Efficient liquid organic fertilizer as well as preparation method and application thereof

Abstract

The invention discloses an efficient liquid organic fertilizer as well as a preparation method and application thereof, and belongs to the technical field of biological organic fertilizers. The liquid organic fertilizer is prepared from the following raw materials in parts by weight: 40 to 50 parts of livestock manure liquid material, 8 to 12 parts of compound microbial agent, 8 to 12 parts of seaweed extract, 6 to 10 parts of soybean meal hydrolysate, 10 to 15 parts of humic acid, 2 to 3 parts of medium trace element chelate, 0.5 to 1 part of chitosan oligosaccharide and 2 to 3 parts of brown sugar. In the compound microbial agent, the nutrient activation capability and the growth regulation function of acinetobacter tanshini and the disease prevention and control of actinoplanes rhizopus cooperate with each other, so that the requirement of cucumber growth on nutrients is met, powdery mildew is effectively prevented and controlled, meanwhile, the soil environment is improved, and the yield and the quality are both improved; the leavening agent is used for completing efficient decomposition conversion of the livestock manure; the two kinds of microbial agents promote each other and have synergistic interaction to form a complete action chain of decomposition-activation-synergism-disease prevention, and finally the application targets of cucumber growth promotion, yield improvement and quality optimization are achieved.

Description

Technical Field

[0001] This invention belongs to the field of bio-organic fertilizer technology, specifically relating to a high-efficiency liquid organic fertilizer, its preparation method, and its application. Background Technology

[0002] As a widely cultivated greenhouse vegetable globally, cucumber yield and quality directly impact growers' economic benefits. However, current cucumber cultivation faces multiple technical bottlenecks: continuous cropping leads to soil compaction and microbial imbalance, preventing the effective absorption of insoluble nutrients such as phosphorus and potassium, resulting in low fertilizer utilization. Simultaneously, cucumber powdery mildew, a prevalent fungal disease, spreads rapidly through air currents, and conventional chemical control methods not only easily lead to fungal resistance but also result in pesticide residues, jeopardizing food safety. Liquid organic fertilizers have gradually become the preferred fertilizer for greenhouse vegetable cultivation due to their advantages such as balanced nutrients, rapid effects, and convenient application. However, existing liquid organic fertilizer products have significant shortcomings: most products rely on a single microbial strain, lacking functional synergy and failing to simultaneously achieve nutrient activation, growth promotion, and disease control; some products use incompletely decomposed poultry and livestock manure as raw materials, and the residual large molecular organic matter can easily cause root burn, while the ammonia, hydrogen sulfide, and other malodorous gases produced during fermentation pollute the environment; in addition, specialized functional liquid organic fertilizers for cucumber powdery mildew are relatively scarce, and existing products mostly focus on nutrient supply with limited disease control effects, failing to meet growers' integrated needs for "fertilizer efficacy + disease prevention".

[0003] Meanwhile, existing fermentation technologies have low degradation efficiency for poultry and livestock manure, resulting in insufficient conversion of macromolecular proteins and cellulose, leading to unstable fertilizer efficacy. Furthermore, the screening of strains for compound microbial agents lacks specificity, failing to establish clear functional divisions and synergistic mechanisms, making it difficult to adapt to the nutritional needs and disease control characteristics of cucumber growth. Therefore, developing a high-efficiency liquid organic fertilizer that can achieve efficient composting of poultry and livestock manure, nutrient activation, growth promotion, and disease control in a synergistic manner, and address current problems in cucumber cultivation such as soil degradation, insufficient fertilizer efficiency, and frequent powdery mildew outbreaks, has become a crucial technological direction that the industry urgently needs to overcome. Summary of the Invention

[0004] The purpose of this invention is to provide a high-efficiency liquid organic fertilizer that achieves efficient composting of poultry and livestock manure, nutrient activation, cucumber growth promotion, and disease control.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows: A high-efficiency liquid organic fertilizer comprises the following raw materials in parts by weight: 40-50 parts of poultry and livestock manure liquid feed, 8-12 parts of compound microbial agent, 8-12 parts of seaweed extract, 6-10 parts of soybean meal hydrolysate, 10-15 parts of humic acid, 2-3 parts of trace element chelates, 0.5-1 part of chitosan oligosaccharide, and 2-3 parts of brown sugar.

[0006] Furthermore, the compound microbial agent includes Acinetobacter tansini and rhizophilic actinomycetes. The Acinetobacter tansini was purchased from the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC 1.9066 and original accession date of January 19, 2009. The rhizophilic actinomycetes was purchased from the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC 4.7133 and original accession date of January 8, 2014.

