the crop rhizosphere defense system; the streptomycin-type antibacterial substances produced by the metabolism of actinomycetes (such as Streptomyces) show selective inhibitory effects on a variety of pathogenic fungi in the soil; Trichoderma can stably colonize in the porous structure of the modified porous attapulgite carrier, secrete low-molecular organic acids such as malic acid and oxalic acid, activate the secondary metabolic pathway of actinomycetes, and thus increase the release rate of antibiotics; at the same time, the cell wall degrading enzymes secreted by Trichoderma synergistically clear the soil-borne pathogen biofilm and enhance the immune space around the root system; this "actinomycete-Trichoderma" synergistic barrier mechanism effectively improves the systemic resistance and adversity adaptability of crops.

[0028] The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer described in the present invention constructs a composite functional layer microcarrier with biorecognition capabilities, enabling spatial assembly and stable colonization of microorganisms. By high-temperature carbonizing attapulgite, a multi-level pore structure with micropores and above and a porous carbon skeleton with a high specific surface area are constructed. Organic matter is pyrolyzed and reorganized within the attapulgite channels, giving the surface a rich supply of oxygen-containing functional groups such as hydroxyl groups and phenolic hydroxyl groups. This significantly improves the material's hydrophilicity, charge density, and coordination capacity, providing an excellent interfacial environment for subsequent functional layer loading and biofilm stabilization. This structure not only significantly increases the attachment area and colonization site density of microorganisms, but also forms favorable nutrient exchange and gas transmission channels through its multi-level pore network, contributing to the construction of a more stable and functionally diverse microecosystem. Then, polycaffeic acid ethylamine and rhamnose polysaccharide (RG-II) were grafted onto its surface to form a composite functional layer with multi-point recognition and synergistic adsorption functions; the ortho-phenolic hydroxyl group and amino group in polycaffeic acid ethylamine can hydrogen bond with the extracellular polymers of Anabaena, inducing it to secrete an attachment nuclear layer; the rhamnose and galacturonic acid structural fragments in RG-II can undergo molecular recognition with the cell wall polysaccharides of Trichoderma, enhancing its attachment stability and directional growth; the three types of bacteria and algae were adsorbed on the carrier in layers according to their functions, and finally induced the formation of a stable symbiotic biofilm structure, which effectively improved the activity of microorganisms and the ability to continuously promote efficacy.

[0029] The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer of the present invention optimizes bacterial metabolic synergy through a synchronous co-fermentation process, thereby improving product consistency and biological function expression. Different from the traditional step-by-step inoculation and fermentation method, the present invention uses a synchronous fermentation process to enable Anabaena, actinomycetes, Bacillus, and Trichoderma to synergistically metabolize in the same system. The present invention optimizes the initial inoculation ratio and the fermentation environment (pH, ventilation, and temperature) to rapidly establish a complementary symbiotic bacterial community, thereby avoiding functional decline caused by bacterial competition or resistance. The synchronous co-fermentation not only improves the fermentation speed and maturity of the organic fertilizer, but also ensures the stability of the functional expression of each strain, so that the final product has good biological activity and long-lasting effect. DETAILED DESCRIPTION

[0030] Unless otherwise defined, the technical terms used in the following examples have the same meanings as commonly understood by those skilled in the art to which this invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are conventional biochemical reagents; the experimental methods described, unless otherwise specified, are conventional methods.

[0031] The Bacillus subtilis used in each embodiment and each comparative example of the present invention is selected from the China General Microorganism Culture Collection Center, with a deposit number of CGMCC 1.12939;

[0032] The Bacillus amyloliquefaciens used in each embodiment of the present invention and each comparative example is selected from the China General Microbiological Culture Collection Center with a deposit number of CGMCC 1.257; the Spirulina algae used in each embodiment of the present invention and each comparative example is selected from the Algae Seed Bank of the Institute of Hydrobiology, Chinese Academy of Sciences with a deposit number of FACHB-834;

[0033] The blue-green Anabaena used in each embodiment of the present invention and each comparative example is selected from the algae species library of the Institute of Hydrobiology, Chinese Academy of Sciences, with the deposit number FACHB-119;

[0034] The Streptomyces rosinensis used in the examples and comparative examples of the present invention is selected from the U.S. Agricultural Research Service Culture Collection, with the deposit number being NRRL B-2609.

