Compound microbial organic fertilizer and preparation method thereof

Abstract

The invention discloses a compound microbial organic fertilizer and a preparation method thereof, and belongs to the technical field of compound microbial organic fertilizers. The compound microbial organic fertilizer is prepared from the following raw materials in parts by weight: 8-12 parts of a microbial agent, 30-35 parts of livestock and poultry manure, 20-25 parts of crop straws, 10-15 parts of humic acid, 10-12 parts of bagasse carbon, 3-5 parts of rumen bypass fat powder, 3-5 parts of molasses and 1-3 parts of chitosan oligosaccharide. According to the compound microbial organic fertilizer, the nitrogen-fixing pseudomonas, the streptomyces elongisporus and the paenibacillus polymyxa are selected to be compounded, and the three strains comprehensively promote root development, nutrient absorption and stress resistance of strawberry plants through the synergistic effect of nitrogen fixation, nutrient activation, hormone secretion and disease inhibition. The compound microbial organic fertilizer can effectively promote growth of strawberry plants, improve the quality of strawberries, increase the yield, reduce chemical fertilizer and pesticide residues, reduce the risk of soil pollution and meet the requirements of consumers for safe and organic strawberries.

Description

Technical Field

[0001] The present invention belongs to the technical field of compound microbial organic fertilizers, and particularly relates to a compound microbial organic fertilizer and a preparation method thereof. Background Art

[0002] Strawberries are perennial herbaceous plants of the genus Fragaria in the Rosaceae family. Their fruits contain rich nutrients such as vitamin C, malic acid, glucose, and citric acid, and are known as the "queen of fruits". Moreover, the strawberry industry has become a characteristic industry for farmers to increase their income due to advantages such as a short production cycle and high economic benefits. With the improvement of people's living quality, people are increasingly pursuing healthy foods, and thus the demand for high-quality strawberries is increasing day by day.

[0003] Organic fertilizers contain a large amount of active substances required during the growth process of plants. Applying organic fertilizers is beneficial to the vigorous growth and improvement of stress resistance of plants, and can also adjust the soil pH value, etc. Organic fertilizers are rich in organic matter, and the organic acid substances produced by their decomposition can promote the further activation of mineral elements in the soil, thereby improving the fertilizer utilization rate. Applying organic fertilizers can also greatly improve the quality indicators of fruits. Relevant research shows that as the amount of organic fertilizer applied increases, the soluble solids, vitamin C content, and sugar content in strawberry fruits also increase, while the titratable acid content decreases significantly. It can be seen that applying organic fertilizers is beneficial to improving the quality of strawberries. And microbial organic fertilizers are a type of fertilizer composed of specific functional microorganisms and organic materials. Its core feature is that through the activities of microorganisms, organic matter is decomposed and converted into nutrients that can be absorbed by plants, while improving the soil microecology and promoting crop growth.

[0004] For example, Chinese Patent Application CN201610546465.6 discloses a special microbial organic fertilizer for strawberries and a preparation method thereof. The organic fertilizer prepared by this invention is specifically used for strawberry cultivation. The fermented organic fertilizer not only has no odor but also has a loose texture, is convenient for fertilization, has good water absorption and air permeability, and has a high organic matter content, and can effectively solve the problem of strawberry continuous cropping obstacles. However, this microbial organic fertilizer does not improve the quality of strawberries. Therefore, it is of great significance for strawberry cultivation to prepare a biological organic fertilizer that can continuously provide sufficient nutrition for strawberry plants, promote the growth of strawberry plants, and improve the quality of strawberry fruits. Summary of the Invention

[0005] The purpose of the present invention is to provide a compound microbial organic fertilizer to comprehensively promote the root development, nutrient absorption, stress resistance of strawberry plants, and improve the fruit quality, while reducing the residues of chemical fertilizers and pesticides, reducing the risk of soil pollution, and meeting the needs of consumers for safe and organic strawberries.

