Preparation process of biological organic-inorganic compound fertilizer through multi-bacteria synergistic fermentation

Abstract

The invention relates to the technical field of fertilizer production, in particular to a process for preparing a biological organic-inorganic compound fertilizer through multi-bacterium synergistic fermentation, which comprises the following steps: mixing four strains, and activating and culturing through a nano compound; organic materials are treated with compound enzyme and nano materials, and heavy metal is passivated; adding a plurality of functional materials into the mixed material, and carrying out aerobic-microaerobic alternate fermentation and blue light irradiation; the preparation method comprises the following steps: fermenting, aging, carrying out 3D printing-extrusion granulation, carrying out electrostatic spraying of an intelligent coating liquid to obtain sustained-release particles, and carrying out pretreatment such as a pulsed electric field and a plurality of synergistic steps. The process improves the strain activity, greatly increases the viable count, effectively reduces the heavy metal content, and improves the nutrient conversion rate; intelligent slow release of nutrients is achieved, crop yield increase is remarkable, the fertilizer utilization rate is increased, and environment-friendly and economic values are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizer production, in particular to a process for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria synergistic fermentation. Background Art

[0002] Bio-organic-inorganic compound fertilizers combine the long-lasting effects of organic fertilizers, the quick-acting effects of chemical fertilizers, and the growth-promoting properties of biological agents. They have significant advantages in improving soil structure and increasing crop yields, and are widely used in modern agricultural production. However, traditional preparation processes have problems such as low bacterial activity, insufficient nutrient utilization, and a high risk of heavy metal pollution. Conventional fermentation processes only use a single or a few bacterial strains, resulting in weak microbial synergy and a lack of pre-treatment optimization of the bacterial strains. This results in low bacterial survival rates after fertilizers are applied to the soil, making it difficult to perform nitrogen fixation, phosphorus solubilization, and potassium solubilization functions. At the same time, insufficient fermentation of organic materials and poor heavy metal passivation can easily lead to heavy metal accumulation in the soil.

[0003] In terms of fertilizer structure design, traditional processes mostly use simple mixing and granulation, lacking the regulation of nutrient slow-release performance. After fertilizer is applied to the soil, the nutrient release rate does not match the growth needs of crops, resulting in serious fertilizer loss, which not only wastes resources but also pollutes the environment. In addition, the coating materials mostly use ordinary polymers, which cannot respond to environmental changes such as soil temperature, humidity, and pH, making it difficult to achieve precise nutrient release. Moreover, existing processes ignore the application of new functional materials such as photocatalysis and electroresponsiveness. The function of fertilizers in degrading soil pollutants and improving crop resistance is very limited.

[0004] With the advancement of green agricultural development and policies to reduce fertilizer consumption and increase efficiency, the market demand for high-performance bio-organic-inorganic compound fertilizers is becoming increasingly urgent. Traditional processes are no longer able to meet modern agriculture's requirements for efficient, environmentally friendly, and intelligent fertilizer production. There is an urgent need to develop an innovative, comprehensive process, from strain optimization and material processing to intelligent granulation, to enhance fertilizer performance and promote sustainable agricultural development. Summary of the Invention

[0005] (1) Technical problems solved

[0006] In view of the shortcomings of the existing technology, the present invention provides a process for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria synergistic fermentation.

[0007] (2) Technical solution

[0008] A process for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria synergistic fermentation comprises the following steps:

[0009] S1: Bacillus subtilis, Bacillus megaterium phosphate-solubilizing, nitrogen-fixing rhizobia, and a newly introduced salt-tolerant endophyte from Suaeda salsa were mixed and inoculated into an activation medium containing a nano-humic acid-sodium alginate complex, γ-polyglutamic acid, and a novel nanocarbon dot-chitooligosaccharide conjugate; the nanocarbon dot-chitooligosaccharide conjugate was coupled via an amide bond and cultured at 28-32°C and 180-220 rpm for 12-16 hours.

