Biological organic fertilizer and preparation method thereof

Abstract

The invention provides a biological organic fertilizer and a preparation method thereof. The biological organic fertilizer is prepared from the following raw materials in parts by weight: 10 to 15 parts of rice husk, 8 to 12 parts of peanut shell, 10 to 15 parts of bagasse, 15 to 20 parts of straw, 20 to 25 parts of livestock manure, 5 to 10 parts of pond sludge, 3 to 5 parts of plant ash, 5 to 10 parts of oil meal, 5 to 10 parts of ammonium phosphate, 2 to 5 parts of low-temperature complex microbial inoculants, 3 to 6 parts of seaweed oligosaccharide, 5 to 10 parts of modified vermiculite powder and 10 to 20 parts of photothermal conversion microspheres. According to the invention, waste is taken as a basic raw material and is matched with ammonium phosphate to rapidly supplement available nutrients, and meanwhile, the low-temperature complex microbial inoculant, the modified vermiculite powder and the photothermal conversion microspheres are introduced to form a synergistic interaction system. Vermiculite powder is modified, so that the nutrient adsorption and slow release capability is improved, a carbon source and low-temperature protection are provided for microorganisms, and the cell membrane stability is enhanced. The photothermal conversion microspheres efficiently absorb sunlight and convert the sunlight into heat energy, a local and mild heat island effect is formed around the fungicide, the microenvironment temperature is increased, breeding of the fungicide is remarkably accelerated, and therefore organic matter decomposition and nitrogen conversion are accelerated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bio-organic fertilizer, and particularly relates to a bio-organic fertilizer and a preparation method thereof. BACKGROUND

[0002] As an important support for sustainable development of agriculture, bio-organic fertilizer is widely used in modern agricultural production due to its advantages of improving soil structure, enhancing soil fertility and reducing abuse of chemical fertilizer. At present, the raw materials of bio-organic fertilizer are mainly derived from organic wastes such as livestock and poultry manure, crop straw, kitchen waste and municipal sludge, which are made through composting and fermentation processes.

[0003] However, the application effect of the existing bio-organic fertilizer in a low-temperature environment has obvious limitations. The microbial strains added in the prior art are mainly normal-temperature adaptive strains (such as ordinary Bacillus subtilis and nitrogen-fixing bacteria), and the optimal metabolic temperature thereof is 25-35℃. When the soil temperature is less than 10℃, the activity of the strains is significantly inhibited, which leads to a significant decrease in the decomposition rate of organic matter in the fertilizer. At the same time, the nitrogen and phosphorus in the organic matter in the fertilizer can be absorbed by crops only through microbial conversion, and the conversion process is hindered under low-temperature conditions, which leads to low nitrogen mineralization efficiency. In the early spring and winter scenes, the nitrogen mineralization rate of such bio-organic fertilizer is only 1 / 3-1 / 2 of that under normal temperature (25-30℃), and the soil available nitrogen content is usually ≤30 mg / kg within 7 days after the fertilizer is applied to the soil, which cannot meet the nutrient demand of crops in the critical growth period. Therefore, the existing bio-organic fertilizer has the defects of insufficient activity of functional microorganisms and low nitrogen mineralization rate under low-temperature conditions. SUMMARY

[0004] In view of this, the present application provides a bio-organic fertilizer and a preparation method thereof to solve the above problems.

[0005] The technical scheme of the present application is as follows:

[0006] The bio-organic fertilizer comprises the following raw materials in parts by weight: 10-15 parts of rice husk, 8-12 parts of peanut shell, 10-15 parts of sugarcane residue, 15-20 parts of straw, 20-25 parts of livestock manure, 5-10 parts of pond mud, 3-5 parts of wood ash, 5-10 parts of oil meal, 5-10 parts of ammonium phosphate, 2-5 parts of low-temperature composite microbial agent, 3-6 parts of seaweed oligosaccharide, 5-10 parts of modified vermiculite powder and 10-20 parts of light-heat conversion microspheres.

[0007] The modified vermiculite powder is obtained through a two-step method of hydrochloric acid pretreatment and humic acid-proline complex modification.

[0008] Further, the low-temperature composite microbial agent is compounded by cold-resistant Bacillus and low-temperature Pseudomonas at a mass ratio of (3-5):(1.8-2.2), wherein the viable count of the cold-resistant Bacillus is ≥3.0×108 CFU / g, the bacterial activity of Pseudomonas is ≥2.0×10 8 CFU / g.

[0009] Further, the modified vermiculite powder is prepared by the following method:

[0010] A. Crush the vermiculite raw ore to obtain vermiculite powder, soak the vermiculite powder in a hydrochloric acid solution, treat in a water bath at 80-85°C for 2-4h, then wash with water to neutral, and dry at 60-80°C for 4-6h to obtain pretreated vermiculite powder;

[0011] B. Mix the pretreated vermiculite powder with a humic acid solution, then add a proline solution, stir and adsorb at 30-40°C for 4-6h, then vacuum dry at 50-60°C for 8-12h to obtain modified vermiculite powder.

[0012] Further, in step A, the concentration of the hydrochloric acid solution is 10-15wt%, the solid-liquid ratio Kg / L of the vermiculite powder to the hydrochloric acid solution is 1:(5-8), and the particle size of the vermiculite powder is 0.5-2mm.