[0006] To achieve the above technical purpose, the technical solution adopted by the present invention is as follows:

[0007] A compound microbial organic fertilizer comprises the following raw materials in parts by weight: 8-12 parts of microbial inoculum, 30-35 parts of livestock and poultry manure, 20-25 parts of crop straws, 10-15 parts of humic acid, 10-12 parts of bagasse charcoal, 3-5 parts of bypass fat powder, 3-5 parts of molasses, and 1-3 parts of chitosan oligosaccharide.

[0008] Further, the microbial inoculum includes Pseudomonas azotofixans, Streptomyces longisporus, and Paenibacillus polymyxa; the Pseudomonas azotofixans is purchased from the China Center for Type Culture Collection, with the preservation number CCTCC S2013531 and the original preservation date of March 28, 2014; the Streptomyces longisporus is purchased from the China Center for Type Culture Collection, with the preservation number CCTCC AA94048 and the original preservation date of March 26, 2009; the Paenibacillus polymyxa is purchased from the China Center for Type Culture Collection, with the preservation number CCTCC AB 2013073; the original preservation date is March 18, 2013.

[0009] Further, the preparation method of the microbial inoculum is as follows:

[0010] Pseudomonas azotofixans, Streptomyces longisporus, and Paenibacillus polymyxa are respectively cultured in a seed medium for 48 h, then inoculated into an LB medium at an inoculation amount of 5%, and cultured until the bacterial concentration OD 600 = 3.0 to obtain a medium bacterial liquid, and then the three bacterial liquids are mixed evenly according to a volume ratio of 1:1:1, freeze-dried into a freeze-dried powder to obtain the microbial inoculum.

[0011] Further, the preparation method of the bagasse charcoal is as follows:

[0012] The bagasse is rinsed with water to remove impurities, naturally dried until the moisture content is lower than 15%, the dried bagasse is broken into small pieces of 3-5 cm, the bagasse is put into a carbonization furnace, and the temperature is raised to 400 °C at a rate of 10 °C / min under anaerobic conditions, carbonized for 2 h, the heating is turned off, and the inert gas is continuously introduced for cooling to obtain the bagasse charcoal.

[0013] A preparation method of a compound microbial organic fertilizer includes the following steps:

[0014] (1) Fermentation and composting: The livestock and poultry manure and crop straws are respectively dried by ventilation, crushed through a 100-mesh sieve, put into a fermentation tank and mixed evenly, the water content is controlled at 50-60% by adding water, and then EM bacterial liquid is added. The fermentation tank is sealed with a plastic film, and the fermentation process is turned over once every 3 days until the composting is completed, and then spread out and dried until the water content ≤ 40% to obtain the fermented organic matter;

[0015] (2) Preparation of the microbial inoculum and bagasse charcoal;

[0016] (3) Granulation: Mix the microbial inoculant prepared in step (2) and bagasse carbon evenly, then add molasses and mix well. After mixing evenly, add the fermented organic matter, humic acid, and chitosan oligosaccharide prepared in step (1), stir and mix evenly, dry to a water content of ≤ 15%, granulate with a granulator, screen out particles with a particle size of 3 - 5 mm, put the particles into a spiral mixer, stir at a speed of 20 - 30 r / min, and evenly spray the bypass fat powder onto the surface of the particles through a sprayer during the stirring process. Keep stirring for 10 min to make the fat powder evenly distributed on the surface of the particles, and spread out the particles to cool naturally to obtain the final product, the compound microbial organic fertilizer particles.

[0017] Further, the livestock and poultry manure is pig manure; the crop straw is peanut straw; the addition amount of the EM bacterial liquid is 0.1% of the total weight of the manure and straw.

[0018] Further, the application of the compound microbial organic fertilizer of the present invention in strawberry planting.

[0019] All raw materials used in the present invention are commercially available.