[0010] S2: livestock and poultry manure and crop straw are mixed, a composite enzyme preparation is added, and enzymatic hydrolysis is carried out at 40-50°C for 4-6 hours; nano-iron-chitosan complex and nano-zero-valent iron-biochar composite are added; the composite enzyme preparation comprises cellulase, protease, amylase, and laccase;

[0011] S3: Mixing the pretreated organic material and the activated bacterial culture liquid, adding a composite inorganic salt, a biochar-nano-titanium dioxide composite material, and a light-responsive nano-cerium dioxide-humic acid composite; controlling the moisture content to 50-60% and the pH to 6.5-7.5, and conducting alternating aerobic-microaerobic fermentation at 30-35°C: aerobic (oxygen content 10-12%) for the first 3 days and microaerobic (oxygen content 3-5%) for the last 7 days, during which the compost is turned every 8 hours and irradiated with blue light; the composite inorganic salt comprises potassium nitrate, ammonium dihydrogen phosphate, and potassium sulfate;

[0012] S4: After fermentation, the material is transferred to a sealed warehouse, and nano zinc oxide-sodium lignin sulfonate complex and temperature-responsive poly (N-isopropylacrylamide)-alginate gel microspheres are added. The mixture is aged at 25-30°C for 5-7 days to regulate nutrient release through the temperature-sensitive properties of the gel microspheres.

[0013] S5: Intelligent granulation and coating. The aged material is crushed to 80-100 mesh and granulated using a 3D printing-extrusion composite granulator to form particles with porous interior and regular surface. The coating liquid composed of polyvinyl alcohol, modified starch, nano-silica and graphene quantum dots is then sprayed using electrostatic spray technology to form an intelligent responsive coating layer at 50-60°C.

[0014] Preferably, the method further comprises subjecting the mixed strains to a pulsed electric field treatment before activating the S1 strain, wherein the electric field intensity is 10-15 kV / cm, the pulse frequency is 500-800 Hz, and the treatment time is 2-3 minutes.

[0015] Preferably, the method further comprises spraying a nano-selenium-amino acid chelate solution having a mass fraction of 0.05-0.1% into the fermentation pile every 12 hours during the S3 fermentation process.

[0016] Preferably, the nanocarbon dot particle size of the nanocarbon dot-chitosan oligosaccharide conjugate in S1 is 5-10 nm, and the chitosan oligosaccharide polymerization degree is 5-8.

[0017] Preferably, the nano-zero-valent iron loading of the nano-zero-valent iron-biochar composite material in S2 is 15-20%, and the biochar specific surface area is ≥600m 2 / g.

[0018] Preferably, the particle size of the cerium dioxide in the light-responsive nano-cerium dioxide-humic acid composite in S3 is 20-30 nm.

[0019] Preferably, the particle size of the temperature-responsive poly (N-isopropylacrylamide)-alginate gel microspheres in S4 is 50-100 μm, and the minimum critical solution temperature is 32°C.

[0020] Preferably, the print nozzle diameter of the 3D printing-extrusion composite granulator in S5 is 1-1.5 mm, and the extrusion pressure is 3-5 MPa.

[0021] Preferably, the voltage of the electrostatic spray coating in S5 is 20-25 kV, and the distance between the nozzle and the particle collection is 15-20 cm.

[0022] Preferably, the method further comprises subjecting the finished product to plasma activation treatment, using a helium-oxygen mixed plasma with a power of 200-300W and a treatment time of 5-8 minutes.

[0023] (3) Beneficial technical effects

[0024] Compared with the existing technology, the beneficial effects of the present invention are:

[0025] 1. By introducing salt-tolerant endophytes and adopting pretreatment technologies such as pulsed electric field and plasma, combined with new additives such as nanocarbon dot-chitosan oligosaccharide conjugates, the number of effective live bacteria is increased, the survival rate of bacteria in the soil is improved, and the ability to fix nitrogen and solubilize phosphorus is significantly enhanced.

[0026] 2. The complex enzyme preparation and nano-iron-chitosan complex work synergistically, achieving a removal rate of over 60% for heavy metals such as cadmium and lead. The nano-zero-valent iron-biochar composite also degrades organic toxins, enhancing fertilizer safety. The multi-bacteria synergistic fermentation process, through aerobic-microaerobic alternation, blue light irradiation, and the combination of a light-responsive nano-cerium dioxide complex, not only improves nutrient conversion efficiency but also imparts photocatalytic degradation of soil pollutants to the fertilizer.

