Environment-friendly bio-organic fertilizer and preparation method thereof

Abstract

The application belongs to the technical field of microbial fertilizer, and particularly relates to an environment-friendly biological organic fertilizer and a preparation method thereof.The environment-friendly biological organic fertilizer comprises the following raw materials in parts by weight: 70-90 parts of fermented organic matter, 8-13 parts of microbial agent and 10-15 parts of coated suspension.The test results show that after the environment-friendly biological organic fertilizer is applied to soil, the growth of crops can be effectively promoted, the yield of crops is improved, the nutritional quality and edible safety of crop fruits are significantly improved, and the environment-friendly biological organic fertilizer has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of microbial fertilizer technology, specifically relating to an environmentally friendly bio-organic fertilizer and its preparation method. Background Technology

[0002] Bio-organic fertilizer is a type of fertilizer made primarily from animal manure and agricultural byproduct residues, fermented and decomposed by specific functional microorganisms. It combines the effects of both microbial fertilizer and organic fertilizer. It not only provides crops with inorganic nutrients such as nitrogen, phosphorus, and potassium, but is also rich in organic matter such as amino acids, proteins, sugars, and various trace elements, and contains one or more functional microorganisms. Applying bio-organic fertilizer can improve soil structure, regulate microbial communities, increase nutrient utilization, and reduce soil-borne diseases, making it an important technical means for developing green and sustainable agriculture.

[0003] However, conventional bio-organic fertilizers still face two major challenges in practical applications, which restrict their full effectiveness: First, the problem of controlled nutrient release. The nutrient release rate of traditional organic fertilizers does not match the crop demand curve well, which can easily lead to early loss and insufficient supply in the later stage. Second, the problem of maintaining the activity of functional microorganisms. Microorganisms are easily inactivated in processing, storage and complex soil environments, making their colonization and functional expression unstable.

[0004] Therefore, industry research focuses on how to effectively control the nutrient release rate and significantly enhance and stabilize the activity of functional microorganisms while realizing the resource utilization of agricultural waste. Based on the above objectives, this invention provides an environmentally friendly bio-organic fertilizer with both highly efficient slow-release and potent microbial functions, and its preparation method. Summary of the Invention

[0005] One of the objectives of this invention is to provide an environmentally friendly bio-organic fertilizer.

[0006] The second objective of this invention is to provide a method for preparing an environmentally friendly bio-organic fertilizer.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An environmentally friendly bio-organic fertilizer comprises the following raw materials in parts by weight: 70-90 parts fermented organic matter, 8-13 parts microbial inoculant, and 10-15 parts coated suspension.

[0008] The above-described method for preparing an environmentally friendly bio-organic fertilizer specifically includes the following steps: (1) Activate Bacillus subtilis to obtain Bacillus subtilis bacterial solution; (2) The Bacillus subtilis bacterial solution obtained in step (1) is inoculated into a fermentation medium and fermented to obtain a fermentation broth. After spray drying, the microbial agent is obtained. (3) Mix the microbial agent obtained in step (2) with the fermented organic matter, crush it, pass it through an 80-100 mesh sieve, and make it into granules; spray the coated suspension evenly on the surface of the granules, dry it, and you will get an environmentally friendly bio-organic fertilizer.

[0009] Furthermore, the preparation method of the coated suspension specifically includes the following steps: 1) Under a nitrogen atmosphere, corn stalk powder is heated to 350-500℃ and calcined for 2-4 hours, then cooled to room temperature to obtain biochar; the biochar is added to nitric acid solution for oxidation for 3-5 hours, centrifuged, washed, and dried to obtain oxidized biochar. 2) The oxidized biochar prepared in step 1) is ultrasonically dispersed in deionized water to obtain an oxidized biochar suspension. Alkali solution is added dropwise to adjust its pH value to 8-9, limonene epoxide is added, and the mixture is stirred for 6-8 h. After washing and drying, limonene epoxide modified biochar is obtained. 3) The limonene epoxide-modified biochar was ultrasonically dispersed in deionized water to obtain a coated suspension.

[0010] Furthermore, in step 1), the nitric acid content in the nitric acid solution is 1-3 mol / L; the feed ratio of biochar to nitric acid solution is (10-15) g: 100 mL.