[0007] Furthermore, the preparation method of the compound microbial agent is as follows: (1) After thawing and activating Acinetobacter tansini, single colonies were picked and inoculated into nutrient broth medium and cultured at 30°C and 180 rpm with shaking until OD reached. 600 =0.6 to obtain seed culture, inoculate 2% into a small seed tank and incubate at 30℃ and 180rpm until the bacterial concentration reaches 1×10. 8 CFU / mL was used to obtain the fermentation broth of Acinetobacter tansini; (2) After thawing and activating the rhizophilic actinomycetes, pick colonies and spores and inoculate them into fresh ISP-2 solid medium. Incubate at 30℃ for 5-7 days until the surface of the medium is covered with hyphae and spores. Wash the spores on the surface of the medium with sterile water and adjust the spore count to 1×10⁻⁶. 7 spores / mL of rhizophilic actinomycete suspension; (3) The fermentation broth of Acinetobacter tansini from step (1) and the spore suspension of rhizophilic actinomycetes from step (2) were mixed at a volume ratio of 1:1 to obtain a compound microbial agent.

[0008] Furthermore, the preparation method of the poultry and livestock manure liquid feed is as follows: Livestock manure is treated at 160-200℃ for 2-3 hours to obtain treated material. The treated material is then mixed with fermentation agent and subjected to aerobic fermentation. After composting, fermented material is obtained. The fermented material is then subjected to solid-liquid separation to obtain liquid livestock manure.

[0009] Furthermore, the mass-to-volume ratio of the poultry and livestock manure treatment material to the fermentation agent is 6 kg: 1 L.

[0010] Furthermore, the fermentation agent includes *Pichia kudriezweig* and *Arthrobacter steudinis*. *Pichia kudriezweig* was purchased from the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC2.5428 and original accession date November 30, 2015; *Arthrobacter steudinis* was purchased from the same center with accession number CGMCC 1.9110 and original accession date April 27, 2009.

[0011] Furthermore, the preparation method of the fermentation agent is as follows: S1: After thawing and activating Pichia pastoris, single colonies were picked and inoculated into malt extract liquid medium and cultured at 28°C and 200 rpm until OD200. 600 =0.6 to obtain seed culture, inoculate the seed culture into a small seed tank at an inoculum rate of 5%, and incubate at 28℃ and 200rpm until the bacterial concentration reaches 1×10⁶. 8 CFU / mL was used to obtain the fermentation broth of Pichia kudriazweis; S2: Thaw and activate *Arthrobacter stearothermiae*, pick a single colony and inoculate it into nutrient broth medium, and incubate at 28°C and 200 rpm until OD500. 600 =0.6 to obtain seed culture, inoculate the seed culture into a small seed tank at an inoculum rate of 5%, and incubate at 28℃ and 200rpm until the bacterial concentration reaches 1×10⁶. 8 CFU / mL was used to obtain the fermentation broth of Arthroblastus stearothermiae; S3: Mix Pichia pastoris fermentation broth and Arthrobacter stenosum fermentation broth at a volume ratio of 1:2 to obtain the fermentation agent.

[0012] Furthermore, the trace chelate comprises EDTA-magnesium, EDTA-iron, and EDTA-zinc in a mass ratio of 10:5:1.

[0013] Furthermore, the preparation method of the soybean meal hydrolysate is as follows: soybean meal and water are mixed at a weight ratio of 1:5, compound protease is added, and the mixture is stirred at 50°C for 4-8 hours. After hydrolysis, the material is heated to 85°C and maintained for 15 minutes. The mixture is then filtered with a filter cloth to obtain a clear soybean meal hydrolysate.

[0014] Furthermore, the amount of the compound protease added is 1% of the weight of soybean meal, and the compound protease includes neutral protease and alkaline protease in a mass ratio of 1:1.

[0015] A method for preparing a high-efficiency liquid organic fertilizer includes the following steps: First, prepare fermentation inoculant, then prepare poultry and livestock manure liquid and compound microbial inoculant; use poultry and livestock manure liquid as base liquid, add seaweed extract, soybean meal hydrolysate and humic acid in sequence while stirring until fully dissolved, then add trace element chelate, chitosan oligosaccharide and brown sugar and stir until completely dissolved, finally add the prepared compound microbial inoculant and stir evenly to obtain high-efficiency liquid organic fertilizer.

[0016] The present invention also provides the application of the high-efficiency liquid organic fertilizer, which is used to promote the growth of cucumbers, increase cucumber yield and quality, and effectively prevent cucumber powdery mildew.