[0013] Further, in step B, the concentration of the humic acid solution is 5-10wt%, the concentration of the proline solution is 0.3-1.0wt%, the solid-liquid ratio Kg / L of the pretreated vermiculite powder to the humic acid solution is 1:(3-5), and the addition amount of the proline solution is 2-5% of the volume of the humic acid solution.

[0014] Further, the molecular weight of the sea algal oligosaccharide is 500-1000Da.

[0015] Further, the ammonium phosphate is a 1:1 compound of ammonium dihydrogen phosphate and diammonium hydrogen phosphate, and the oil meal is one or a combination of several of rapeseed meal, peanut meal, sesame meal, and tea seed meal.

[0016] Further, the photo-thermal conversion microspheres are prepared by the following method: the fresh cuttlefish ink sac is washed with deionized water, the ink sac is cut open, and the ink is collected. The ink is frozen at -60 to -80℃ for 20 to 30 hours, and then crushed through a 40 to 80 mesh screen. The ink powder is obtained by drying the crushed ink powder in a vacuum drying oven at 50 to 60℃ for 10 to 15 hours. The ink powder is mixed with a 2 to 4 wt% sodium alginate solution at a mass / volume ratio of 1:4 to 6, and then homogenized at a speed of 8000 to 12000 rpm for 5 to 15 minutes to form a uniform slurry. The slurry is then sprayed to form the microsphere core by spray drying, with the inlet temperature controlled at 140 to 160℃, the outlet temperature controlled at 70 to 85℃, and the feeding rate adjusted to 5 to 10 mL / min. Then, using a fluidized bed coating device, a 1.0 to 2.0 wt% chitosan acetic acid solution and a 2.0 to 3.0 wt% calcium chloride solution are used as coating materials, and the coating is alternately sprayed 3 to 5 times at a fluidization temperature of 40 to 50℃. After each spraying, the coating is allowed to penetrate for 5 to 10 minutes, and then dried at a fluidization temperature of 45 to 55℃ for 30 to 60 minutes to obtain the photo-thermal conversion microspheres.

[0017] Further, a method for preparing a bio-organic fertilizer comprises the following steps:

[0018] S1, the rice husk, peanut shell, sugarcane residue and straw are crushed to a particle size of ≤3mm to obtain a plant raw material mixture. A composite enzyme is added to the plant raw material mixture at a mass fraction of 0.1 to 0.3%, and the moisture content is adjusted to 40 to 50%. The mixture is subjected to closed enzymolysis at 45 to 50℃ for 12 to 18 hours to obtain pretreated raw materials.

[0019] S2, the pretreated raw materials are mixed with poultry manure, pond mud and oil meal, and the moisture content is adjusted to 40 to 50%. An anaerobic-aerobic alternating fermentation mode is used: first, the mixture is subjected to closed anaerobic fermentation at 15 to 20℃ for 5 to 7 days, then the pile is turned over for aerobic fermentation, the pile temperature is controlled at ≤40℃, the pH value is adjusted to 6.5 to 7.5, and the aerobic fermentation is carried out for 3 to 4 days. Then, the next round of anaerobic fermentation is carried out, and the alternating process is repeated for 3 to 4 cycles. After fermentation, the material is dried at 40 to 45℃ for 22 to 26 hours to obtain fermented material.

[0020] S3, the fermented material, ammonium phosphate, wood ash, low-temperature composite microbial agent, algal oligosaccharide, modified vermiculite powder and photo-thermal conversion microspheres are mixed, stirred at 60 to 150 rpm for 20 to 30 minutes, and then dried at 35 to 40℃ for 10 to 15 hours. The mixture is then crushed through a 20 to 40 mesh screen to obtain a bio-organic fertilizer.

[0021] Furthermore, the complex enzyme in S1 is composed of β-glucanase, β-glucosidase, and xylanase in a mass ratio of (6.0-8.0):(1.5-2.0):(1.0-1.5), with β-glucanase activity ≥10000U / g, β-glucosidase activity ≥5000U / g, and xylanase activity ≥8000U / g.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. This application uses agricultural waste as a base material, combined with ammonium phosphate for rapid replenishment of readily available nutrients, and introduces a low-temperature compound microbial agent, modified vermiculite powder, and photothermal conversion microspheres to form a synergistic system. The modified vermiculite powder, after two-step modification, enhances nutrient adsorption and slow-release capabilities, provides a carbon source and low-temperature protection for microorganisms, and strengthens cell membrane stability. The photothermal conversion microspheres efficiently absorb sunlight and convert it into heat energy, creating a localized, mild "heat island effect" around the microbial agent, raising the microenvironment temperature by 1-3°C, thereby significantly accelerating its reproduction. This results in a substantial increase in the activity of the low-temperature compound microbial agent in a suitable microenvironment, accelerating organic matter decomposition and nitrogen conversion. Ultimately, this significantly enhances the activity of functional bacteria in the fertilizer under low-temperature conditions, significantly improves nitrogen mineralization efficiency, and, after application to the soil, quickly meets the nutrient needs of crops under low-temperature conditions, effectively solving the problem of slow growth under low-temperature conditions, achieving a breakthrough improvement in fertilizer efficiency at low temperatures.