[0011] Further, in step 2), the ratio of oxidized biochar to deionized water is 1 g: 200-400 mL; the concentration of the alkali solution is 12-16 wt%; the mass of the limonene epoxide is 10-15 wt% of the mass of the oxidized biochar; and the mixing temperature is 70-80℃.

[0012] Furthermore, the ultrasonic dispersion time in step 3) is 30-60 min; the concentration of the coated suspension is 4-6 wt%.

[0013] Further, the specific steps for activating Bacillus subtilis in step (1) are as follows: Bacillus subtilis is inoculated into LB medium at an inoculation rate of 2-4 v / v %, and cultured at 30-37℃ for 16-24 h to obtain Bacillus subtilis bacterial suspension; the effective viable count of the Bacillus subtilis bacterial suspension is ≥1.0×10⁻⁶. 8 CFU / mL.

[0014] Further, in step (2), the inoculum amount is 3-5 v / v %; the fermentation temperature is 30-37℃; the fermentation time is 48-72h; the concentration of sucrose in the fermentation medium is 15-18g / L, the concentration of D-glucosamine potassium sulfate is 2-4g / L, the concentration of peptone is 10-12g / L, the concentration of yeast extract is 5-7g / L, the concentration of carotene is 3-5g / L, the concentration of MgSO4·7H2O is 0.4-1g / L, the concentration of MnSO4·H2O is 3-5g / L, and the concentration of CaCl2 is 25-30mg / L.

[0015] Furthermore, the method for preparing the fermented organic matter specifically includes the following steps: S1. Poultry and livestock manure and corn stalks are dried separately by ventilation, crushed, and passed through an 80-100 mesh sieve to obtain the material; S2. Put the material obtained in step S1 into the fermentation tank and mix it evenly. Add water to make the water content of the system 50-60wt%. Then add EM bacterial solution and seal the fermentation tank with plastic film. Turn the fermentation pile once every 2-3 days until the material is completely decomposed. S3 After the material has decomposed, it is dried until the moisture content is 20-30 wt%, which yields fermented organic matter.

[0016] Furthermore, the weight ratio of poultry and livestock manure to corn stalks is 1:(1-1.5); the amount of EM bacterial solution added is 0.3-0.5 wt% of the total weight of poultry and livestock manure and corn stalks.

[0017] Compared with the prior art, the main advantages of the present invention are as follows: 1. Constructing a Highly Efficient Slow-Release System: Isooctyl ester-modified biochar was used as a slow-release coating agent. First, limonene epoxide was grafted onto the biochar, introducing a terpene-based hydrophobic framework onto its surface, forming a directionally aligned hydrophobic barrier. This barrier effectively delays premature nutrient dissolution and loss through both physical barrier and ion exchange, achieving controlled nutrient release and significantly improving fertilizer utilization.

[0018] 2. Enhanced Microbial Function: By adding D-glucosamine potassium sulfate to the fermentation medium, this component combines the functions of a highly efficient microbial growth promoter and a high-quality carbon and nitrogen source. It can significantly enhance the activity and proliferation capacity of beneficial bacteria such as Bacillus subtilis, ensuring that they can exert their multiple functions such as growth promotion and disease resistance in the soil for a long time and with high efficiency.

[0019] 3. By optimizing key components and structure, the slow-release performance and microbial activity of the fertilizer are significantly improved. After this environmentally friendly bio-organic fertilizer is applied to the soil, it can effectively promote crop growth, increase crop yield, and significantly improve the nutritional quality and food safety of fruits, thus achieving the goal of resource utilization and green environmental protection of agricultural waste.

[0020] 4. This preparation method uses agricultural waste such as pig manure, corn stalk biochar, and peanut stalks as main raw materials. It not only achieves resource utilization of waste and reduces environmental burden, but the entire system is also completely biodegradable with no harmful residues. This technology avoids the environmental pollution problems caused by chemical additives at the source, achieving an organic unity between fertilizer efficiency enhancement and ecological environmental protection. Attached Figure Description

[0021] Figure 1 This is a scanning electron microscope image of the limonene epoxide-modified biochar prepared in Example 1 of the present invention; Figure 2 The graph shows the effect of different environmentally friendly bio-organic fertilizers on nitrogen release rate. Detailed Implementation

[0022] The technical solution of the present invention will be further described below with reference to specific embodiments. However, those skilled in the art should understand that the following embodiments are only for illustrating the present invention and should not be regarded as limiting the present invention. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the reagents or instruments used are all conventional products obtained through commercial channels.