[0017] This invention utilizes fermentation agents to efficiently decompose and transform livestock manure, providing high-quality raw materials for organic fertilizer. *Pichia pastoris*, a fermentation agent, possesses a strong ability to decompose large organic molecules. During the aerobic fermentation of livestock manure, it can rapidly degrade insoluble substances such as proteins and cellulose, converting them into smaller molecules easily absorbed by plants. Simultaneously, it decomposes nitrogenous organic matter (such as ammonia nitrogen precursors) in the manure, reducing the production of odorous gases such as ammonia and hydrogen sulfide during fermentation and improving the production environment. *Arthrobacter stenosum* has a powerful enzyme system capable of degrading intractable proteins, keratin, and fats in manure, converting large organic molecules into smaller molecules and improving the fertilizer efficiency of subsequent liquid fertilizers. *Arthrobacter stenosum* can metabolize odor-producing substrates such as sulfur-containing amino acids, working synergistically with yeast to achieve a more thorough deodorization effect. *Arthrobacter steudinis* exhibits strong environmental adaptability in aerobic fermentation, tolerating the high organic matter and high ammonia nitrogen environment in the early stages of manure fermentation. It continuously decomposes residual complex organic matter, promoting complete manure decomposition and preventing root burn damage to crops from uncooked materials. Simultaneously, its metabolically produced antibacterial substances inhibit the reproduction of harmful pathogens (such as *E. coli*) in manure, reducing the content of harmful microorganisms in organic fertilizer and improving product safety. The combination of *Pichia pastoris* and *Arthrobacter steudinis* ensures that livestock manure liquid meets quality standards of being fully decomposed, odorless, rich in soluble organic nutrients, and low in pathogen risk, providing a high-quality base liquid for finished fertilizer.

[0018] Compound microbial inoculants effectively enhance the fertilizer efficiency of organic fertilizers, promote crop growth, and strengthen disease resistance. *Acinetobacter tansini* can convert insoluble phosphates in the soil into forms that can be absorbed by plants; simultaneously, its metabolically produced indoleacetic acid stimulates cucumber root growth, increases root surface area, and enhances the plant's ability to absorb water and nutrients. *Acinetobacter tansini* can rapidly multiply in the soil and form a dominant bacterial community, acting as a beneficial bacterial barrier and improving the soil's microecological balance. *Rhizotrophic actinomycetes* are key strains for controlling cucumber powdery mildew; their metabolically produced antibiotics directly inhibit spore germination and mycelial growth of powdery mildew fungi, destroying the fungal cell structure and blocking disease transmission at its source; simultaneously, they can induce systemic resistance in cucumber plants, enhancing the plant's own immunity and strengthening its resistance to subsequent powdery mildew infection. Acinetobacter tansii and rhizotrophic actinomycetes work synergistically to promote the elongation of cucumber stems and vines, thicken leaves, improve photosynthetic efficiency, and increase dry matter accumulation. At the same time, they promote the synthesis of vitamin C and soluble sugars in cucumber fruits, reduce nitrate content, and improve the taste and nutritional value of cucumbers, thus achieving a dual improvement in yield and quality.

[0019] Beneficial effects In compound microbial agents, the nutrient activation ability and growth regulation function of Acinetobacter tansini and the disease control function of rhizophilic actinomycetes work synergistically to meet the nutrient requirements of cucumber growth, effectively control powdery mildew, improve the soil environment, and achieve a dual improvement in yield and quality. The compound microbial agent and fermentation agent used in this invention promote each other and work synergistically to form a complete chain of action of "composting-activation-enhancement-disease prevention", ultimately achieving the application goals of promoting cucumber growth, increasing yield and optimizing quality. Detailed Implementation

[0020] The technical solution of the present invention will be further described below with reference to specific embodiments, but it is not limited thereto.

[0021] Example 1 A high-efficiency liquid organic fertilizer comprises the following raw materials in parts by weight: 40 parts of poultry and livestock manure liquid feed, 8 parts of compound microbial agent, 8 parts of seaweed extract, 6 parts of soybean meal hydrolysate, 10 parts of humic acid, 2 parts of trace element chelates, 0.5 parts of chitosan oligosaccharide, and 2 parts of brown sugar.

[0022] The compound microbial agent includes Acinetobacter tansini and rhizophilic actinomycetes. The Acinetobacter tansini has the accession number CGMCC 1.9066, and the rhizophilic actinomycetes has the accession number CGMCC 4.7133.