[0024] 2. The bio-organic fertilizer provided in this application simultaneously enhances crop stress resistance and nutrient supply capacity. The addition of seaweed oligosaccharides allows for direct absorption by crop roots, regulating the synthesis of osmotic regulators and significantly enhancing root resistance under low temperatures. It also stimulates rhizosphere microbial proliferation, indirectly improving nitrogen mineralization efficiency. Modified vermiculite powder enhances nutrient adsorption and slow release, and, combined with a suitable blend of ammonium phosphate, achieves a balanced supply of nitrogen and phosphorus nutrients. The synergistic effect of functional microbial agents continuously decomposes organic matter, providing long-term nutrient support for crops and comprehensively improving crop growth performance under low-temperature conditions. The photothermal conversion microspheres, by increasing the local microenvironmental temperature, also promote root growth, thereby encouraging early crop development. The squid ink powder in the photothermal conversion microspheres is rich in nitrogen, carbon, and various trace elements. Its slow degradation in the soil further replenishes the soil's nutrients, providing natural nutrition for soil microorganisms and crops.

[0025] 3. This application uses agricultural waste such as rice husks, straw, and livestock manure as main raw materials. Through standardized production processes, it achieves efficient resource utilization of waste, reduces environmental pollution, and lowers fertilizer production costs. The preparation process employs low-temperature fermentation technology, coupled with precise parameter control, to avoid the destruction of active ingredients at high temperatures and ensure the stability of the effective components in the finished product. Detailed Implementation

[0026] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0027] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0028] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0029] Example 1

[0030] A bio-organic fertilizer comprises the following raw materials in parts by weight: 10 parts rice husk, 8 parts peanut shell, 10 parts sugarcane bagasse, 15 parts straw, 20 parts poultry and livestock manure, 5 parts pond mud, 3 parts wood ash, 5 parts oilseed meal, 5 parts ammonium phosphate, 2 parts low-temperature compound microbial agent, 3 parts seaweed oligosaccharide, 5 parts modified vermiculite powder, and 10 parts photothermal conversion microspheres. The low-temperature compound microbial agent is composed of cold-resistant Bacillus and low-temperature Pseudomonas in a mass ratio of 3:1.8, wherein the viable count of the cold-resistant Bacillus is ≥3.0 × 10⁻⁶. 8 CFU / g, viable count of *Pseudomonas pyrophila* ≥ 2.0 × 10⁻⁶ 8 CFU / g. The molecular weight of the seaweed oligosaccharide is 500 Da. The ammonium phosphate is a 1:1 mixture of ammonium dihydrogen phosphate and diammonium hydrogen phosphate, and the oil meal is rapeseed meal.

[0031] The modified vermiculite powder was obtained through a two-step method of hydrochloric acid pretreatment and humic acid-proline composite modification, and was prepared by the following method:

[0032] A. The raw vermiculite ore is crushed to a particle size of 0.5 mm to obtain vermiculite powder. The vermiculite powder is soaked in a 10 wt% hydrochloric acid solution with a solid-liquid ratio of 1:5 kg / L between the vermiculite powder and the hydrochloric acid solution. The mixture is then treated in a water bath at 80°C for 4 hours, washed with water until neutral, and dried at 60°C for 6 hours to obtain pretreated vermiculite powder.

[0033] B. Pretreated vermiculite powder was mixed with a 5 wt% humic acid solution, with a solid-liquid ratio of 1:3 (kg / L). Then, a 0.3 wt% proline solution was added, with the amount of proline solution added being 2% of the volume of the humic acid solution. The mixture was stirred and adsorbed at 30°C for 6 hours, and then vacuum dried at 50°C for 12 hours to obtain modified vermiculite powder.

[0034] The photothermal conversion microspheres were prepared by the following method: Fresh cuttlefish ink sacs were rinsed with deionized water, the ink sacs were cut open, and the ink was collected. The ink was frozen at -60℃ for 30 hours, then pulverized and passed through a 40-mesh sieve, and subsequently dried in a vacuum drying oven at 50℃ for 15 hours to obtain cuttlefish ink powder. The cuttlefish ink powder was mixed with a 2wt% sodium alginate solution at a mass-to-volume ratio of 1:4 (kg / L), and homogenized at 8000 rpm for 15 minutes to form a uniform slurry. This slurry was then... The microsphere cores were prepared by spray drying, with the inlet air temperature controlled at 140℃, the outlet air temperature controlled at 70℃, and the feed flow rate adjusted to 5mL / min. Subsequently, a fluidized bed coating device was used, with a 1.0wt% chitosan acetic acid solution and a 2.0wt% calcium chloride aqueous solution as coating materials. The coatings were sprayed alternately three times at a fluidization temperature of 40℃, and allowed to stand for 5 minutes after each spraying. Finally, the microspheres were fluidized and dried at 45℃ for 60 minutes to obtain photothermal conversion microspheres.