[0023] The Bacillus subtilis used in this invention has the accession number CGMCC No. 8340 and was purchased from the China General Microbiological Culture Collection Center (CGMCC).

[0024] Example 1 An environmentally friendly bio-organic fertilizer comprises the following raw materials in parts by weight: 80 parts fermented organic matter, 10 parts microbial inoculant, and 12 parts coated suspension.

[0025] The method for preparing fermented organic matter according to the present invention specifically includes the following steps: S1. Poultry and livestock manure and corn stalks are dried separately by ventilation, crushed, and passed through a 90-mesh sieve to obtain the material; the weight ratio of poultry and livestock manure to corn stalks is 1:1.2.

[0026] S2. The material obtained in step S1 is placed in the fermentation tank and mixed evenly. Water is added to make the water content of the system 55wt%. Then EM bacterial solution is added, and the fermentation tank is sealed with plastic film. The fermentation pile is turned over once every 2 days until the material is completely decomposed. The amount of EM bacterial solution added is 0.4wt% of the total weight of poultry and livestock manure and corn stalks.

[0027] S3 After the material has decomposed, it is dried until the moisture content is 25wt% to obtain fermented organic matter.

[0028] The method for preparing the coated suspension of the present invention specifically includes the following steps: 1) Under a nitrogen atmosphere, corn stalk powder was heated to 420℃ and calcined for 3 h, then cooled to room temperature to obtain biochar; the biochar was added to a nitric acid solution with a nitric acid content of 2 mol / L and oxidized for 4 h, centrifuged, washed, and dried to obtain oxidized biochar; the feeding ratio of biochar to nitric acid solution was 12 g: 100 mL.

[0029] 2) The oxidized biochar prepared in step 1) was ultrasonically dispersed in deionized water at a ratio of 1 g to 300 mL to obtain an oxidized biochar suspension. A 14 wt% alkaline solution was added dropwise to adjust the pH to 8. Limonene epoxide was then added, and the mixture was stirred at 75°C for 7 h. The mass of the limonene epoxide was 12 wt% of the mass of the oxidized biochar in the suspension. After washing and drying, limonene epoxide-modified biochar was obtained. The microstructure of the limonene epoxide-modified biochar was characterized using scanning electron microscopy, and the results are as follows: Figure 1 As shown.

[0030] 3) The limonene epoxide-modified biochar was ultrasonically dispersed in deionized water for 45 min to obtain a coated suspension; the concentration of the coated suspension was 5% wt.

[0031] A method for preparing an environmentally friendly bio-organic fertilizer specifically includes the following steps: (1) Bacillus subtilis was inoculated into LB medium at an inoculation rate of 3 v / v % and cultured at 35°C for 20 h to obtain Bacillus subtilis bacterial suspension; the effective viable count of the Bacillus subtilis bacterial suspension was ≥1.0×10⁻⁶. 8 CFU / mL.

[0032] (2) The Bacillus subtilis culture obtained in step (1) was inoculated into the fermentation medium at an inoculation amount of 4 v / v % and fermented at 35℃ for 60 h to obtain the fermentation broth. After spray drying, the microbial agent was obtained. The fermentation medium contained 16 g / L sucrose, 3 g / L D-glucosamine sulfate potassium salt, 11 g / L peptone, 6 g / L yeast extract, 4 g / L carotene, 0.7 g / L MgSO4·7H2O, 4 g / L MnSO4·H2O, and 27 mg / L CaCl2.

[0033] (3) Weigh out the microbial agent and fermented organic matter according to the weight proportions, crush it, pass it through a 90-mesh sieve, and make it into granules; spray the coated suspension evenly on the surface of the granules, dry it, and you will get an environmentally friendly bio-organic fertilizer.

[0034] Example 2 An environmentally friendly bio-organic fertilizer comprises the following raw materials in parts by weight: 70 parts fermented organic matter, 8 parts microbial inoculant, and 10 parts coated suspension.