[0023] The preparation method of the composite microbial agent is as follows: (1) After thawing and activating Acinetobacter tansini, single colonies were picked and inoculated into nutrient broth medium and cultured at 30°C and 180 rpm with shaking until OD reached. 600 =0.6 to obtain seed culture, inoculate 2% into a small seed tank and incubate at 30℃ and 180rpm until the bacterial concentration reaches 1×10. 8 CFU / mL was used to obtain the fermentation broth of Acinetobacter tansini; (2) After thawing and activating the rhizophilic actinomycetes, pick colonies and spores and inoculate them into fresh ISP-2 solid medium. Incubate at 30℃ for 5-7 days until the surface of the medium is covered with hyphae and spores. Wash the spores on the surface of the medium with sterile water and adjust the spore count to 1×10⁻⁶. 7 spores / mL of rhizophilic actinomycete suspension; (3) The fermentation broth of Acinetobacter tansini from step (1) and the spore suspension of rhizophilic actinomycetes from step (2) were mixed at a volume ratio of 1:1 to obtain a compound microbial agent.

[0024] The preparation method of the poultry and livestock manure liquid feed is as follows: Livestock manure was treated at 160℃ for 3 hours to obtain treated material. The treated material was then mixed with fermentation agent and subjected to aerobic fermentation. After composting, fermented material was obtained. The fermented material was then subjected to solid-liquid separation to obtain liquid livestock manure.

[0025] The mass-to-volume ratio of the poultry and livestock manure treatment material to the fermentation agent is 6 kg: 1 L.

[0026] The fermentation agents include Pichia kudriezweig and Arthrobacter stevia, with the Pichia kudriezweig preservation number being CGMCC2.5428 and the Arthrobacter stevia preservation number being CGMCC1.9110.

[0027] The preparation method of the fermentation agent is as follows: S1: After thawing and activating Pichia pastoris, single colonies were picked and inoculated into malt extract liquid medium and cultured at 28°C and 200 rpm until OD200. 600 =0.6 to obtain seed culture, inoculate the seed culture into a small seed tank at an inoculum rate of 5%, and incubate at 28℃ and 200rpm until the bacterial concentration reaches 1×10⁶. 8 CFU / mL was used to obtain the fermentation broth of Pichia kudriazweis; S2: Thaw and activate *Arthrobacter stearothermiae*, pick a single colony and inoculate it into nutrient broth medium, and incubate at 28°C and 200 rpm until OD500. 600 =0.6 to obtain seed culture, inoculate the seed culture into a small seed tank at an inoculum rate of 5%, and incubate at 28℃ and 200rpm until the bacterial concentration reaches 1×10⁶. 8 CFU / mL was used to obtain the fermentation broth of Arthroblastus stearothermiae; S3: Mix Pichia pastoris fermentation broth and Arthrobacter stenosum fermentation broth at a volume ratio of 1:2 to obtain the fermentation agent.

[0028] The trace chelate comprises EDTA-magnesium, EDTA-iron, and EDTA-zinc in a mass ratio of 10:5:1.

[0029] The preparation method of the soybean meal hydrolysate is as follows: Soybean meal and water are mixed at a weight ratio of 1:5, compound protease is added, and the mixture is stirred at 50°C for 4 hours. After hydrolysis, the material is heated to 85°C and maintained for 15 minutes. The mixture is then filtered with a filter cloth to obtain a clear soybean meal hydrolysate.

[0030] The amount of the compound protease added is 1% of the weight of soybean meal, and the compound protease includes neutral protease and alkaline protease in a mass ratio of 1:1.

[0031] A method for preparing a high-efficiency liquid organic fertilizer includes the following steps: First, prepare fermentation inoculant, then prepare poultry and livestock manure liquid and compound microbial inoculant; use poultry and livestock manure liquid as base liquid, add seaweed extract, soybean meal hydrolysate and humic acid in sequence while stirring until fully dissolved, then add trace element chelate, chitosan oligosaccharide and brown sugar and stir until completely dissolved, finally add the prepared compound microbial inoculant and stir evenly to obtain high-efficiency liquid organic fertilizer.

[0032] Example 2 A high-efficiency liquid organic fertilizer comprises the following raw materials in parts by weight: 45 parts of poultry and livestock manure liquid feed, 10 parts of compound microbial agent, 10 parts of seaweed extract, 8 parts of soybean meal hydrolysate, 13 parts of humic acid, 2 parts of trace element chelate, 1 part of chitosan oligosaccharide, and 3 parts of brown sugar.

[0033] The compound microbial agent includes Acinetobacter tansini and rhizophilic actinomycetes. The Acinetobacter tansini has the accession number CGMCC 1.9066, and the rhizophilic actinomycetes has the accession number CGMCC 4.7133.