[0035] Example 2

[0036] A bio-organic fertilizer comprises the following raw materials in parts by weight: 15 parts rice husk, 12 parts peanut shell, 15 parts sugarcane bagasse, 20 parts straw, 25 parts poultry and livestock manure, 10 parts pond mud, 5 parts wood ash, 10 parts oilseed meal, 10 parts ammonium phosphate, 5 parts low-temperature compound microbial agent, 6 parts seaweed oligosaccharide, 10 parts modified vermiculite powder, and 20 parts photothermal conversion microspheres; wherein the low-temperature compound microbial agent is composed of cold-resistant Bacillus and low-temperature Pseudomonas in a mass ratio of 5:2.2, and the viable count of the cold-resistant Bacillus is ≥3.0×10⁻⁶. 8 CFU / g, viable count of *Pseudomonas pyrophila* ≥ 2.0 × 10⁻⁶ 8 CFU / g. The molecular weight of the seaweed oligosaccharide is 1000 Da. The ammonium phosphate is a 1:1 mixture of ammonium dihydrogen phosphate and diammonium hydrogen phosphate, and the oil meal is a 1:1 combination of peanut meal and sesame meal.

[0037] The modified vermiculite powder was obtained through a two-step method of hydrochloric acid pretreatment and humic acid-proline composite modification, and was prepared by the following method:

[0038] A. The raw vermiculite ore is crushed to a particle size of 2 mm to obtain vermiculite powder. The vermiculite powder is soaked in a 15 wt% hydrochloric acid solution with a solid-liquid ratio of 1:8 kg / L between the vermiculite powder and the hydrochloric acid solution. The mixture is then treated in a water bath at 85°C for 2 hours, washed with water until neutral, and dried at 80°C for 4 hours to obtain pretreated vermiculite powder.

[0039] B. Pretreated vermiculite powder was mixed with a 10wt% humic acid solution, with a solid-liquid ratio of 1:5 (kg / L). Then, a 1.0wt% proline solution was added, with the amount of proline solution added being 5% of the volume of the humic acid solution. The mixture was stirred and adsorbed at 40℃ for 4 hours, and then vacuum dried at 60℃ for 8 hours to obtain modified vermiculite powder.

[0040] The photothermal conversion microspheres were prepared by the following method: Fresh cuttlefish ink sacs were rinsed with deionized water, the ink sacs were cut open, and the ink was collected. The ink was frozen at -80℃ for 20 hours, then pulverized and passed through an 80-mesh sieve, and subsequently dried in a vacuum drying oven at 60℃ for 10 hours to obtain cuttlefish ink powder. The cuttlefish ink powder was mixed with a 4wt% sodium alginate solution at a mass-to-volume ratio of 1:6 (kg / L), and homogenized at 12000 rpm for 5 minutes to form a uniform slurry. This slurry was then processed... The microsphere cores were prepared by spray drying, with the inlet air temperature controlled at 160℃, the outlet air temperature controlled at 85℃, and the feed flow rate adjusted to 10mL / min. Subsequently, a fluidized bed coating device was used, with a 2.0wt% chitosan acetic acid solution and a 3.0wt% calcium chloride aqueous solution as coating materials. The coatings were alternately sprayed 5 times at a fluidization temperature of 50℃, and allowed to stand for 10 minutes after each spraying. Finally, the microspheres were fluidized and dried at 55℃ for 30 minutes to obtain photothermal conversion microspheres.

[0041] Example 3

[0042] A bio-organic fertilizer comprises the following raw materials in parts by weight: 12.5 parts rice husk, 10 parts peanut shell, 12.5 parts sugarcane bagasse, 18 parts straw, 22.5 parts poultry and livestock manure, 7.5 parts pond mud, 4 parts wood ash, 8 parts oilseed meal, 7.5 parts ammonium phosphate, 3.5 parts low-temperature compound microbial agent, 4.5 parts seaweed oligosaccharide, 8 parts modified vermiculite powder, and 15 parts photothermal conversion microspheres; wherein the low-temperature compound microbial agent is composed of cold-resistant Bacillus and low-temperature Pseudomonas in a mass ratio of 4:2, and the viable count of cold-resistant Bacillus is ≥3.0×10⁻⁶. 8 CFU / g, viable count of *Pseudomonas pyrophila* ≥ 2.0 × 10⁻⁶ 8 CFU / g. The molecular weight of the seaweed oligosaccharide is 800 Da. The ammonium phosphate is a 1:1 mixture of ammonium dihydrogen phosphate and diammonium hydrogen phosphate, and the oil meal is a 1:1 combination of rapeseed meal and tea seed meal.

[0043] The modified vermiculite powder was obtained through a two-step method of hydrochloric acid pretreatment and humic acid-proline composite modification, and was prepared by the following method:

[0044] A. The raw vermiculite ore is crushed to a particle size of 1.3 mm to obtain vermiculite powder. The vermiculite powder is soaked in a 12 wt% hydrochloric acid solution with a solid-liquid ratio of 1:6.5 kg / L between the vermiculite powder and the hydrochloric acid solution. The mixture is then treated in a water bath at 82°C for 3 hours, washed with water until neutral, and dried at 70°C for 5 hours to obtain pretreated vermiculite powder.