[0035] The Streptomyces citraceus used in each embodiment of the present invention and each comparative example was selected from the ATCC Biological Standard Resource Center in the United States, with a deposit number of ATCC 19778;

[0036] The Streptomyces albus flavus used in each embodiment of the present invention and each comparative example is selected from the China General Microbiological Culture Collection Center, with a deposit number of CGMCC 4.7292;

[0037] The Trichoderma harzianum used in each embodiment of the present invention and each comparative example is selected from the China General Microorganism Culture Collection Center, with a deposit number of CGMCC 5.1242;

[0038] The Trichoderma longibrachiata used in each embodiment of the present invention and each comparative example is selected from the China General Microorganism Culture Collection Center, with a collection number of CGMCC 3.15738.

[0039] The present invention will be described in detail below with reference to the embodiments.

[0040] Example 1

[0041] A method for preparing a multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer comprises the following steps:

[0042] (1) Preparation of modified porous attapulgite carrier: attapulgite powder and chicken manure were mixed evenly in a mass ratio of 8:1, and carbonized for 1.5 hours under a nitrogen atmosphere at 550°C. After the reaction was completed, high-temperature carbonized attapulgite was obtained by grinding; the high-temperature carbonized attapulgite was dispersed in 10 mM Tris-HCl buffer (pH 8.5), and caffeic acid ethylamine was added thereto (the mass ratio of high-temperature carbonized attapulgite to caffeic acid ethylamine was 10:1), and the mixture was reacted at 20°C for 6 hours. The PCEA film should be obtained after completion; the PCEA film is centrifuged, washed, and dried to obtain a polycaffeic acid amine-coated carbonized attapulgite material; the polycaffeic acid amine-coated carbonized attapulgite material is dispersed in deionized water, and 0.05% rhamnose polysaccharide solution is added, and the solid-liquid ratio of the polycaffeic acid amine-coated carbonized attapulgite material to deionized water and rhamnose polysaccharide solution is 1 g:9 mL:1 mL. After reacting for 4 hours, the modified porous attapulgite carrier is obtained after washing and drying.

[0043] (2) Preparation of growth-promoting organic fertilizer: 15 parts of the modified porous attapulgite carrier, 80 parts of cow dung, and 1.5 parts of Bacillus powder (the mass ratio of Bacillus subtilis to Bacillus amyloliquefaciens is 2:1) were mixed evenly, and composting was carried out. The compost was turned over every 3 days. The compost temperature was controlled at 50°C, the humidity was maintained at 65%, and the pH value was maintained at 6. When the temperature dropped to 20°C in the late fermentation stage, 15 parts of Anabaena powder (the mass ratio of Spiral Anabaena to Blue-green Anabaena was 3:1), 12 parts of actinomycete powder (Streptomyces rosinensis) were added. The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer is prepared by mixing 3 parts of Trichoderma powder (3 parts of Trichoderma harzianum and Trichoderma longibrachiatum in a mass ratio of 4:1:0.5), adding sterile water at a rate of 3 times the total mass of the three parts, mixing evenly, and conducting a secondary fermentation. The fermentation humidity is maintained at 55%, and artificial white light is added at the same time, the light intensity is controlled at 3000 lux, the light duration is 10 hours / day, and the compost is turned every day to enhance the oxygen supply. After fermentation for 7 days, the multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer is obtained.