[0020] The nitrogen-fixing Pseudomonas of the present invention converts atmospheric nitrogen into ammonium nitrogen through biological nitrogen fixation, directly supplementing the nitrogen demand of strawberries. During the vegetative growth period of strawberries, the nitrogen demand is relatively high. This bacterium can reduce the nitrogen fertilizer input by 30 - 50%, and at the same time avoid soil acidification caused by chemical nitrogen fertilizers. In addition, it can secrete the plant hormone indoleacetic acid, promoting root development and increasing the root surface area and absorption capacity. Paenibacillus polymyxa has the functions of phosphorus and potassium solubilization, can secrete organic acids and phosphatases, release the fixed phosphorus in the soil, and its produced siderophores can chelate insoluble potassium, convert the insoluble phosphorus and potassium in the soil into an absorbable form, improve the utilization rate of mineral nutrients by strawberries, and at the same time can produce indoleacetic acid. Streptomyces longisporus inhibits Botrytis cinerea bacteria by secreting antibiotic substances such as actinomycin, reduces the occurrence of strawberry diseases, and at the same time regulates the soil microecology and reduces the risk of soil-borne diseases. The combined action of the three bacteria can improve the resistance of strawberries to root rot and promote the growth of strawberries.

[0021] Humic acid is added during the preparation process of the organic fertilizer of the present invention. Humic acid and microbial metabolites can enhance the cell wall structure, improve the fruit hardness, and avoid external surface damage during strawberry transportation. The present invention realizes the resource utilization of agricultural waste by the composting fermentation of peanut straw and pig manure, reduces environmental pollution, and at the same time reduces the cost of chemical fertilizer use. At the same time, the composted corn straw will release a large amount of nitrogen, phosphorus, and potassium, especially potassium element, which is crucial for strawberry fruit swelling and sugar accumulation.

[0022] In the preparation process of the organic fertilizer of the present invention, protected fat powder and molasses are added. The protected fat powder has the property of anti-decomposition, reduces the excessive consumption of microorganisms during the fertilizer processing, provides a long-acting carbon source, continuously supports the microbial activities, avoids the rapid release of nutrients, extends the fertilizer efficiency. In addition, the protected fat powder forms a hydrophobic protective film on the particle surface, reduces the moisture absorption and caking phenomena of the organic fertilizer particles during storage and transportation, reduces the loss of volatile nutrients such as nitrogen and potassium, and improves the nutrient utilization rate. The protected fat powder decomposes slowly in the soil, and releases fatty acids after decomposition, improving the soil aggregate structure and enhancing the air permeability and water retention. Molasses is rich in carbon sources such as sucrose and glucose, activates the microbial inoculant, and ensures its normal survival and proliferation. To enhance the stability of microorganisms, sugarcane bagasse charcoal is prepared, and the pores inside the biochar are used to adsorb and protect microorganisms.

[0023] Beneficial effects

[0024] For the compound microbial organic fertilizer of the present invention, three strains of Pseudomonas azotofixans, Streptomyces longisporus, and Paenibacillus polymyxa are selected for compounding. Through the synergistic effects of nitrogen fixation, nutrient activation, hormone secretion, disease inhibition, and microbiome regulation, the three strains comprehensively promote the root development, nutrient absorption, stress resistance of strawberry plants, and improve the fruit quality.

[0025] The compound microbial organic fertilizer of the present invention significantly improves the soil fertility in the rhizosphere of strawberries, improves the quality and yield of strawberries, reduces the residues of chemical fertilizers and pesticides at the same time, reduces the risk of soil pollution, and meets the needs of consumers for safe and organic strawberries. Specific embodiments

[0026] The technical solutions of the present invention will be further described below in conjunction with specific embodiments, but are not limited thereto.

[0027] Example 1

[0028] A compound microbial organic fertilizer, comprising the following raw materials in parts by weight: 8 parts of microbial inoculant, 30 parts of livestock and poultry manure, 20 parts of crop straw, 10 parts of humic acid, 10 parts of sugarcane bagasse charcoal, 3 parts of protected fat powder, 3 parts of molasses, and 1 part of chitosan oligosaccharide.