[0045] B. Pretreated vermiculite powder was mixed with an 8 wt% humic acid solution, with a solid-liquid ratio of 1:4 (kg / L). Then, a 0.8 wt% proline solution was added, with the amount of proline solution added being 3.5% of the volume of the humic acid solution. The mixture was stirred and adsorbed at 35°C for 5 hours, and then vacuum dried at 55°C for 10 hours to obtain modified vermiculite powder.

[0046] The photothermal conversion microspheres were prepared by the following method: Fresh cuttlefish ink sacs were rinsed with deionized water, the ink sacs were cut open, and the ink was collected. The ink was frozen at -70℃ for 25 hours, then pulverized and passed through a 60-mesh sieve, and subsequently dried in a vacuum drying oven at 55℃ for 12.5 hours to obtain cuttlefish ink powder. The cuttlefish ink powder was mixed with a 3wt% sodium alginate solution at a mass-to-volume ratio of 1:5 (kg / L), and homogenized at 10000 rpm for 10 minutes to form a uniform slurry. This slurry was then... The microsphere cores were prepared by spray drying, with the inlet air temperature controlled at 150℃, the outlet air temperature controlled at 78℃, and the feed flow rate adjusted to 7.5mL / min. Subsequently, a fluidized bed coating device was used, with a 1.5wt% chitosan acetic acid solution and a 2.5wt% calcium chloride aqueous solution as coating materials. The coatings were alternately sprayed four times at a fluidization temperature of 45℃, and allowed to stand for 7.5min after each spraying. Finally, the microspheres were fluidized and dried at 50℃ for 45min to obtain photothermal conversion microspheres.

[0047] The method for preparing a bio-organic fertilizer as described in Examples 1-3 includes the following steps:

[0048] S1. Rice husks, peanut shells, sugarcane bagasse, and straw are crushed to a particle size of 2 mm to obtain a mixture of plant materials. 0.2% by mass of a compound enzyme is added to the mixture of plant materials, the moisture content is adjusted to 45%, and enzymatic hydrolysis is carried out in a sealed environment at 48℃ for 115 h to obtain pretreated raw materials. The compound enzyme consists of β-glucanase, β-glucosidase, and xylanase in a mass ratio of 7.0:1.8:1.2, with β-glucanase activity of 12000 U / g, β-glucosidase activity of 6000 U / g, and xylanase activity of 9000 U / g.

[0049] S2. Mix the pretreated raw materials with poultry and livestock manure, pond mud, and oilseed meal, adjust the moisture content to 45%, and adopt an anaerobic-aerobic alternating fermentation mode: first, perform anaerobic fermentation in a closed system at 18℃ for 6 days, then turn the pile and switch to aerobic fermentation, control the pile temperature at 38℃, adjust the pH value to 7.0, and perform aerobic fermentation for 3 days, and then start the next round of anaerobic fermentation, alternating for 4 cycles; after the fermentation is completed, dry the material at 42℃ for 24 hours to obtain fermented material;

[0050] S3. Mix fermentation material, ammonium phosphate, wood ash, low-temperature compound microbial agent, seaweed oligosaccharide, modified vermiculite powder, and photothermal conversion microspheres. Stir at 60 rpm for 30 min, then dry at 37℃ for 13 h. Finally, pulverize and pass through a 30-mesh sieve to obtain bio-organic fertilizer.

[0051] Example 4

[0052] Compared with Example 3, the difference in this embodiment is that the method for preparing a bio-organic fertilizer includes the following steps:

[0053] S1. Rice husks, peanut shells, sugarcane bagasse, and straw are crushed to a particle size of 3 mm to obtain a mixture of plant materials. 0.3% of a compound enzyme is added to the mixture, the moisture content is adjusted to 50%, and the mixture is enzymatically hydrolyzed in a sealed container at 50°C for 12 h to obtain pretreated raw materials. The compound enzyme consists of β-glucanase, β-glucosidase, and xylanase in a mass ratio of 8.0:2.0:1.5, with β-glucanase activity of 15000 U / g, β-glucosidase activity of 8000 U / g, and xylanase activity of 10000 U / g.

[0054] S2. Mix the pretreated raw materials with poultry and livestock manure, pond mud, and oilseed meal, adjust the moisture content to 50%, and adopt an anaerobic-aerobic alternating fermentation mode: first, perform anaerobic fermentation in a closed system at 20℃ for 5 days, then turn the pile and switch to aerobic fermentation, control the pile temperature at 40℃, adjust the pH value to 7.5, and perform aerobic fermentation for 3 days, and then start the next round of anaerobic fermentation, alternating for 3 cycles; after the fermentation is completed, dry the material at 45℃ for 22 hours to obtain fermented material;

[0055] S3. Mix fermentation material, ammonium phosphate, wood ash, low-temperature compound microbial agent, seaweed oligosaccharide, modified vermiculite powder, and photothermal conversion microspheres. Stir at 150 rpm for 20 min, then dry at 40℃ for 10 h. Finally, pulverize and pass through a 40-mesh sieve to obtain bio-organic fertilizer.