[0034] The preparation method of the composite microbial agent is as follows: (1) After thawing and activating Acinetobacter tansini, single colonies were picked and inoculated into nutrient broth medium and cultured at 30°C and 180 rpm with shaking until OD reached. 600 =0.6 to obtain seed culture, inoculate 2% into a small seed tank and incubate at 30℃ and 180rpm until the bacterial concentration reaches 1×10. 8 CFU / mL was used to obtain the fermentation broth of Acinetobacter tansini; (2) After thawing and activating the rhizophilic actinomycetes, pick colonies and spores and inoculate them into fresh ISP-2 solid medium. Incubate at 30℃ for 5-7 days until the surface of the medium is covered with hyphae and spores. Wash the spores on the surface of the medium with sterile water and adjust the spore count to 1×10⁻⁶. 7 spores / mL of rhizophilic actinomycete suspension; (3) The fermentation broth of Acinetobacter tansini from step (1) and the spore suspension of rhizophilic actinomycetes from step (2) were mixed at a volume ratio of 1:1 to obtain a compound microbial agent.

[0035] The preparation method of the poultry and livestock manure liquid feed is as follows: Livestock manure was treated at 180℃ for 2.5 hours to obtain treated material. The treated material was then mixed with fermentation agent and subjected to aerobic fermentation. After composting, fermented material was obtained. The fermented material was then subjected to solid-liquid separation to obtain liquid livestock manure.

[0036] The mass-to-volume ratio of the poultry and livestock manure treatment material to the fermentation agent is 6 kg: 1 L.

[0037] The fermentation agents include Pichia kudriezweig and Arthrobacter stevia, with the Pichia kudriezweig preservation number being CGMCC2.5428 and the Arthrobacter stevia preservation number being CGMCC1.9110.

[0038] The preparation method of the fermentation agent is as follows: S1: After thawing and activating Pichia pastoris, single colonies were picked and inoculated into malt extract liquid medium and cultured at 28°C and 200 rpm until OD200. 600 =0.6 to obtain seed culture, inoculate the seed culture into a small seed tank at an inoculum rate of 5%, and incubate at 28℃ and 200rpm until the bacterial concentration reaches 1×10⁶. 8 CFU / mL was used to obtain the fermentation broth of Pichia kudriazweis; S2: Thaw and activate *Arthrobacter stearothermiae*, pick a single colony and inoculate it into nutrient broth medium, and incubate at 28°C and 200 rpm until OD500. 600 =0.6 to obtain seed culture, inoculate the seed culture into a small seed tank at an inoculum rate of 5%, and incubate at 28℃ and 200rpm until the bacterial concentration reaches 1×10⁶. 8 CFU / mL was used to obtain the fermentation broth of Arthroblastus stearothermiae; S3: Mix Pichia pastoris fermentation broth and Arthrobacter stenosum fermentation broth at a volume ratio of 1:2 to obtain the fermentation agent.

[0039] The trace chelate comprises EDTA-magnesium, EDTA-iron, and EDTA-zinc in a mass ratio of 10:5:1.

[0040] The preparation method of the soybean meal hydrolysate is as follows: Soybean meal and water are mixed at a weight ratio of 1:5, compound protease is added, and the mixture is stirred at 50°C for 6 hours. After hydrolysis, the material is heated to 85°C and maintained for 15 minutes. The mixture is then filtered with a filter cloth to obtain a clear soybean meal hydrolysate.

[0041] The amount of the compound protease added is 1% of the weight of soybean meal, and the compound protease includes neutral protease and alkaline protease in a mass ratio of 1:1.

[0042] A method for preparing a high-efficiency liquid organic fertilizer includes the following steps: First, prepare fermentation inoculant, then prepare poultry and livestock manure liquid and compound microbial inoculant; use poultry and livestock manure liquid as base liquid, add seaweed extract, soybean meal hydrolysate and humic acid in sequence while stirring until fully dissolved, then add trace element chelate, chitosan oligosaccharide and brown sugar and stir until completely dissolved, finally add the prepared compound microbial inoculant and stir evenly to obtain high-efficiency liquid organic fertilizer.

[0043] Example 3 A high-efficiency liquid organic fertilizer comprises the following raw materials in parts by weight: 50 parts of poultry and livestock manure liquid feed, 12 parts of compound microbial agent, 12 parts of seaweed extract, 10 parts of soybean meal hydrolysate, 15 parts of humic acid, 3 parts of trace element chelate, 1 part of chitosan oligosaccharide, and 3 parts of brown sugar.

[0044] The compound microbial agent includes Acinetobacter tansini and rhizophilic actinomycetes. The Acinetobacter tansini has the accession number CGMCC 1.9066, and the rhizophilic actinomycetes has the accession number CGMCC 4.7133.