[0027] 3. During the secondary aging and intelligent granulation stages, temperature-responsive gel microspheres and a graphene quantum dot coating achieve intelligent, sustained-release of nutrients over a 70-85-day period, improving nutrient utilization. Field trials have shown that fertilizers produced using this process can increase yields of crops such as corn and wheat, while also improving crop quality and increasing the sugar and vitamin content of fruit. Furthermore, the process is environmentally friendly, reducing fertilizer use and alleviating agricultural non-point source pollution, resulting in significant economic and ecological benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a process flow chart for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria synergistic fermentation disclosed by the present invention;

[0029] Figure 2 3. It is a line comparison chart of the total content of nitrogen, phosphorus and potassium and the organic matter content of the embodiment and the comparative example;

[0030] Figure 3 1. This is a comparison chart of the yield increase rate of corn potted plants and heavy metal cadmium residues in the embodiment and the comparative example;

[0031] Figure 4 It is a radar comparison chart produced after unifying the dimensions of the performance data of the embodiment and the comparative example. DETAILED DESCRIPTION

[0032] according to Figures 1 to 4 , the specific implementation methods of the present invention are as follows:

[0033] Example 1: Preparation of bio-organic-inorganic compound fertilizer by multi-bacteria synergistic fermentation

[0034] S1: Pretreatment of bacterial strains

[0035] Bacillus subtilis, Bacillus megaterium phosphate-solubilizing, nitrogen-fixing rhizobium, and endophytes from Suaeda salsa were mixed in a volume ratio of 1:1:0.8:0.5. An activation medium was prepared by adding 20g of glucose, 5g of yeast extract, 0.4g of nanohumic acid-sodium alginate complex, 0.3g of γ-polyglutamic acid, and 0.15g of a nanocarbon dot-oligochitosan conjugate to 1L of deionized water. The nanocarbon dot-oligochitosan conjugate was prepared by dissolving 50mg of nanocarbon dots (8nm particle size) and 100mg of chitosan oligosaccharide (DP 6) in 50mL of deionized water. 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) 80mg and N-hydroxysuccinimide (NHS) 60mg were added. The mixture was stirred at room temperature for 6 hours, purified by dialysis, and lyophilized for later use. The mixed strains were inoculated into the activation culture medium and cultured in a shaking incubator at 30°C and 200 rpm for 14 hours. During this period, samples were taken every 4 hours for microscopic examination to observe the activity of the strains.

[0036] S2: Organic material pretreatment

[0037] 300 kg of fresh chicken manure (60% moisture content) was mixed with 200 kg of corn straw (crushed to 2-3 cm), and 4 kg of a composite enzyme preparation (cellulase activity 10,000 U / g, protease activity 5,000 U / g, amylase activity 3,000 U / g, laccase activity 1,000 U / g, mass ratio 3:2:1:0.5) was added. The mixture was piled up for enzymatic hydrolysis at 45°C for 5 hours. After enzymatic hydrolysis, 1.5 kg of nano-iron-chitosan complex (nano-iron particle size 30 nm, chitosan deacetylation degree 92%) and nano-zero-valent iron-biochar composite (nano-zero-valent iron loading 18%, biochar specific surface area 650 m2) were added. 2 / g)0.75kg, fully stirred, and the heavy metal cadmium and lead contents were detected to decrease by 40% and 35% respectively.

[0038] S3: Multi-bacteria cooperative fermentation

[0039] The pretreated organic material was transferred to the fermentation tank, 100L of activated bacterial liquid was added, and composite inorganic salts (potassium nitrate 40kg, ammonium dihydrogen phosphate 30kg, potassium sulfate 20kg), biochar-nano titanium dioxide composite material (biochar specific surface area 550m 2 / g, titanium dioxide loading 12%) 3kg, light-responsive nano-cerium dioxide-humic acid composite (cerium dioxide particle size 25nm) 0.75kg. Adjust the moisture content to 55%, pH to 7.0, and use an automatic turning machine to turn the pile every 8 hours. Open the ventilation system for the first 3 days to maintain an oxygen content of 11%, and reduce the ventilation volume for the next 7 days to maintain the oxygen content at 4%. At the same time, irradiate with blue light for 6 hours every day (wavelength 420nm, intensity 65μmol / m 2 ·s). During the fermentation process, the changes in temperature, pH and ammonium nitrogen content were monitored and the fermentation curve was drawn.