[0029] The microbial inoculant includes Pseudomonas azotofixans, Streptomyces longisporus, and Paenibacillus polymyxa; the Pseudomonas azotofixans is purchased from the China Center for Type Culture Collection, with the preservation number of CCTCC S2013531 and the original preservation date of March 28, 2014; the Streptomyces longisporus is purchased from the China Center for Type Culture Collection, with the preservation number of CCTCC AA 94048 and the original preservation date of March 26, 2009; the Paenibacillus polymyxa is purchased from the China Center for Type Culture Collection, with the preservation number of CCTCC AB 2013073; the original preservation date is March 18, 2013.

[0030] The preparation method of the microbial inoculum is as follows:

[0031] Pseudomonas azotofixans, Streptomyces longisporus, and Paenibacillus polymyxa are respectively cultured in a seed medium for 48 h, and then inoculated into an LB medium at an inoculation amount of 5%, and cultured until the bacterial concentration OD 600 = 3.0 to obtain a medium bacterial liquid, and then the three bacterial liquids are mixed evenly according to a volume ratio of 1:1:1, freeze-dried into a freeze-dried powder to obtain the microbial inoculum.

[0032] The preparation method of the bagasse charcoal is as follows:

[0033] The bagasse is rinsed with water to remove impurities, naturally dried until the moisture content is lower than 15%, the dried bagasse is broken into small pieces of 3 - 5 cm, the bagasse is put into a carbonization furnace, and the temperature is raised to 400 °C at a rate of 10 °C / min under anaerobic conditions, carbonized for 2 h, the heating is turned off, and an inert gas is continuously introduced for cooling to obtain bagasse charcoal.

[0034] A preparation method of a compound microbial organic fertilizer includes the following steps:

[0035] (1) Fermentation and composting: The livestock and poultry manure and crop straw are respectively dried by ventilation, crushed through a 100-mesh sieve, put into a fermentation tank and mixed evenly, water is added to control the water content at 50 - 60%, and then EM bacterial liquid is added. The fermentation tank is sealed with a plastic film, and the fermentation process is turned over once every 3 days until composting is completed, and then spread out and dried until the water content ≤ 40% to obtain fermented organic matter;

[0036] (2) Preparation of the microbial inoculum and bagasse charcoal;

[0037] (3) Granulation: The microbial inoculum and bagasse charcoal prepared in step (2) are mixed evenly, then molasses is added and mixed evenly. After mixing evenly, the fermented organic matter, humic acid, and chitosan oligosaccharide prepared in step (1) are added, stirred and mixed evenly, dried until the water content ≤ 15%, granulated by a granulator, and particles with a particle size of 3 - 5 mm are screened out. The particles are put into a spiral mixer and stirred at a speed of 20 - 30 r / min. During the stirring process, the bypass-protected fat powder is evenly sprayed onto the surface of the particles through a sprayer, and stirring is continued for 10 min to make the fat powder evenly distributed on the surface of the particles, and the particles are spread out and naturally cooled to obtain the final product of the compound microbial organic fertilizer particles.

[0038] The livestock and poultry manure is pig manure; the crop straw is peanut straw; the addition amount of the EM bacterial liquid is 0.1% of the total weight of the manure and straw.

[0039] Example 2

[0040] A compound microbial organic fertilizer, comprising the following raw materials in parts by weight: 10 parts of microbial inoculum, 32 parts of livestock and poultry manure, 23 parts of crop straw, 13 parts of humic acid, 11 parts of bagasse charcoal, 4 parts of bypass fat powder, 4 parts of molasses, and 2 parts of chitosan oligosaccharide.

[0041] The microbial inoculum includes Pseudomonas azotofixans, Streptomyces longisporus, and Paenibacillus polymyxa; the Pseudomonas azotofixans is purchased from the China Center for Type Culture Collection, with the preservation number CCTCC S2013531 and the original preservation date of March 28, 2014; the Streptomyces longisporus is purchased from the China Center for Type Culture Collection, with the preservation number CCTCC AA 94048 and the original preservation date of March 26, 2009; the Paenibacillus polymyxa is purchased from the China Center for Type Culture Collection, with the preservation number CCTCC AB 2013073; the original preservation date is March 18, 2013.