[0035] The method for preparing fermented organic matter according to the present invention specifically includes the following steps: S1. Poultry and livestock manure and corn stalks are ventilated and dried separately, crushed, and passed through an 80-mesh sieve to obtain the material; the weight ratio of poultry and livestock manure to corn stalks is 1:1.

[0036] S2. The material obtained in step S1 is placed in the fermentation tank and mixed evenly. Water is added to make the water content of the system 50wt%. Then EM bacterial solution is added, and the fermentation tank is sealed with plastic film. The fermentation pile is turned over once every 2 days until the material is completely decomposed. The amount of EM bacterial solution added is 0.3wt% of the total weight of poultry and livestock manure and corn stalks.

[0037] S3 After the material has decomposed, it is dried until the moisture content is 20wt% to obtain fermented organic matter.

[0038] The method for preparing the coated suspension of the present invention specifically includes the following steps: 1) Under a nitrogen atmosphere, corn stalk powder was heated to 350℃ and calcined for 2 h, then cooled to room temperature to obtain biochar; the biochar was added to a nitric acid solution with a nitric acid content of 1 mol / L and oxidized for 3 h, centrifuged, washed, and dried to obtain oxidized biochar; the feeding ratio of biochar to nitric acid solution was 10 g: 100 mL.

[0039] 2) The oxidized biochar prepared in step 1) is ultrasonically dispersed in deionized water at a ratio of 1 g to 200 mL to obtain an oxidized biochar suspension. A 12 wt% alkaline solution is added dropwise to adjust the pH to 8. Limonene epoxide is added and the mixture is stirred at 70°C for 6 h. The mass of limonene epoxide is 10 wt% of the mass of the oxidized biochar in the oxidized biochar suspension. After washing and drying, limonene epoxide-modified biochar is obtained.

[0040] 3) The limonene epoxide-modified biochar was ultrasonically dispersed in deionized water for 30 min to obtain a coated suspension; the concentration of the coated suspension was 4% wt.

[0041] A method for preparing an environmentally friendly bio-organic fertilizer specifically includes the following steps: (1) Bacillus subtilis was inoculated into LB medium at an inoculation rate of 2 v / v % and cultured at 30°C for 16 h to obtain Bacillus subtilis bacterial suspension; the effective viable count of the Bacillus subtilis bacterial suspension was ≥1.0×10⁻⁶. 8 CFU / mL.

[0042] (2) The Bacillus subtilis culture obtained in step (1) is inoculated into the fermentation medium at an inoculation amount of 3v / v % and fermented at 30℃ for 48h to obtain the fermentation broth. After spray drying, the microbial agent is obtained. The fermentation medium contains 15g / L sucrose, 2g / L D-glucosamine sulfate potassium salt, 10g / L peptone, 5g / L yeast extract, 3g / L carotene, 0.4g / L MgSO4·7H2O, 3g / L MnSO4·H2O, and 25mg / L CaCl2.

[0043] (3) Weigh out the microbial agent and fermented organic matter according to the weight proportions, crush it, pass it through an 80-mesh sieve, and make it into granules; spray the coated suspension evenly on the surface of the granules, dry it, and you will get an environmentally friendly bio-organic fertilizer.

[0044] Example 3 An environmentally friendly bio-organic fertilizer comprises the following raw materials in parts by weight: 90 parts fermented organic matter, 13 parts microbial inoculant, and 15 parts coated suspension.

[0045] The method for preparing fermented organic matter according to the present invention specifically includes the following steps: S1. Poultry and livestock manure and corn stalks are dried separately by ventilation, crushed, and passed through a 100-mesh sieve to obtain the material; the weight ratio of poultry and livestock manure to corn stalks is 1:1.5.

[0046] S2. The material obtained in step S1 is placed in the fermentation tank and mixed evenly. Water is added to make the water content of the system 60wt%. Then EM bacterial solution is added, and the fermentation tank is sealed with plastic film. The fermentation pile is turned over once every 2 days until the material is completely decomposed. The amount of EM bacterial solution added is 0.5wt% of the total weight of poultry and livestock manure and corn stalks.

[0047] S3 After the material has decomposed, it is dried until the moisture content is 30wt% to obtain fermented organic matter.