[0045] The preparation method of the composite microbial agent is as follows: (1) After thawing and activating Acinetobacter tansini, single colonies were picked and inoculated into nutrient broth medium and cultured at 30°C and 180 rpm with shaking until OD reached. 600 =0.6 to obtain seed culture, inoculate 2% into a small seed tank and incubate at 30℃ and 180rpm until the bacterial concentration reaches 1×10. 8 CFU / mL was used to obtain the fermentation broth of Acinetobacter tansini; (2) After thawing and activating the rhizophilic actinomycetes, pick colonies and spores and inoculate them into fresh ISP-2 solid medium. Incubate at 30℃ for 5-7 days until the surface of the medium is covered with hyphae and spores. Wash the spores on the surface of the medium with sterile water and adjust the spore count to 1×10⁻⁶. 7 spores / mL of rhizophilic actinomycete suspension; (3) The fermentation broth of Acinetobacter tansini from step (1) and the spore suspension of rhizophilic actinomycetes from step (2) were mixed at a volume ratio of 1:1 to obtain a compound microbial agent.

[0046] The preparation method of the poultry and livestock manure liquid feed is as follows: Livestock manure is treated at 200℃ for 2 hours to obtain treated material. The treated material is then mixed with fermentation agent and subjected to aerobic fermentation. After composting, fermented material is obtained. The fermented material is then subjected to solid-liquid separation to obtain liquid livestock manure.

[0047] The mass-to-volume ratio of the poultry and livestock manure treatment material to the fermentation agent is 6 kg: 1 L.

[0048] The fermentation agents include Pichia kudriezweig and Arthrobacter stevia, with the Pichia kudriezweig preservation number being CGMCC2.5428 and the Arthrobacter stevia preservation number being CGMCC1.9110.

[0049] The preparation method of the fermentation agent is as follows: S1: After thawing and activating Pichia pastoris, single colonies were picked and inoculated into malt extract liquid medium and cultured at 28°C and 200 rpm until OD200. 600 =0.6 to obtain seed culture, inoculate the seed culture into a small seed tank at an inoculum rate of 5%, and incubate at 28℃ and 200rpm until the bacterial concentration reaches 1×10⁶. 8 CFU / mL was used to obtain the fermentation broth of Pichia kudriazweis; S2: Thaw and activate *Arthrobacter stearothermiae*, pick a single colony and inoculate it into nutrient broth medium, and incubate at 28°C and 200 rpm until OD500. 600 =0.6 to obtain seed culture, inoculate the seed culture into a small seed tank at an inoculum rate of 5%, and incubate at 28℃ and 200rpm until the bacterial concentration reaches 1×10⁶. 8 CFU / mL was used to obtain the fermentation broth of Arthroblastus stearothermiae; S3: Mix Pichia pastoris fermentation broth and Arthrobacter stenosum fermentation broth at a volume ratio of 1:2 to obtain the fermentation agent.

[0050] The trace chelate comprises EDTA-magnesium, EDTA-iron, and EDTA-zinc in a mass ratio of 10:5:1.

[0051] The preparation method of the soybean meal hydrolysate is as follows: Soybean meal and water are mixed at a weight ratio of 1:5, compound protease is added, and the mixture is stirred at 50°C for 8 hours. After hydrolysis, the material is heated to 85°C and maintained for 15 minutes. The mixture is then filtered with a filter cloth to obtain a clear soybean meal hydrolysate.

[0052] The amount of the compound protease added is 1% of the weight of soybean meal, and the compound protease includes neutral protease and alkaline protease in a mass ratio of 1:1.

[0053] A method for preparing a high-efficiency liquid organic fertilizer includes the following steps: First, prepare fermentation inoculant, then prepare poultry and livestock manure liquid and compound microbial inoculant; use poultry and livestock manure liquid as base liquid, add seaweed extract, soybean meal hydrolysate and humic acid in sequence while stirring until fully dissolved, then add trace element chelate, chitosan oligosaccharide and brown sugar and stir until completely dissolved, finally add the prepared compound microbial inoculant and stir evenly to obtain high-efficiency liquid organic fertilizer.

[0054] Comparative Example 1 Compared with Example 3, this comparative example is identical to Example 3 except that the fermentation broth of Pichia pastoris and Arthrobacter stenosum were prepared in a 1:1 volume ratio during the preparation of the fermentation agent. All other raw materials and steps are the same as in Example 3.

[0055] Comparative Example 2 Compared with Example 3, this comparative example uses only Pichia pastoris fermentation broth in the preparation of the fermentation agent, while the other raw materials and steps are the same as in Example 3.

[0056] Comparative Example 3 Compared with Example 3, this comparative example uses only Bacillus stenosum fermentation broth in the preparation of the fermentation agent, while the other raw materials and steps are the same as in Example 3.

[0057] Comparative Example 4 Compared with Example 3, this comparative example uses the same raw materials and steps as Example 3, except that the compound microbial agent only uses Acinetobacter tansini.