[0042] The preparation method of the microbial inoculum is as follows:

[0043] Pseudomonas azotofixans, Streptomyces longisporus, and Paenibacillus polymyxa are respectively cultured in a seed medium for 48 h, then inoculated into an LB medium at an inoculation amount of 5%, and cultured until the bacterial concentration OD 600 = 3.0 to obtain a medium bacterial liquid, and then the three bacterial liquids are mixed evenly according to a volume ratio of 1:1:1 and freeze-dried into a freeze-dried powder to obtain the microbial inoculum.

[0044] The preparation method of the bagasse charcoal is as follows:

[0045] The bagasse is rinsed with water to remove impurities, naturally dried until the moisture content is lower than 15%, the dried bagasse is broken into small pieces of 3 - 5 cm, the bagasse is put into a carbonization furnace, and the temperature is raised to 400 °C at a rate of 10 °C / min under anaerobic conditions, carbonized for 2 h, the heating is turned off, and the inert gas is continuously introduced for cooling to obtain the bagasse charcoal.

[0046] A preparation method of a compound microbial organic fertilizer, comprising the following steps:

[0047] (1) Fermentation and composting: After the livestock and poultry manure and crop straw are respectively dried by ventilation, crushed and passed through a 100-mesh sieve, put into a fermentation tank and mixed evenly, add water to control the moisture content at 50 - 60%, then add EM bacterial liquid, seal the fermentation tank with a plastic film, turn the pile once every 3 days during the fermentation process until the composting is completed, and then spread it out to dry until the moisture content ≤ 40% to obtain the fermented organic matter;

[0048] (2) Preparation of microbial inoculum and bagasse charcoal;

[0049] (3) Granulation: Mix the microbial inoculant prepared in step (2) and bagasse carbon evenly, then add molasses and mix well. After mixing evenly, add the fermented organic matter, humic acid, and chitosan oligosaccharide prepared in step (1), stir and mix evenly, dry to a water content of ≤ 15%, granulate with a granulator, screen out particles with a particle size of 3 - 5 mm, put the particles into a spiral mixer, stir at a speed of 20 - 30 r / min, and evenly spray the bypass fat powder onto the surface of the particles through a sprayer during the stirring process. Keep stirring for 10 min to make the fat powder evenly distributed on the surface of the particles, and spread out the particles to cool naturally to obtain the final product, the compound microbial organic fertilizer particles.

[0050] The livestock and poultry manure is pig manure; the crop straw is peanut straw; the addition amount of the EM bacterial liquid is 0.1% of the total weight of the manure and straw.

[0051] Example 3

[0052] A compound microbial organic fertilizer, comprising the following raw materials in parts by weight: 12 parts of microbial inoculant, 35 parts of livestock and poultry manure, 25 parts of crop straw, 15 parts of humic acid, 12 parts of bagasse carbon, 5 parts of bypass fat powder, 5 parts of molasses, and 3 parts of chitosan oligosaccharide.

[0053] The microbial inoculant includes Pseudomonas azotofixans, Streptomyces longisporus, and Paenibacillus polymyxa; the Pseudomonas azotofixans is purchased from the China Center for Type Culture Collection, with the preservation number CCTCC S2013531 and the original preservation date of March 28, 2014; the Streptomyces longisporus is purchased from the China Center for Type Culture Collection, with the preservation number CCTCC AA 94048 and the original preservation date of March 26, 2009; the Paenibacillus polymyxa is purchased from the China Center for Type Culture Collection, with the preservation number CCTCC AB 2013073; the original preservation date is March 18, 2013.

[0054] The preparation method of the microbial inoculant is as follows:

[0055] Culture Pseudomonas azotofixans, Streptomyces longisporus, and Paenibacillus polymyxa in a seed medium for 48 h respectively, then inoculate them into an LB medium at an inoculation amount of 5%, and culture until the bacterial concentration OD 600 = 3.0 to obtain the middle bacterial liquid, and then mix the three bacterial liquids evenly according to the volume ratio of 1:1:1, and freeze-dry them into freeze-dried powder to obtain the microbial inoculant.