[0040] S4: Secondary aging treatment

[0041] After fermentation, the material is transferred to a sealed aging chamber, where 1 kg of nano zinc oxide-sodium lignin sulfonate complex (zinc oxide particle size 50 nm) and 0.5 kg of temperature-responsive poly (N-isopropylacrylamide)-alginate gel microspheres (particle size 80 μm) are added and aged at 28°C for 6 days. During the aging period, samples are taken every two days to measure the moisture and humic acid content to ensure that the humic acid content is increased to above 25%.

[0042] S5: Intelligent granulation and coating

[0043] The aged material was crushed to 90 mesh and granulated using a 3D printing-extrusion composite granulator (nozzle diameter 1.2mm, extrusion pressure 4MPa) to form particles with a diameter of 3mm and an internal porosity of 25%. The coating liquid was prepared by dissolving 25kg of polyvinyl alcohol, 15kg of octenylsuccinic anhydride-modified starch (degree of substitution 0.02), 10kg of nano-silica, and 5kg of graphene quantum dots in 200L of deionized water and ultrasonically dispersing them for 30 minutes. The coating was carried out at 55°C using an electrostatic spray device (voltage 22kV, nozzle distance 18cm) to form a 0.2mm thick coating layer. The compressive strength of the particles was tested to reach 15N / particle.

[0044] Example 2: Preparation of high stress resistance bio-organic-inorganic compound fertilizer

[0045] S1: Pretreatment of bacterial strains

[0046] Bacillus subtilis, Bacillus megaterium phosphate-solubilizing, nitrogen-fixing rhizobium, and endophytes from Suaeda salsa were mixed in a volume ratio of 1:1:0.8:0.6. The activation medium was prepared by adding 20g of glucose, 5g of yeast extract, 0.5g of nanohumic acid-sodium alginate complex, 0.3g of γ-polyglutamic acid, and 0.2g of a nanocarbon dot-chitosan oligosaccharide conjugate to 1L of deionized water. The nanocarbon dot-chitosan oligosaccharide conjugate was prepared by dissolving 100mg of nanocarbon dots (8nm particle size) and 200mg of chitosan oligosaccharide (DP 6) in 50mL of deionized water, adding 160mg of EDC and 120mg of NHS, stirring at room temperature for 6 hours, dialysis purification, and freeze-drying for later use. Before activation, the bacteria were treated with a pulsed electric field: the bacterial suspension was placed between parallel electrodes spaced 1cm apart and a pulsed electric field of 12kV / cm and 600Hz was applied for 2.5 minutes. The mixed strains were inoculated into the activation culture medium and cultured in a shaking incubator at 32°C and 220 rpm for 16 hours. During this period, samples were taken every 4 hours for microscopic examination to observe the activity of the strains.

[0047] S2: Organic material pretreatment

[0048] 300 kg of fresh pig manure (65% moisture content) was mixed with 200 kg of wheat straw (crushed to 2-3 cm), and 5 kg of a composite enzyme preparation (cellulase activity 10,000 U / g, protease activity 5,000 U / g, amylase activity 3,000 U / g, laccase activity 1,000 U / g, mass ratio 3:2:1:0.5) was added. The mixture was piled up for enzymatic hydrolysis at 50°C for 4 hours, and stirred every 2 hours. After enzymatic hydrolysis, 2 kg of nano-iron-chitosan complex (nano-iron particle size 30 nm, chitosan deacetylation degree 92%) and nano-zero-valent iron-biochar composite (nano-zero-valent iron loading 18%, biochar specific surface area 650 m2) were added. 2 / g)1kg, fully stirred, and the heavy metal cadmium and lead contents were detected to decrease by 45% and 40% respectively.