[0058] Comparative Example 5 Compared with Example 3, this comparative example uses the same raw materials and steps as Example 3, except that the compound microbial agent only uses rhizophilic actinomycetes.

[0059] Comparative Example 6 Compared with Example 3, this comparative example uses the same raw materials and steps as Example 3, except that only EM bacteria are used for fermentation in the preparation of poultry and livestock manure liquid material.

[0060] Performance testing The cucumber variety used in the experiment was Cucumber No. 8. The experiment was conducted in a solar greenhouse in early spring. The soil physicochemical properties of the topsoil (0-20cm) at room temperature were as follows: pH 8.02, organic matter content 21.7 g / kg, total salt content 2.26 g / kg, total nitrogen 1.58 g / kg, available nitrogen 112.45 mg / kg, available phosphorus 71.2 mg / kg, and available potassium 154.3 mg / kg.

[0061] The experiment consisted of 10 treatment groups: no fertilizer (CK), liquid organic fertilizer prepared in Examples 1-3, and Comparative Examples 1-6. Each treatment group had 3 replicates, and each plot was 15 m². 2 Planting spacing was 40cm × 80cm, with 50 plants per plot. Plots were randomly assigned to blocks. Liquid fertilizer was applied every 15 days for a total of four applications: root application, foliar spray, root application, and root application again. The liquid organic fertilizer prepared for each treatment group was diluted 300 times before use. Root application was done at a rate of 5L per acre, and foliar spraying was done until water droplets fell from the leaves. The control group (CK) used water instead of fertilizer for each application. All other management practices were the same. Single fruit weight and plot yield were recorded, and the yield increase rate was calculated.

[0062] Once the disease incidence rate of the blank control (ck) reaches 80% or higher, a graded survey of the disease incidence in each treatment group will be conducted, with 5 plants surveyed at each site. The disease grade grading criteria are as follows: Level 0: No disease; Grade 1: The area of ​​lesions accounts for less than 5% of the total leaf area; Grade 3: The area of ​​lesions accounts for less than 5% to 15% of the total leaf area; Level 5: The area of ​​lesions accounts for less than 15% to 25% of the total leaf area; Level 7: The area of ​​lesions accounts for less than 25% to 50% of the total leaf area; Level 9: The area of ​​lesions accounts for less than 50% to 75% of the total leaf area; Level 11: The lesion area accounts for more than 75% of the total leaf area; Disease index = Σ(Disease grade × Number of plants at that disease grade) / (Highest disease grade × Total number of plants) × 100% Prevention efficacy = (disease index of control group - disease index of treatment group) / disease index of control group × 100%; The above statistical results are shown in Table 1.

[0063] Table 1. Cucumber yield and disease efficacy under different treatments As shown in Table 1, compared with the control (CK), the use of the liquid organic fertilizer from Examples 1-3 of this invention significantly increased the weight of cucumber fruits and yield, with yield increases exceeding 20%. Simultaneously, cucumber powdery mildew was significantly reduced, with a control effect exceeding 80%. However, after changing the composition of the compound microbial agent, compared with Example 3, the synergistic effect of the two bacteria in Comparative Examples 4 and 5 disappeared, significantly reducing the control effect of powdery mildew, and both fruit weight and yield decreased to varying degrees. Furthermore, after changing the composition of the fermentation agent, as shown in Comparative Examples 1-3, the fermentation effect of the fermentation agent on poultry and livestock manure decreased, reducing the effectiveness of the liquid fertilizer and consequently leading to a decrease in fruit weight and yield.

[0064] After the cucumbers were harvested, 10 cucumbers were randomly selected from each treatment group. Soluble sugar was determined by anthrone colorimetric method, vitamin C was determined by spectrophotometry, soluble solids content was determined by PAL-1 handheld refractometer, and nitrate was determined by ion chromatography. The statistical results are shown in Table 2.

[0065] Table 2. Quality of cucumbers under different treatments As shown in Table 2, compared with the control group (CK), the soluble sugar content and vitamin C content of cucumbers were significantly increased and the nitrate content was significantly reduced after using the liquid organic fertilizer of Examples 1-3 of this invention. This indicates that the liquid organic fertilizer of this invention can effectively improve the quality of cucumbers.

[0066] It should be noted that the above embodiments are merely some preferred embodiments of the present invention, and not all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

Claims

1. A high-efficiency liquid organic fertilizer, characterized in that, The raw materials include the following parts by weight: 40-50 parts of poultry and livestock manure liquid feed, 8-12 parts of compound microbial agent, 8-12 parts of seaweed extract, 6-10 parts of soybean meal hydrolysate, 10-15 parts of humic acid, 2-3 parts of trace element chelate, 0.5-1 part of chitosan oligosaccharide, and 2-3 parts of brown sugar.