[0056] Example 5

[0057] Compared with Example 3, the difference in this embodiment is that the method for preparing a bio-organic fertilizer includes the following steps:

[0058] S1. Rice husks, peanut shells, sugarcane bagasse, and straw are crushed to a particle size of 1 mm to obtain a mixture of plant materials. 0.1% of a compound enzyme is added to the mixture to adjust the moisture content to 40%. The mixture is then enzymatically hydrolyzed in a sealed environment at 45°C for 18 h to obtain pretreated raw materials. The compound enzyme consists of β-glucanase, β-glucosidase, and xylanase in a mass ratio of 6.0:1.5:1.0. The β-glucanase activity is 10000 U / g, the β-glucosidase activity is 5000 U / g, and the xylanase activity is 8000 U / g.

[0059] S2. Mix the pretreated raw materials with poultry and livestock manure, pond mud, and oilseed meal, adjust the moisture content to 40%, and adopt an anaerobic-aerobic alternating fermentation mode: first, perform anaerobic fermentation in a closed system at 15℃ for 7 days, then turn the pile and switch to aerobic fermentation, control the pile temperature at 35℃, adjust the pH value to 6.5, and perform aerobic fermentation for 4 days, and then start the next round of anaerobic fermentation, alternating for 4 cycles; after the fermentation is completed, dry the material at 40℃ for 26 hours to obtain fermented material;

[0060] S3. Mix fermentation material, ammonium phosphate, wood ash, low-temperature compound microbial agent, seaweed oligosaccharide, modified vermiculite powder, and photothermal conversion microspheres. Stir at 60 rpm for 30 min, then dry at 350℃ for 15 h. Finally, pulverize and pass through a 20-mesh sieve to obtain bio-organic fertilizer.

[0061] Comparative Example 1

[0062] The difference between this comparative example and Example 3 is that commercially available bio-organic fertilizer is used instead of the bio-organic fertilizer of this invention.

[0063] Comparative Example 2

[0064] The difference between this comparative example and Example 3 is that an equal amount of mesothermic Bacillus subtilis was used instead of the low-temperature compound bacterial agent.

[0065] Comparative Example 3

[0066] The difference between this comparative example and Example 3 is that an equal amount of unmodified vermiculite powder was used instead of modified vermiculite powder.

[0067] Comparative Example 4

[0068] The difference between this comparative example and Example 3 is that the raw materials do not contain ammonium phosphate.

[0069] Comparative Example 5

[0070] The difference between this comparative example and Example 3 is that the raw materials do not contain photothermal conversion microspheres.

[0071] Performance testing

[0072] I. Organic matter content detection

[0073] Referring to GB / T3597-2002 "Determination of Total Organic Matter in Organic Fertilizers", the potassium dichromate oxidation-external heating method was adopted.

[0074] Weigh 0.5g of each of the bio-organic fertilizer samples prepared in Examples 1-5 and Comparative Examples 1-5 (passed through a 2mm sieve) and place them in a 500mL Erlenmeyer flask. Add 10mL of 0.8mol / L potassium dichromate solution and 20mL of concentrated sulfuric acid. Shake well and heat in an electric sand bath to 175℃, maintaining boiling for 5 minutes. After cooling, transfer to a 250mL beaker, add water to 100mL, add 3 drops of o-phenanthroline indicator, and titrate with 0.2mol / L ferrous sulfate solution until the solution changes from orange-red to blue-green, which is the endpoint. Simultaneously, perform a blank test. Calculate the organic matter content based on the titration difference: Organic matter (%) = (Volume of ferrous sulfate consumed in blank test - Volume of ferrous sulfate consumed in sample test) × Ferrous sulfate concentration × 0.003 × 1.724 × 100 / Sample mass. Perform the test three times and record the average value in Table 1.

[0075] II. Methods for detecting microbial activity at 0℃

[0076] Using the fluorescein diacetate (FDA) hydrolysis method:

[0077] Weigh 5g of the bio-organic fertilizer samples prepared in Examples 1-5 and Comparative Examples 1-5 respectively, add 50mL of sterile water, shake for 30min, filter, and take 10mL of filtrate into a centrifuge tube; add 0.5mL of 0.1% FDA solution, and react in a constant temperature incubator at 0℃ in the dark for 12h; add 10mL of acetone to stop the reaction, centrifuge at 3000r / min for 10min, and take the supernatant to measure the absorbance at a wavelength of 490nm; plot a standard curve with fluorescein standard solution, and calculate the FDA hydrolysis rate (μg / g·h) based on the absorbance to characterize microbial activity, with higher values ​​indicating stronger activity. Measure three times, and record the average value in Table 1.

[0078] III. Nitrogen mineralization rate detection at 0℃

[0079] Weigh 10g of the bio-organic fertilizer samples prepared by Examples 1-5 and Comparative Examples 1-5 (passed through a 2mm sieve) and mix them thoroughly with 200g of air-dried soil (passed through a 2mm sieve) to obtain a mixed sample. Put the mixed sample into a 500mL Erlenmeyer flask and adjust the moisture content to 60% of the field capacity. At the same time, a blank control (soil only) is set up.

[0080] After sealing the conical flask, place it in a 0℃ constant temperature incubator and incubate for 30 days, replenishing water regularly to maintain stable moisture content. Take mixed samples before and after incubation, extract with 2 mol / L KCl solution (soil-to-solution ratio 1:10), shake for 30 min, filter, and determine the ammonium nitrogen and nitrate nitrogen content in the filtrate using a continuous flow analyzer. The sum of these two is the available nitrogen. Calculate the mineralization rate: Nitrogen mineralization rate (%) = (available nitrogen in the sample after incubation - available nitrogen in the sample before incubation - change in available nitrogen in the blank control) / total fertilizer nitrogen content × 100. Perform the test three times, and record the average value in Table 1.