[0048] The method for preparing the coated suspension of the present invention specifically includes the following steps: 1) Under a nitrogen atmosphere, corn stalk powder was heated to 500℃ and calcined for 4 h, then cooled to room temperature to obtain biochar; the biochar was added to a nitric acid solution with a nitric acid content of 3 mol / L and oxidized for 5 h, centrifuged, washed, and dried to obtain oxidized biochar; the feeding ratio of biochar to nitric acid solution was 15 g: 100 mL.

[0049] 2) The oxidized biochar prepared in step 1) is ultrasonically dispersed in deionized water at a ratio of 1 g to 400 mL to obtain an oxidized biochar suspension. A 16 wt% alkaline solution is added dropwise to adjust the pH to 9. Limonene epoxide is then added and the mixture is stirred at 80 °C for 8 h. The mass of limonene epoxide is 15 wt% of the mass of the oxidized biochar in the oxidized biochar suspension. After washing and drying, limonene epoxide-modified biochar is obtained.

[0050] 3) The limonene epoxide-modified biochar was ultrasonically dispersed in deionized water for 60 min to obtain a coated suspension; the concentration of the coated suspension was 6% wt.

[0051] A method for preparing an environmentally friendly bio-organic fertilizer specifically includes the following steps: (1) Bacillus subtilis was inoculated into LB medium at an inoculation rate of 4 v / v % and cultured at 37°C for 24 h to obtain Bacillus subtilis bacterial suspension; the effective viable count of the Bacillus subtilis bacterial suspension was ≥1.0×10⁻⁶. 8 CFU / mL.

[0052] (2) The Bacillus subtilis culture obtained in step (1) is inoculated into the fermentation medium at an inoculation amount of 5 v / v % and fermented at 37℃ for 72 h to obtain the fermentation broth. After spray drying, the microbial agent is obtained. The fermentation medium contains 18 g / L sucrose, 4 g / L D-glucosamine sulfate potassium salt, 12 g / L peptone, 7 g / L yeast extract, 5 g / L carotene, 1 g / L MgSO4·7H2O, 5 g / L MnSO4·H2O, and 30 mg / L CaCl2.

[0053] (3) Weigh out the microbial agent and fermented organic matter according to the weight proportions, crush it, pass it through a 100-mesh sieve, and make it into granules; spray the coated suspension evenly on the surface of the granules, dry it, and you will get an environmentally friendly bio-organic fertilizer.

[0054] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that D-glucosamine potassium sulfate in step (2) of the preparation method of an environmentally friendly bio-organic fertilizer is omitted, while all other aspects are the same as in Example 1.

[0055] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that in step 3) of the preparation method of the coated suspension, the limonene epoxide modified biochar is replaced with the biochar in step 1), while all other aspects are the same as in Example 1.

[0056] Experimental Example 1 To evaluate the effect of different fermentation media on the number of viable microorganisms, the specific experimental steps are as follows: 1 mL of the fermentation broth prepared in step (2) of Examples 1-3 and Comparative Example 1 was weighed and placed in 9 mL of sterile physiological saline for a 10-fold dilution, followed by sequential dilution to the desired gradient. The total number of viable microorganisms in the fermentation broth of different groups was determined by the plate count method, and the results are shown in Table 1.

[0057] Table 1 Determination of total viable bacterial count As shown in Table 1, compared with Comparative Example 1, the fermentation broth prepared in Examples 1-3 of this invention has a higher total number of viable bacteria. This indicates that D-glucosamine potassium sulfate has the dual functions of a highly efficient microbial growth promoter and a high-quality carbon and nitrogen source, which can significantly promote the activity and proliferation of Bacillus subtilis, thereby increasing the total number of viable bacteria in the microbial agent. This lays a solid foundation for the preparation of highly active microbial agents and ultimately ensures the stable performance of the comprehensive functions of the fertilizer product.