2. The high-efficiency liquid organic fertilizer according to claim 1, characterized in that, The compound microbial agent includes Acinetobacter tansini and rhizophilic actinomycetes. The preservation number of Acinetobacter tansini is CGMCC 1.9066, and the preservation number of rhizophilic actinomycetes is CGMCC 4.7133.

3. The high-efficiency liquid organic fertilizer according to claim 1, characterized in that, The preparation method of the composite microbial agent is as follows: (1) After thawing and activating Acinetobacter tansini, single colonies were picked and inoculated into nutrient broth medium and cultured at 30°C and 180 rpm with shaking until OD reached. 600 =0.6 to obtain seed culture, inoculate 2% into a small seed tank and incubate at 30℃ and 180rpm until the bacterial concentration reaches 1×10. 8 CFU / mL was used to obtain the fermentation broth of Acinetobacter tansini; (2) After thawing and activating the rhizophilic actinomycetes, pick colonies and spores and inoculate them into fresh ISP-2 solid medium. Incubate at 30℃ for 5-7 days until the surface of the medium is covered with hyphae and spores. Wash the spores on the surface of the medium with sterile water and adjust the spore count to 1×10⁻⁶. 7 A suspension of rhizophilic actinomycete spores per mL; (3) The fermentation broth of Acinetobacter tansini from step (1) and the spore suspension of rhizophilic actinomycetes from step (2) were mixed at a volume ratio of 1:1 to obtain a compound microbial agent.

4. The high-efficiency liquid organic fertilizer according to claim 1, characterized in that, The preparation method of the poultry and livestock manure liquid feed is as follows: Livestock manure is treated at 160-200℃ for 2-3 hours to obtain treated material. The treated material is then mixed with fermentation agent and subjected to aerobic fermentation. After composting, fermented material is obtained. The fermented material is then subjected to solid-liquid separation to obtain liquid livestock manure.

5. The high-efficiency liquid organic fertilizer according to claim 4, characterized in that, The mass-to-volume ratio of the poultry and livestock manure treatment material to the fermentation agent is 6 kg: 1 L.

6. The high-efficiency liquid organic fertilizer according to claim 4, characterized in that, The fermentation agents include Pichia kudriezweig and Arthrobacter stevia. The preservation number of Pichia kudriezweig is CGMCC2.5428, and the preservation number of Arthrobacter stevia is CGMCC1.9110.

7. The high-efficiency liquid organic fertilizer according to claim 4, characterized in that, The preparation method of the fermentation agent is as follows: S1: After thawing and activating *Pichia pastoris*, single colonies were picked and inoculated into malt extract liquid medium and cultured at 28°C and 200 rpm until OD500. 600 =0.6 to obtain seed culture, inoculate the seed culture into a small seed tank at an inoculum rate of 5%, and incubate at 28℃ and 200rpm until the bacterial concentration reaches 1×10⁶. 8 CFU / mL was used to obtain the fermentation broth of Pichia kudriazweis; S2: Thaw and activate *Arthrobacter stearothermiae*, pick a single colony and inoculate it into nutrient broth medium, and incubate at 28°C and 200 rpm until OD500. 600 =0.6 to obtain seed culture, inoculate the seed culture into a small seed tank at an inoculum rate of 5%, and incubate at 28℃ and 200rpm until the bacterial concentration reaches 1×10⁶. 8 CFU / mL was used to obtain the fermentation broth of Arthroblastus stearothermiae; S3: Mix Pichia pastoris fermentation broth and Arthrobacter stenosum fermentation broth at a volume ratio of 1:2 to obtain the fermentation agent.

8. The high-efficiency liquid organic fertilizer according to claim 1, characterized in that, The trace chelate comprises EDTA-magnesium, EDTA-iron, and EDTA-zinc in a mass ratio of 10:5:

1.

9. A method for preparing the high-efficiency liquid organic fertilizer according to any one of claims 1-8, characterized in that, Includes the following steps: First, prepare fermentation inoculant, then prepare poultry and livestock manure liquid and compound microbial inoculant; use poultry and livestock manure liquid as base liquid, add seaweed extract, soybean meal hydrolysate and humic acid in sequence while stirring until fully dissolved, then add trace element chelate, chitosan oligosaccharide and brown sugar and stir until completely dissolved, finally add the prepared compound microbial inoculant and stir evenly to obtain high-efficiency liquid organic fertilizer.

10. The application of the high-efficiency liquid organic fertilizer according to claim 1, characterized in that, The high-efficiency liquid organic fertilizer is used to promote cucumber growth, increase cucumber yield and quality, and effectively prevent cucumber powdery mildew.

Images