[0049] S3: Multi-bacteria cooperative fermentation

[0050] The pretreated organic material was transferred to the fermentation tank, 120L of activated bacterial liquid was added, and composite inorganic salts (50kg potassium nitrate, 30kg ammonium dihydrogen phosphate, 20kg potassium sulfate), biochar-nano titanium dioxide composite material (biochar specific surface area 550m 2 / g, titanium dioxide loading 12%) 4kg, light-responsive nano-cerium dioxide-humic acid complex (cerium dioxide particle size 25nm) 1kg. Adjust the water content to 58%, pH to 7.2, and use an automatic turning machine to turn the pile every 6 hours. Maintain a micro-aerobic environment (oxygen content 3-5%) throughout the fermentation process, and irradiate with blue light for 8 hours every day (wavelength 420nm, intensity 80μmol / m 2 ·s). During the fermentation process, the changes in temperature, pH and ammonium nitrogen content were monitored and the fermentation curve was drawn.

[0051] S4: Secondary aging treatment

[0052] After fermentation, the material was transferred to a sealed aging chamber, where 1.2 kg of a nano-zinc oxide-sodium lignin sulfonate complex (zinc oxide particle size 50 nm) and 0.8 kg of temperature-responsive poly (N-isopropylacrylamide)-alginate gel microspheres (particle size 80 μm) were added and aged at 25°C for 7 days. During the aging period, samples were taken every two days to measure the moisture and humic acid content to ensure that the humic acid content was increased to above 28%.

[0053] S5: Intelligent granulation and coating

[0054] The aged material was crushed to 90 mesh and granulated using a 3D printing-extrusion composite granulator (nozzle diameter 1.5mm, extrusion pressure 5MPa) to form particles with a diameter of 3.5mm and an internal porosity of 30%. The coating liquid was prepared by dissolving 25kg of polyvinyl alcohol, 15kg of octenylsuccinic anhydride-modified starch (degree of substitution 0.02), 10kg of nano-silica, and 7.5kg of graphene quantum dots in 200L of deionized water and ultrasonically dispersing them for 30 minutes. The coating was carried out using an electrostatic spray device (voltage 25kV, nozzle distance 18cm, temperature 55°C) to form a 0.3mm thick coating layer. The compressive strength of the particles was tested to reach 18N / particle.

[0055] Example 3: Preparation of high-efficiency slow-release bio-organic-inorganic compound fertilizer

[0056] S1: Pretreatment of bacterial strains

[0057] Bacillus subtilis, Bacillus megaterium phosphate-solubilizing, nitrogen-fixing rhizobia, and endophytes from Suaeda salsa (laboratory isolation and screening) were mixed in a volume ratio of 1:1:0.8:0.5. The activation medium was prepared by adding 20g of glucose, 5g of yeast extract, 0.4g of a nano-humic acid-sodium alginate complex, 0.2g of γ-polyglutamic acid, and 0.05g of a nano-selenium-amino acid chelate (15% selenium content) to 1L of deionized water. The nano-selenium-amino acid chelate was prepared by reacting sodium selenate with glycine and lyophilized for later use. Before activation, the strains were treated with a low-temperature plasma at 120W for 4 minutes. The mixed strains were then inoculated into the activation medium and incubated at 28°C, 200rpm, and shaker for 12 hours. Samples were taken every 3 hours for microscopic examination of the activity.

[0058] S2: Organic material pretreatment

[0059] 300 kg of fresh cow dung (58% moisture content) was mixed with 200 kg of rice straw (crushed to 2-3 cm), and 4.5 kg of a composite enzyme preparation (cellulase activity 10,000 U / g, protease activity 5,000 U / g, amylase activity 3,000 U / g, laccase activity 1,000 U / g, mass ratio 3:2:1:0.5) was added. The mixture was piled up for enzymatic hydrolysis at 42°C for 6 hours, and stirred every 3 hours. After enzymatic hydrolysis, 1.8 kg of nano-iron-chitosan complex (nano-iron particle size 30 nm, chitosan deacetylation degree 92%) and nano-zero-valent iron-biochar composite (nano-zero-valent iron loading 18%, biochar specific surface area 650 m2) were added. 2 / g)0.9kg, stirred thoroughly, and the heavy metal cadmium and lead contents were detected to decrease by 38% and 33% respectively.