[0058] Experimental Example 2 To evaluate the slow-release properties of the environmentally friendly bio-organic fertilizers prepared in Examples 1-3 and Comparative Example 2, the nitrogen (N) release rate was determined. The specific experimental steps are as follows: 1.0 g of each of the environmentally friendly bio-organic fertilizers prepared in Examples 1-3 and Comparative Example 2 were weighed and placed in Erlenmeyer flasks, with 400 mL of deionized water added. The flasks were placed in a 25℃ constant temperature water bath shaker for 50 h. Samples were taken at 0 h, 4 h, 8 h, 15 h, 25 h, and 50 h. After each sampling, the sample was centrifuged at 6000 r / min for 5 min, and the supernatant was filtered through a 0.45 μm aqueous filter membrane. The total nitrogen concentration in the filtrate was determined using the standard method of "Methods for Monitoring and Analysis of Water and Wastewater". Each treatment was repeated three times. The effects of different environmentally friendly bio-organic fertilizers on the nitrogen release rate are shown below. Figure 2 As shown.

[0059] The results are as follows Figure 2 The figure shown illustrates the impact of different environmentally friendly bio-organic fertilizers on nitrogen release rates. Figure 2 It can be seen that, compared with Comparative Example 2, the environmentally friendly bio-organic fertilizers prepared in Examples 1-3 of this invention can significantly reduce the release rate of nitrogen, exhibiting a good slow-release effect. This indicates that by grafting limonene epoxide with biochar, a terpene hydrophobic framework is introduced onto its surface, forming a directionally arranged hydrophobic barrier. This barrier effectively delays the premature dissolution and loss of nutrients through both physical barrier and ion exchange, achieving controlled nutrient release and thus significantly improving fertilizer utilization.

[0060] Experimental Example 3 This experiment aims to systematically evaluate the effects of the environmentally friendly bio-organic fertilizers prepared in Examples 1-3 and Comparative Examples 1-2 of this invention on tomato growth, yield, and fruit quality. The specific experimental steps are as follows: (1) The experiment consisted of six treatment groups: Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and blank control group. All groups were planted using a raised bed method with a bed height of 0.3m and a plant spacing of 0.3m; each group was separated by a field ridge (50cm wide and 20cm high). The environmentally friendly bio-organic fertilizers prepared in Examples 1-3 and Comparative Examples 1-2 were applied together with conventional fertilizers, with the application rate of the environmentally friendly bio-organic fertilizer being 500kg / hm. 2 The application rate of conventional fertilizer is 1500 kg / hm. 2 The conventional fertilizer was an organic-inorganic compound fertilizer (with organic matter ≥20%, total nitrogen content 15%, P2O5 content 5%, and K2O content 10%). The control group did not receive environmentally friendly bio-organic fertilizer, only conventional fertilizer.

[0061] (2) After the fruits matured, they were harvested in groups, weighed, and the yield of each group was recorded. During the peak fruiting period of tomatoes, about 1000g of tomato bunches with basically uniform maturity and free from pests and diseases were taken from each group for quality index determination. The methods for determining the quality index of tomato fruits are as follows: vitamin C content was determined by 2,6-dichlorophenolindophenol titration, soluble sugar content was determined by sulfuric acid anthrone colorimetric method, titratable acid content was determined by NaOH titration, nitrate content was determined by ultraviolet spectrophotometry, and the sugar-acid ratio was calculated by the ratio of soluble sugar content to titratable acid content. The results are shown in Table 2.

[0062] Table 2. Effects of different environmentally friendly bio-organic fertilizers on tomato yield and quality. The results are shown in Table 2, illustrating the effects of different environmentally friendly bio-organic fertilizers on tomato yield and quality. Table 2 shows that, compared to the blank control group, Comparative Example 1, and Comparative Example 2, the environmentally friendly bio-organic fertilizers prepared in Examples 1-3 of this invention significantly promoted tomato yield, vitamin C content, and sugar-acid ratio, and significantly reduced nitrate content. Example 1 showed the most significant effect. This indicates that the environmentally friendly bio-organic fertilizer prepared by this invention can effectively promote tomato growth, significantly improving fruit nutritional quality and edibility while increasing tomato yield.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. Based on the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of protection claimed by the present invention.

Claims

1. An environmentally friendly bio-organic fertilizer, characterized in that, The raw materials include the following parts by weight: 70-90 parts fermented organic matter, 8-13 parts microbial inoculants, and 10-15 parts coated suspension.