[0044] Example 2

[0045] A method for preparing a multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer comprises the following steps:

[0046] (1) Preparation of modified porous attapulgite carrier: attapulgite powder and chicken manure were mixed uniformly at a mass ratio of 2:1, and carbonized for 2 hours under a nitrogen atmosphere at 500°C. After the reaction was completed, high-temperature carbonized attapulgite was obtained by grinding; the high-temperature carbonized attapulgite was dispersed in 25 mM Tris-HCl buffer (pH 8.5), and caffeic acid ethylamine was added thereto (the mass ratio of high-temperature carbonized attapulgite to caffeic acid ethylamine was 20:3), and the mixture was reacted at 25°C for 12 hours. After completion, a PCEA film is obtained; the PCEA film is centrifuged, washed, and dried to obtain a polycaffeic acid amine-coated carbonized attapulgite material; the polycaffeic acid amine-coated carbonized attapulgite material is dispersed in deionized water, and 0.10% rhamnose polysaccharide solution is added, and the solid-liquid ratio of the polycaffeic acid amine-coated carbonized attapulgite material to deionized water and rhamnose polysaccharide solution is 1 g:12 mL:3 mL. After reacting for 6 hours, the modified porous attapulgite carrier is obtained after washing and drying.

[0047] (2) Preparation of growth-promoting organic fertilizer: 20 parts of the modified porous attapulgite carrier, 70 parts of cow dung, and 1 part of Bacillus powder (the mass ratio of Bacillus subtilis to Bacillus amyloliquefaciens is 1:1) were mixed evenly, and composting was carried out. The compost was turned over every 2.5 days. The compost temperature was controlled at 47.5°C, the humidity was maintained at 60%, and the pH value was maintained at 6.5. When the temperature dropped to 27.5°C in the late fermentation stage, 20 parts of Anabaena powder (the mass ratio of Spiral Anabaena to Blue-green Anabaena was 2:1), 10 parts of Actinomycetes powder ( The method comprises the following steps: preparing the following: a) a mixture of Streptomyces rosinensis, Streptomyces citrinum, and Streptomyces albiflorus in a mass ratio of 2:1:1; b) a mixture of 2 parts of Trichoderma powder (the mass ratio of Trichoderma harzianum to Trichoderma longibrachiatum being 1:1); adding sterile water in an amount of 4 times the total mass of the three parts; mixing the mixture evenly; conducting a secondary fermentation; maintaining the fermentation humidity at 60%; applying artificial white light; controlling the light intensity at 4000 lux; and providing a light exposure time of 12 hours per day. The fermentation is continued for 11 days to obtain the multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer.

[0048] Example 3

[0049] A method for preparing a multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer comprises the following steps:

[0050] (1) Preparation of modified porous attapulgite carrier: attapulgite powder and chicken manure were mixed evenly in a mass ratio of 1:2, and carbonized for 2.5 hours under a nitrogen atmosphere at 450°C. After the reaction was completed, high-temperature carbonized attapulgite was obtained by grinding; the high-temperature carbonized attapulgite was dispersed in 40 mM Tris-HCl buffer (pH 8.5), and caffeic acid ethylamine was added thereto (the mass ratio of high-temperature carbonized attapulgite to caffeic acid ethylamine was 10:3), and the mixture was reacted at 30°C for 18 hours. The PCEA film should be obtained after completion; the PCEA film is centrifuged, washed, and dried to obtain a polycaffeic acid amine-coated carbonized attapulgite material; the polycaffeic acid amine-coated carbonized attapulgite material is dispersed in deionized water, and 0.15% rhamnose polysaccharide solution is added, and the solid-liquid ratio of the polycaffeic acid amine-coated carbonized attapulgite material to deionized water and rhamnose polysaccharide solution is 1 g:14 mL:6 mL. After reacting for 8 hours, the modified porous attapulgite carrier is obtained after washing and drying.

[0051] (2) Preparation of growth-promoting organic fertilizer: 25 parts of the modified porous attapulgite carrier, 60 parts of cow dung, and 0.5 parts of Bacillus powder (the mass ratio of Bacillus subtilis to Bacillus amyloliquefaciens is 1:2) were mixed evenly, and composting was carried out. The compost was turned over every 2 days. The compost temperature was controlled at 45 ° C, the humidity was maintained at 55%, and the pH value was maintained at 7. When the temperature dropped to 35 ° C in the late fermentation period, 25 parts of Anabaena powder (the mass ratio of Spiral Anabaena to Blue-green Anabaena was 1:1), 8 parts of actinomycete powder (Streptomyces rosinensis, Lemongrass, etc.) were added. The method comprises the following steps: preparing the multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer by mixing the mixture of 1 part of Trichoderma harzianum and 1 part of Streptomyces citriodora and Streptomyces albiflorus in a mass ratio of 1:1:2, 1 part of Trichoderma powder (the mass ratio of Trichoderma harzianum and Trichoderma longibrachiatum is 1:2), adding sterile water at a rate of 5 times the total mass of the three, mixing evenly, and conducting a secondary fermentation. The secondary fermentation is conducted while maintaining the fermentation humidity at 65%. At the same time, artificial white light is added to control the light intensity to 5000 lux and the lighting time to 14 hours / day. The compost is turned every day to enhance the oxygen supply. After fermentation for 15 days, the multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer is obtained.