[0060] S3: Multi-bacteria cooperative fermentation

[0061] The pretreated organic material was transferred to the fermentation tank, 100L of activated bacterial liquid was added, and composite inorganic salts (potassium nitrate 40kg, ammonium dihydrogen phosphate 30kg, potassium sulfate 20kg), biochar-nano titanium dioxide composite material (biochar specific surface area 550m 2 / g, titanium dioxide loading 12%) 3.5kg, light-responsive nano-cerium dioxide-humic acid complex (cerium dioxide particle size 25nm) 0.8kg. Adjust the moisture content to 55%, pH to 7.0, and use an automatic turning machine to turn the pile every 8 hours. Turn on the ventilation system for the first 3 days to maintain an oxygen content of 12%, and reduce the ventilation volume to maintain the oxygen content at 5% for the next 7 days. At the same time, spray 5L of nano-selenium-amino acid chelate solution (mass fraction 0.08%) every 12 hours every day. Monitor changes in temperature, pH and ammonium nitrogen content during the fermentation process and draw a fermentation curve.

[0062] S4: Secondary aging treatment

[0063] After fermentation, the material was transferred to a sealed aging chamber, where 1.1 kg of a nano-zinc oxide-sodium lignin sulfonate complex (zinc oxide particle size 50 nm) and 0.6 kg of temperature-responsive poly (N-isopropylacrylamide)-alginate gel microspheres (particle size 80 μm) were added and aged at 30°C for 5 days. During the aging period, samples were taken every other day to measure the moisture and humic acid content to ensure that the humic acid content was increased to above 26%.

[0064] S5: Intelligent granulation and coating

[0065] The aged material was crushed to 100 mesh and granulated using a 3D printing-extrusion composite granulator (nozzle diameter 1mm, extrusion pressure 3MPa) to form particles with a diameter of 2.5mm and an internal porosity of 28%. The coating liquid was prepared by dissolving 30kg of polyvinyl alcohol, 15kg of octenylsuccinic anhydride-modified starch (degree of substitution 0.02), 8kg of nano-silica, and 4kg of graphene quantum dots in 200L of deionized water and ultrasonically dispersing them for 25 minutes. The coating was performed using an electrostatic spray device (voltage 20kV, nozzle distance 20cm, temperature 50°C) to form a 0.15mm thick coating layer. The compressive strength of the particles was tested to reach 12N / particle.

[0066] Comparative Example: Traditional Bio-Organic Fertilizer Preparation Process

[0067] Step 1: Bacteria processing

[0068] Only Bacillus subtilis was used, inoculated into ordinary LB medium, and cultured at 30°C for 12 hours without any modification.

[0069] Step 2: Material pretreatment

[0070] After chicken manure was mixed with corn straw, only cellulase (2 kg) was added and enzymatic hydrolysis was carried out at 50°C for 3 hours without adding heavy metal passivator.

[0071] Step 3: Fermentation

[0072] Urea, superphosphate and potassium sulfate (total addition amount 5%) were added and the compost was fermented naturally for 15 days without oxygen and light control.

[0073] Step 4: Post-processing

[0074] After fermentation, it is directly crushed and sieved without aging, granulation or coating. The finished product is in powder form.

[0075] The key performance comparisons of the examples and the comparative examples are shown in the following table:

[0076] Table 1

[0077]

[0078]

[0079] The comparison of the addition amount of functional ingredients in the examples is shown in the following table:

[0080] Table 2

[0081] Test items Example 1 Example 2 Example 3 Nanocarbon dots-chitosan oligosaccharide conjugate (g / L) 0.15 0.2 0.15 Nano-selenium-amino acid chelate (g / L) 0 0 0.05 Photoresponsive nano-cerium dioxide composite (kg) 0.75 1 0.8 Temperature-responsive gel microspheres (kg) 0.5 0.8 0.6 Proportion of graphene quantum dots in coating solution (%) 1 1.5 1.2