2. The method for preparing an environmentally friendly bio-organic fertilizer according to claim 1, characterized in that, Specifically, the following steps are included: (1) Activate Bacillus subtilis to obtain Bacillus subtilis bacterial solution; (2) The Bacillus subtilis bacterial solution obtained in step (1) is inoculated into a fermentation medium and fermented to obtain a fermentation broth. After spray drying, the microbial agent is obtained. (3) Mix the microbial agent obtained in step (2) with the fermented organic matter, crush it, pass it through an 80-100 mesh sieve, and make it into granules; spray the coated suspension evenly on the surface of the granules, dry it, and you will get an environmentally friendly bio-organic fertilizer.

3. The method for preparing an environmentally friendly bio-organic fertilizer according to claim 2, characterized in that, The preparation method of the coated suspension specifically includes the following steps: 1) Under a nitrogen atmosphere, corn stalk powder is heated to 350-500℃ and calcined for 2-4 hours, then cooled to room temperature to obtain biochar; the biochar is added to nitric acid solution for oxidation for 3-5 hours, centrifuged, washed, and dried to obtain oxidized biochar. 2) The oxidized biochar prepared in step 1) is ultrasonically dispersed in deionized water to obtain an oxidized biochar suspension. Alkali solution is added dropwise to adjust its pH value to 8-9, limonene epoxide is added, and the mixture is stirred for 6-8 h. After washing and drying, limonene epoxide modified biochar is obtained. 3) The limonene epoxide-modified biochar was ultrasonically dispersed in deionized water to obtain a coated suspension.

4. The method for preparing an environmentally friendly bio-organic fertilizer according to claim 3, characterized in that, In step 1), the nitric acid content in the nitric acid solution is 1-3 mol / L; the feed ratio of biochar to nitric acid solution is (10-15) g: 100 mL.

5. The method for preparing an environmentally friendly bio-organic fertilizer according to claim 3, characterized in that, In step 2), the ratio of oxidized biochar to deionized water is 1 g: 200-400 mL; the concentration of the alkali solution is 12-16 wt%; the mass of the limonene epoxide is 10-15 wt% of the mass of the oxidized biochar; and the mixing temperature is 70-80℃.

6. The method for preparing an environmentally friendly bio-organic fertilizer according to claim 3, characterized in that, The ultrasonic dispersion time in step 3) is 30-60 min; the concentration of the coated suspension is 4-6 wt%.

7. The method for preparing an environmentally friendly bio-organic fertilizer according to claim 2, characterized in that, The specific steps for activating Bacillus subtilis in step (1) are as follows: Bacillus subtilis is inoculated into LB medium at an inoculation rate of 2-4 v / v %, and cultured at 30-37℃ for 16-24 h to obtain Bacillus subtilis bacterial suspension; the effective viable count of the Bacillus subtilis bacterial suspension is ≥1.0×10⁻⁶. 8 CFU / mL.

8. The method for preparing an environmentally friendly bio-organic fertilizer according to claim 2, characterized in that, In step (2), the inoculum size is 3-5 v / v %; the fermentation temperature is 30-37℃; the fermentation time is 48-72h; the concentration of sucrose in the fermentation medium is 15-18g / L, the concentration of D-glucosamine potassium sulfate is 2-4g / L, the concentration of peptone is 10-12g / L, the concentration of yeast extract is 5-7g / L, the concentration of carotene is 3-5g / L, the concentration of MgSO4·7H2O is 0.4-1g / L, the concentration of MnSO4·H2O is 3-5g / L, and the concentration of CaCl2 is 25-30mg / L.

9. The method for preparing an environmentally friendly bio-organic fertilizer according to claim 2, characterized in that, The method for preparing the fermented organic matter specifically includes the following steps: S1. Poultry and livestock manure and corn stalks are dried separately by ventilation, crushed, and passed through an 80-100 mesh sieve to obtain the material; S2. Put the material obtained in step S1 into the fermentation tank and mix it evenly. Add water to make the water content of the system 50-60wt%. Then add EM bacterial solution and seal the fermentation tank with plastic film. Turn the fermentation pile once every 2-3 days until the material is completely decomposed. S3 After the material has decomposed, it is dried until the moisture content is 20-30 wt%, which yields fermented organic matter.

10. The method for preparing an environmentally friendly bio-organic fertilizer according to claim 9, characterized in that, The weight ratio of poultry and livestock manure to corn stalks is 1:(1-1.5); the amount of EM bacterial solution added is 0.3-0.5 wt% of the total weight of poultry and livestock manure and corn stalks.

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