[0056] The preparation method of the bagasse carbon is as follows:

[0057] Wash the bagasse with water to remove impurities, and naturally dry it until the moisture content is lower than 15%. Crush the dried bagasse into small pieces of 3 - 5 cm, put the bagasse into a carbonization furnace, and raise the temperature to 400 °C at a rate of 10 °C / min under anaerobic conditions, carbonize for 2 h, turn off the heating, and continue to introduce inert gas for cooling to obtain bagasse charcoal.

[0058] A preparation method of a composite microbial organic fertilizer includes the following steps:

[0059] (1) Fermentation and composting: After ventilating and drying poultry manure and crop straw respectively, crush them through a 100 - mesh sieve, put them into a fermentation tank and mix evenly, add water to control the water content at 50 - 60%, then add EM bacterial liquid, seal the fermentation tank with a plastic film, turn the pile once every 3 days during the fermentation process until composting is completed, then spread it out to dry until the water content ≤ 40% to obtain fermented organic matter;

[0060] (2) Prepare microbial inoculant and bagasse charcoal;

[0061] (3) Pelletizing: Mix the microbial inoculant and bagasse charcoal prepared in step (2) evenly, then add molasses and mix well. After mixing evenly, add the fermented organic matter, humic acid, and chitosan oligosaccharide prepared in step (1), stir and mix evenly, dry until the water content ≤ 15%, granulate with a granulator, screen out particles with a particle size of 3 - 5 mm, put the particles into a spiral mixer, stir at a speed of 20 - 30 r / min, and evenly spray the bypass fat powder onto the surface of the particles through a sprayer during the stirring process, continuously stir for 10 min to make the fat powder evenly distributed on the surface of the particles, and spread out the particles to cool naturally to obtain the final product of composite microbial organic fertilizer particles.

[0062] The poultry manure is pig manure; the crop straw is peanut straw; the addition amount of the EM bacterial liquid is 0.1% of the total weight of the manure and straw.

[0063] Control group

[0064] In each control group, change the volume ratio of Pseudomonas azotobacter, Streptomyces longisporus, and Paenibacillus polymyxa in the microbial inoculant, and the remaining raw materials and steps are the same as in Example 3.

[0065] Table 1 Composition of the bacterial liquid in each control group

[0066] Group Component Pseudomonas azotofixans (a) Streptomyces longisporus (b) Paenibacillus polymyxa (c) Control Example 1 a + b + c 1 2 1 Control Example 2 a + b + c 1 1 2 Control Example 3 a + b + c 2 1 1 Control Example 4 a + b 1 1 0 Control Example 5 a + c 1 0 1 Control Example 6 b + c 0 1 1 Control Example 7 a 1 0 0 Control Example 8 b 0 1 0 Control Example 9 c 0 0 1

[0067] Performance test

[0068] Identification of the growth - promoting ability of strains

[0069] The molybdenum-antimony anti-colorimetric method was used to determine the phosphorus-solubilizing ability of the strains; the flame atomic spectrophotometer method was used to determine the potassium-solubilizing ability of the strains; the carbon-nitrogen analyzer was used to determine the nitrogen-fixing ability of the strains; the Salkowski colorimetric solution colorimetric method was used to determine the indole acetic acid secretion ability of the strains; the CAS liquid phase colorimetric method was used to determine the siderophore synthesis ability of the strains.

[0070] Table 2 Identification of the growth-promoting ability of strains

[0071]

[0072] Verification of the antibacterial effect of the microbial bacterial liquid:

[0073] Pathogen inhibition test: Using the plate confrontation method, the pathogens of strawberry gray mold and root rot were placed on a PDA plate for activation culture. A 5-mm bacterial cake was punched out. The bacterial cakes of each pathogen were placed in the center of a new PDA plate. Two sterile filter papers were placed about 2.5 cm away from the center of the plate. 10 μL of the mixed microbial bacterial liquid of Example 3 was dropped on each filter paper, and the addition of LB liquid medium was used as a blank control. Each treatment was repeated 6 times and cultured at a constant temperature of 25°C. After three days of culture, the diameter of the fungal colony of the pathogen was measured, and the average value was taken to calculate the inhibition rate. The data are shown in Table 3.