[0081] Table 1

[0082] Organic matter content (%) FDA hydrolysis rate (μg / g-h) Nitrogen mineralization rate (%) Example 1 51.8 17.8 14.5 Example 2 52.3 17.5 14.7 Example 3 53.0 18.2 15.3 Example 4 52.1 17.3 14.9 Example 5 51.5 17.5 14.8 Comparative Example 1 52.8 7.0 6.1 Comparative Example 2 52.6 7.8 7.5 Comparative Example 3 50.5 9.5 9.6 Comparative Example 4 56.7 12.7 8.3 Comparative Example 5 50.2 7.5 6.9

[0083] As shown in Table 1, the organic matter content of Examples 1-5 was 51.5%-53.0%, comparable to that of the commercially available Comparative Example 1. However, the FDA hydrolysis rate of Examples 1-5 was 17.5-18.2 μg / g·h, significantly higher than the 7.0 μg / g·h of Comparative Example 1 and the 7.8 μg / g·h of Comparative Example 2. The main reason is that Examples 1-5 used a low-temperature compound microbial agent composed of cold-resistant Bacillus and low-temperature Pseudomonas, which exhibits better metabolic capacity under low-temperature conditions. Combined with vermiculite powder modified with humic acid-proline, it provides a carbon source and low-temperature protection for the microorganisms, further enhancing cell membrane stability. The commercially available bio-organic fertilizer in Comparative Example 1 used room-temperature-adapted strains, whose activity was significantly inhibited at soil temperatures <10℃, resulting in a substantial decrease in the decomposition rate of organic matter in the fertilizer. Comparative Example 2 used mesophilic Bacillus subtilis instead of the low-temperature microbial agent, resulting in a significant decrease in metabolism at low temperatures; therefore, the FDA hydrolysis rate also decreased significantly. It is evident that the low-temperature microbial community of the present invention plays a crucial role under low-temperature conditions, thereby ensuring crop growth performance under such conditions. Furthermore, the photothermal conversion microspheres in the bio-organic fertilizers of Examples 1-5 can efficiently absorb sunlight and convert it into heat energy, forming a localized, mild "heat island effect" around the microbial agent, raising the microenvironment temperature by 1-3°C, thereby significantly accelerating its reproduction and the decomposition rate of organic matter.

[0084] The nitrogen mineralization rate of Examples 1-5 was 14.5%-15.3%, approximately 2.5 times that of Comparative Example 1, and significantly higher than that of Comparative Examples 3, 4, and 5. This is attributed to the synergistic effect of the "low-temperature bacterial agent + modified vermiculite powder + ammonium phosphate + photothermal conversion microspheres" of the present invention. Specifically, the modified vermiculite powder adsorbs and slowly releases nutrients, preventing loss and providing colonization sites and a warm environment for the low-temperature bacteria; the low-temperature bacterial agent accelerates the decomposition of organic matter and promotes nitrogen conversion; ammonium phosphate supplements readily available nitrogen and alleviates lag; and the photothermal conversion microspheres absorb sunlight and convert it into heat energy, increasing the local microenvironment temperature and thus enhancing the metabolic performance of the low-temperature bacteria. The photothermal conversion microspheres, by increasing the local microenvironment temperature, also promote crop root growth, thereby promoting early crop development.

[0085] The photothermal conversion microspheres in this invention are mainly made from cuttlefish ink powder. The eumelanin in cuttlefish ink powder has a conjugated system in its molecular structure that can absorb a very wide range of spectra from ultraviolet to near-infrared. When the cuttlefish melanin nanoparticles absorb photons, they convert them into lattice heat energy through molecular vibration and rotation, thereby raising the temperature of the microspheres themselves and their surrounding local environment. Furthermore, cuttlefish ink powder is rich in nitrogen, carbon, and various trace elements. Its slow degradation in soil further replenishes the soil with nutrients, providing natural nutrition for soil microorganisms and crops.

[0086] 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 within the protection scope of the present invention.

Claims

1. A bio-organic fertilizer, characterized in that, The method comprises the following raw materials by weight: rice husk 10-15 parts, peanut shell 8-12 parts, sugarcane residue 10-15 parts, straw 15-20 parts, poultry manure 20-25 parts, pond mud 5-10 parts, wood ash 3-5 parts, oil meal 5-10 parts, ammonium phosphate 5-10 parts, low-temperature compound microbial agent 2-5 parts, seaweed oligosaccharide 3-6 parts, modified vermiculite powder 5-10 parts, and 10-20 parts of light-heat conversion microspheres. The modified vermiculite powder is obtained by a two-step method of hydrochloric acid pretreatment and humic acid-proline compound modification.