[0052] Comparative Example 1

[0053] The only difference from Example 1 is that the modified porous attapulgite carrier is replaced by conventional attapulgite powder.

[0054] Comparative Example 2

[0055] The only difference from Example 1 is: (1) Preparation of modified porous attapulgite carrier: attapulgite powder and chicken manure with a mass ratio of 2:1 were mixed evenly, and carbonized at 550°C in a nitrogen atmosphere for 2.5 hours. After the reaction was completed, the high-temperature carbonized attapulgite carrier was obtained by grinding.

[0056] Comparative Example 3

[0057] The only difference from Example 1 is that no Anabaena powder is added.

[0058] Comparative Example 4

[0059] The only difference from Example 1 is that no actinomycete powder is added.

[0060] No fertilization and application of traditional chemical fertilizers were used as blank cases and chemical fertilizer cases, respectively. The organic fertilizers prepared in Examples 1-3 and Comparative Examples 1-4 were applied to the rice planting experiment in cadmium-contaminated farmland. All treatment groups were applied as base fertilizer to the greenhouse paddy fields. All fertilization patterns were consistent with the rice sowing, seedling raising and cultivation management patterns. After the rice was harvested, various functional indicators of the soil and rice were measured, and the soil cadmium removal rate, soil organic matter increment, soil organic carbon increment, total microbial count increment, soil enzyme activity increment, rice yield increase rate, rice grain nitrogen increment and disease and insect pest incidence were calculated. The results are shown in Table 1.

[0061] Table 1 Effects of different fertilization treatments on soil and rice functional indicators

[0062]

[0063]

[0064] As can be seen from Table 1, the blank example has almost no improvement on soil function and rice yield, and the incidence of pests and diseases is the highest. Although the chemical fertilizer example can slightly improve soil organic matter, total microorganisms, soil enzyme activity and rice yield increase rate, the incidence of pests and diseases is still as high as 29.8%, and the soil cadmium removal rate is 0, which fails to effectively reduce the risk of heavy metal pollution in the soil. The soil cadmium removal rate of comparative examples 1-4 gradually increases (26.6%-42.0%), and the soil organic matter, total microorganisms and enzyme activity are all improved to a certain extent, the rice yield increase rate reaches 16.9%-20.5%, and the incidence of pests and diseases is reduced, but the overall effect is still relatively limited, especially in terms of rice grain nitrogen content improvement and pest and disease control. In contrast, the functional organic fertilizers of Examples 1-3 significantly improve the soil cadmium removal rate, improve soil quality, promote rice growth and yield increase, and effectively reduce the occurrence of pests and diseases, which are significantly better than the blank example, chemical fertilizer example and control example. Among them, Example 2 performed the most outstandingly, with a soil cadmium removal rate of up to 55.5%, and had excellent cadmium pollution repair capabilities. The best results were also achieved in soil improvement, microbial increment, and rice yield increase, showing extremely strong biological activity, soil fertility improvement ability, and crop disease resistance potential. Therefore, by optimizing the ratio of modified porous attapulgite carriers, carbonization temperature, strain combination, and fermentation conditions, the prepared multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer can not only significantly repair soil heavy metal pollution, improve soil quality and microbial activity, but also effectively promote the increase in crop yield and quality and enhance the disease resistance of crops, fully reflecting the innovative advantages and wide application value of the organic fertilizer of the present invention in functional synergy, environmentally friendly, seasonal and efficient agricultural production, and has significant ecological and environmental benefits and promotion potential.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer, characterized by: The organic fertilizer comprises the following raw materials in parts by weight: 60-80 parts of cow dung, 15-25 parts of modified porous attapulgite carrier, 0.5-1.5 parts of Bacillus, 15-25 parts of Anabaena powder, 8-12 parts of actinomycete powder, and 1-3 parts of Trichoderma powder.