[0074] Table 3 Antibacterial effect of the microbial bacterial liquid

[0075] Pathogenic bacteria Control Group (mm) Colony Diameter of Treatment Group (mm) Inhibitory Rate (%) Botrytis cinerea 68 32 57.1 Rhizoctonia solani 59 24 64.8

[0076] It can be seen from Table 3 that the mixed bacterial liquid of the three microorganisms selected in the present invention has a good antagonistic effect against the pathogens of strawberry gray mold and root rot.

[0077] Planting experiment

[0078] The planting experiment was carried out in the plastic greenhouse of the company's experimental base. The strawberry variety for testing was Zhangji. 13 treatment groups were set up, and the microbial organic fertilizers of Examples 1-3 and Comparative Examples 1-9 were applied respectively. Another group did not apply any fertilizer. Each treatment group was 100 m 2 , randomly arranged in blocks, and the fertilization amount of each treatment group was 600 kg / mu. The fertilizer was evenly spread before ridging. High-ridge cultivation was adopted, with a ridge width of 60 cm, a ridge height of 30 cm, and a ditch width of 30 cm. Two rows were planted on each ridge, and the plant spacing was 18 cm. Bees were used for pollination during the flowering period, and other management measures were the same as those in conventional field management.

[0079] Four months after strawberry planting, 10 strawberry plants were selected from each treatment group to measure the plant height and plant width of the strawberry plants in each treatment group; during the fruit harvest period, the five-point sampling method was used to select 10 mature fruits of strawberries to measure the longitudinal diameter, transverse diameter, single fruit weight, and single plant yield of the fruit. The above data are shown in Table 4. The soluble solid content of the harvested fruit was measured by the refractometer method, and the fruit hardness was measured by the fruit hardness meter. The data results are shown in Table 5.

[0080] Table 4 Plant and fruit characteristics of strawberries under different treatments

[0081] Group Plant Height / cm Plant Width / cm Fruit Longitudinal Diameter / cm Fruit Transverse Diameter / cm Average Single Fruit Weight / g Average Single Plant Yield / g Example 1 22.8 35.6 4.98 3.04 17.2 214.4 Example 2 23.1 35.8 5.04 3.07 17.3 218.5 Example 3 23.3 36.1 5.06 3.11 17.6 223.7 Control Example 1 22.0 34.2 4.84 2.93 16.8 205.3 Control Example 2 22.4 34.7 4.92 3.02 17.1 212.5 Control Example 3 22.5 34.6 4.87 2.98 16.9 208.9 Control Example 4 20.8 33.1 4.65 2.82 15.7 185.6 Control Example 5 21.7 33.9 4.83 2.88 16.3 201.4 Control Example 6 21.3 33.5 4.76 2.85 16.0 196.2 Control Example 7 19.8 32.6 4.59 2.79 15.2 173.9 Control Example 8 19.1 32.1 4.47 2.75 14.9 167.1 Control Example 9 20.5 32.8 4.61 2.86 15.5 181.8 Control Group 17.6 31.4 4.35 2.72 14.6 161.5

[0082] As shown in Table 4, compared with the blank control, after applying the composite microbial organic fertilizer prepared by Examples 1-3 of the present invention, the strawberry plants grew more luxuriantly, the fruits were larger and fuller, and the strawberry yield per plant was significantly improved. The data of the comparative examples 1-9 with changed inoculant composition in terms of strawberry plant traits and fruit traits all decreased to varying degrees, indicating that the three selected bacteria in the composite microbial inoculant of the present invention are weak in effect if one is missing, and each bacteria is indispensable for the preparation of the composite microbial organic fertilizer of the present invention.