2. The bio-organic fertilizer according to claim 1, characterized in that, The low-temperature compound microbial agent is compounded by cold-resistant bacillus and low-temperature pseudomonas in a mass ratio of (3-5) :(1.8-2.2), wherein the viable count of the cold-resistant bacillus is greater than or equal to 3.0*10 8 CFU / g, and the viable count of the low-temperature pseudomonas is greater than or equal to 2.0*10 8 CFU / g.

3. The bio-organic fertilizer according to claim 1, characterized in that, The modified vermiculite powder is prepared by the following method: A. The vermiculite ore is crushed to obtain vermiculite powder, the vermiculite powder is soaked in a hydrochloric acid solution, treated in a water bath at 80-85℃ for 2-4h, then washed with water to neutral, and dried at 60-80℃ for 4-6h to obtain pretreated vermiculite powder; B. The pretreated vermiculite powder is mixed with a humic acid solution, then a proline solution is added, stirred and adsorbed at 30-40℃ for 4-6h, and then vacuum dried at 50-60℃ for 8-12h to obtain modified vermiculite powder.

4. The bio-organic fertilizer according to claim 3, characterized in that, In step A, the concentration of the hydrochloric acid solution is 10-15wt%, the solid-liquid ratio Kg / L of the vermiculite powder to the hydrochloric acid solution is 1:(5-8), and the particle size of the vermiculite powder is 0.5-2mm.

5. The bio-organic fertilizer according to claim 3, characterized in that, In step B, the concentration of the humic acid solution is 5-10wt%, the concentration of the proline solution is 0.3-1.0wt%, the solid-liquid ratio Kg / L of the pretreated vermiculite powder to the humic acid solution is 1:(3-5), and the addition amount of the proline solution is 2-5% of the volume of the humic acid solution.

6. The bio-organic fertilizer according to claim 1, wherein the bio-organic fertilizer is characterized by, The molecular weight of the seaweed oligosaccharide is 500-1000Da.

7. The bio-organic fertilizer according to claim 1, wherein the bio-organic fertilizer is characterized by, The ammonium phosphate is a 1:1 compound of ammonium dihydrogen phosphate and diammonium hydrogen phosphate, and the oil meal is one or a combination of several of rapeseed meal, peanut meal, sesame meal, and tea seed meal.

8. The bio-organic fertilizer according to claim 1, wherein the bio-organic fertilizer is characterized by, The light-heat conversion microspheres are prepared by the following method: fresh cuttlefish ink sacs are washed with deionized water, cut open, and the ink is collected, frozen at-60 to-80℃ for 20-30h, then crushed through a 40-80 mesh screen, and then placed in a vacuum drying oven at 50-60℃ for 10-15h to obtain cuttlefish ink powder; the cuttlefish ink powder is mixed with a 2-4wt% sodium alginate solution at a mass / volume ratio Kg / L of 1:4-6, homogenized at a speed of 8000-12000rpm for 5-15min to form a uniform slurry, then the microsphere core is prepared by spray drying, with the spray drying inlet temperature controlled at 140-160℃, the outlet temperature controlled at 70-85℃, and the feed flow rate adjusted at 5-10mL / min; then using a fluidized bed coating device, a 1.0-2.0wt% chitosan acetic acid solution and a 2.0-3.0wt% calcium chloride aqueous solution are used as coating materials, and are alternately sprayed 3-5 times at a fluidization temperature of 40-50℃, with 5-10min of standing and penetration after each spraying, and finally fluidized and dried at 45-55℃ for 30-60min to obtain light-heat conversion microspheres.

9. The method for preparing a bio-organic fertilizer according to any one of claims 1-8, characterized in that, The method comprises the following steps: S1, rice husk, peanut shell, bagasse, straw are crushed to a particle size of ≤3mm to obtain a plant raw material mixture; 0.1-0.3% of a composite enzyme is added to the plant raw material mixture, the moisture content is adjusted to 40-50%, and the mixture is closed-enzyme hydrolyzed at 45-50°C for 12-18h to obtain pretreated raw material; S2, the pretreated raw material is mixed with poultry manure, pond mud, oil meal, the moisture content is adjusted to 40-50%, and an anaerobic-aerobic alternating fermentation mode is used: first closed anaerobic fermentation at 15-20°C for 5-7 days, then turn to aerobic fermentation by turning the pile, control the pile temperature ≤40°C, adjust the pH value to 6.5-7.5, aerobic fermentation for 3-4 days, then re-perform the next round of anaerobic fermentation, alternating for 3-4 cycles; after fermentation, the material is dried at 40-45°C for 22-26h to obtain fermented material; S3, the fermented material, ammonium phosphate, wood ash, low-temperature composite microbial agent, seaweed oligosaccharide, modified vermiculite powder, and light-heat conversion microspheres are mixed, stirred at 60-150rpm for 20-30min, then dried at 35-40°C for 10-15h, then crushed through a 20-40 mesh sieve to obtain a bio-organic fertilizer.

10. The method of claim 9, wherein the bio-organic fertilizer is prepared by the steps of: The composite enzyme in S1 is composed of β-glucanase, β-glucosidase, and xylanase with a mass ratio of (6.0-8.0):(1.5-2.0):(1.0-1.5), the β-glucanase enzyme activity is ≥10000U / g, the β-glucosidase enzyme activity is ≥5000U / g, and the xylanase enzyme activity is ≥8000U / g. ​