2. The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer according to claim 1, characterized in that: The modified porous attapulgite carrier is prepared by a method comprising the following steps: (1) mixing attapulgite powder and chicken manure uniformly, performing a carbonization reaction under a nitrogen atmosphere, and grinding to obtain high-temperature carbonized attapulgite after the reaction is completed; (2) dispersing the high-temperature carbonized attapulgite into a buffer solution, adding caffeic acid ethylamine thereto, and obtaining a PCEA film after the reaction is completed; (3) centrifuging, washing, and drying the PCEA film to obtain a polycaffeic acid amine-coated carbonized attapulgite material; (4) The polycaffeic acid amine-coated carbonized attapulgite material is dispersed in deionized water, and a rhamnose polysaccharide solution is added thereto. After the reaction is completed, the modified porous attapulgite carrier is obtained after washing and drying.

3. The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer according to claim 2, characterized in that: The mass ratio of the attapulgite powder to the chicken manure in step 1 is 1-8:1-2; the temperature of the carbonization reaction in step 1 is 450-550° C., and the time is 1.5-2.5 hours.

4. The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer according to claim 2, characterized in that: The buffer in step 2 is Tris-HCl, the pH value of the buffer is 8.5, and the concentration of the buffer is 10-40 mM; the mass ratio of the high-temperature carbonized attapulgite to caffeic acid ethylamine in step 2 is 10:1-3; the temperature of the reaction step in step 2 is 20-30°C, and the reaction time is 6-18 hours.

5. The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer according to claim 2, characterized in that: The solid-liquid ratio of the polycaffeic acid amine-coated carbonized attapulgite material to deionized water and rhamnose polysaccharide solution in step 4 is 1g:9-14mL:1-6mL; the mass concentration of the rhamnose polysaccharide solution in step 4 is 0.05-0.15%; and the reaction time in step 4 is 4-8 hours.

6. The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer according to claim 1, characterized in that: The Bacillus comprises Bacillus subtilis and Bacillus amyloliquefaciens in a mass ratio of 1-2:1-2; the Anabaena powder comprises Anabaena spiralis and Anabaena cyanobacteria in a mass ratio of 1-3:

1.

7. The multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer according to claim 1, characterized in that: The actinomycete powder comprises streptomyces rosinensis, streptomyces citrinum and streptomyces albiflorus in a mass ratio of 1-4:1:0.5-2; the trichoderma powder comprises trichoderma harzianum and trichoderma longibrachiatum in a mass ratio of 1-2:1-2.

8. The method for preparing the multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer according to any one of claims 1 to 7, characterized in that: The steps include: The modified porous attapulgite carrier is evenly mixed with cow dung and Bacillus powder, and compost fermentation is carried out. After the fermentation is completed, the temperature is reduced to 20-35° C., and Anabaena powder, actinomycete powder, Trichoderma powder and sterile water are added thereto. After evenly mixing, secondary fermentation is carried out to obtain the multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer.

9. The method for preparing the multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer according to claim 8, characterized in that: The composting and fermentation steps are specifically as follows: turning the compost once every 2-3 days, maintaining the compost temperature at 45-50°C, the humidity at 55-65%, and the pH at 6-7; and adding sterile water in an amount that is 3-5 times the total mass of the Anabaena powder, the actinomycete powder, and the Trichoderma powder.

10. The method for preparing the multifunctional Anabaena-bacteria composite growth-promoting organic fertilizer according to claim 8, characterized in that: The secondary fermentation step is specifically as follows: turning the compost every day, the fermentation humidity is 55-65%, the fermentation time is 7-15 days, artificial white light is added, the light intensity is 3000-5000 lux, and the lighting time is 10-14 hours / day.

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