[0083] Table 5 Fruit quality traits under different treatments

[0084]

[0085]

[0086] As shown in Table 5, the application of the composite microbial organic fertilizer of Examples 1-3 of the present invention can significantly increase the soluble solid content of strawberry fruit, and the soluble solid content of the fruit tip and the flesh is slightly different, the flesh is sweeter and has a richer flavor, and the fruit hardness is high. After applying the organic fertilizer of Comparative Examples 1-9 in which the bacterial species components in the microbial agent are changed, the soluble solid content and hardness of the strawberry fruit are reduced to varying degrees, resulting in a significant decrease in the quality of the strawberry fruit.

[0087] It should be noted that the above embodiments are only partial embodiments of the preferred methods of implementing the present invention, rather than all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

Claims

1. A composite microbial organic fertilizer, characterized in that: The invention comprises the following raw materials in parts by weight: 8-12 parts of microbial agents, 30-35 parts of livestock and poultry manure, 20-25 parts of crop straws, 10-15 parts of humic acid, 10-12 parts of bagasse charcoal, 3-5 parts of rumen bypass fat powder, 3-5 parts of molasses and 1-3 parts of chitosan oligosaccharide.

2. The composite microbial organic fertilizer according to claim 1, characterized in that: The microbial agent includes nitrogen-fixing Pseudomonas, long-spored Streptomyces, and polymyxa bacillus; the deposit number of the nitrogen-fixing Pseudomonas is CCTCC S2013531; the deposit number of the long-spored Streptomyces is CCTCC AA 94048; the deposit number of the polymyxa bacillus is CCTCC AB 2013073.

3. The composite microbial organic fertilizer according to claim 1, characterized in that: The preparation method of the microbial agent is as follows: Pseudomonas azotobacter, Streptomyces longisporus, and Paenibacillus polymyxa were cultured in seed culture medium for 48 h, and then inoculated into LB medium at a 5% inoculum volume until the bacterial concentration OD 600 =3.0 to obtain the intermediate bacterial solution, and then mix the three bacterial solutions evenly in a volume ratio of 1:1:1, and freeze-dry them into freeze-dried powder to obtain the microbial agent.

4. The composite microbial organic fertilizer according to claim 1, characterized in that: The preparation method of the bagasse charcoal is: The bagasse is washed with water to remove impurities, and naturally air-dried until the moisture content is less than 15%. The dried bagasse is broken into small pieces of 3-5 cm, and the bagasse is put into a carbonization furnace. The temperature is raised to 400°C at a rate of 10°C / min under anaerobic conditions, and carbonized for 2 hours. The heating is turned off, and inert gas is continued to be introduced for cooling to obtain bagasse charcoal.

5. A method for preparing the composite microbial organic fertilizer according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: (1) Fermentation and decomposition: After the livestock manure and crop straw are ventilated and dried, they are crushed and passed through a 100-mesh sieve, put into a fermentation tank and mixed evenly, water is added to control the moisture content to 50-60%, and then EM bacterial solution is added. The fermentation tank is sealed with a plastic film, and the fermentation process is turned over once every 3 days until the decomposition is complete, and then spread out and aired until the moisture content is ≤40%, thereby obtaining fermented organic matter; (2) preparing microbial agents and bagasse charcoal; (3) Granulation: the microbial agent prepared in step (2) and bagasse charcoal are mixed uniformly, and molasses is added and mixed. After the mixture is uniformly mixed, the fermented organic matter, humic acid and chitosan oligosaccharide prepared in step (1) are added, and the mixture is stirred and mixed uniformly. The mixture is dried to a moisture content of ≤15%, and granulated by a granulator. Particles with a particle size of 3-5 mm are screened out. The particles are placed in a spiral mixer and stirred at a speed of 20-30 r / min. During the stirring process, rumen bypass fat powder is uniformly sprayed onto the particle surface by a sprayer. The mixture is stirred for 10 min to make the fat powder uniformly distributed. The particles are spread out and cooled naturally to obtain composite microbial organic fertilizer particles.

6. The method for preparing the composite microbial organic fertilizer according to claim 5, wherein: The livestock excrement is pig excrement; The crop straw is peanut straw; the added amount of the EM bacterial liquid is 0.1% of the total weight of the excrement and straw.

7. Use of the composite microbial organic fertilizer according to any one of claims 1 to 4 in strawberry planting.

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