[0082] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A process for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria synergistic fermentation, characterized in that: The following steps are involved: S1: Bacillus subtilis, Bacillus megaterium phosphate-solubilizing, nitrogen-fixing rhizobia, and a newly introduced salt-tolerant endophyte from Suaeda salsa were mixed and inoculated into an activation medium containing a nano-humic acid-sodium alginate complex, γ-polyglutamic acid, and a novel nanocarbon dot-chitooligosaccharide conjugate; the nanocarbon dot-chitooligosaccharide conjugate was coupled via an amide bond and cultured at 28-32°C and 180-220 rpm for 12-16 hours. S2: livestock and poultry manure and crop straw are mixed, a composite enzyme preparation is added, and enzymatic hydrolysis is carried out at 40-50°C for 4-6 hours; nano-iron-chitosan complex and nano-zero-valent iron-biochar composite are added; the composite enzyme preparation comprises cellulase, protease, amylase, and laccase; S3: Mixing the pretreated organic material and the activated bacterial culture liquid, adding a composite inorganic salt, a biochar-nano-titanium dioxide composite material, and a light-responsive nano-cerium dioxide-humic acid composite; controlling the moisture content to 50-60% and the pH to 6.5-7.5, and conducting alternating aerobic-microaerobic fermentation at 30-35°C: aerobic (oxygen content 10-12%) for the first 3 days and microaerobic (oxygen content 3-5%) for the last 7 days, during which the compost is turned every 8 hours and irradiated with blue light; the composite inorganic salt comprises potassium nitrate, ammonium dihydrogen phosphate, and potassium sulfate; S4: After fermentation, the material is transferred to a sealed warehouse, and nano zinc oxide-sodium lignin sulfonate complex and temperature-responsive poly (N-isopropylacrylamide)-alginate gel microspheres are added. The mixture is aged at 25-30°C for 5-7 days to regulate nutrient release through the temperature-sensitive properties of the gel microspheres. S5: Intelligent granulation and coating. The aged material is crushed to 80-100 mesh and granulated using a 3D printing-extrusion composite granulator to form particles with porous interior and regular surface. The coating liquid composed of polyvinyl alcohol, modified starch, nano-silica and graphene quantum dots is then sprayed using electrostatic spray technology to form an intelligent responsive coating layer at 50-60°C.

2. The process for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria cooperative fermentation according to claim 1, characterized in that: The method also includes subjecting the mixed bacteria to pulse electric field treatment before activating the S1 bacteria, with an electric field strength of 10-15 kV / cm, a pulse frequency of 500-800 Hz, and a treatment time of 2-3 minutes.

3. The process for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria cooperative fermentation according to claim 1, characterized in that: The method further comprises spraying a nano-selenium-amino acid chelate solution with a mass fraction of 0.05-0.1% into the fermentation pile every 12 hours during the S3 fermentation process.

4. The process for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria cooperative fermentation according to claim 1, characterized in that: The nanocarbon dot particle size of the nanocarbon dot-chitosan oligosaccharide conjugate in S1 is 5-10 nm, and the chitosan oligosaccharide polymerization degree is 5-8.

5. The process for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria cooperative fermentation according to claim 1, characterized in that: The nano-zero-valent iron loading of the nano-zero-valent iron-biochar composite material in S2 is 15-20%, and the biochar specific surface area is ≥600m 2 / g.

6. The process for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria cooperative fermentation according to claim 1, characterized in that: The particle size of the cerium dioxide in the light-responsive nano-cerium dioxide-humic acid composite in S3 is 20-30 nm.

7. The process for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria cooperative fermentation according to claim 1, characterized in that: The particle size of the temperature-responsive poly (N-isopropylacrylamide)-alginate gel microspheres in S4 is 50-100 μm, and the minimum critical solution temperature is 32° C.

8. The process for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria cooperative fermentation according to claim 1, characterized in that: The print nozzle diameter of the 3D printing-extrusion composite granulator in S5 is 1-1.5 mm, and the extrusion pressure is 3-5 MPa.

9. The process for preparing a bio-organic-inorganic compound fertilizer by multi-bacteria cooperative fermentation according to claim 1, characterized in that: The voltage of the electrostatic spray coating in S5 is 20-25 kV, and the distance between the nozzle and the particle collection is 15-20 cm.

10. The process for preparing bio-organic-inorganic compound fertilizer by multi-bacteria synergistic fermentation according to claim 1, characterized in that: It also includes plasma activation treatment of the finished product, using helium-oxygen mixed plasma with a power of 200-300W and a treatment time of 5-8 minutes.

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