Special alkaline bio-organic fertilizer for banana and preparation method thereof

Abstract

This invention discloses a banana-specific alkaline biocontrol organic fertilizer and its preparation method, belonging to the field of bio-organic fertilizer technology. The banana-specific alkaline biocontrol organic fertilizer of this invention comprises the following raw materials: 25-30 parts modified tobacco straw carbonized powder, 20-25 parts moringa seed fermentation product, 5-10 parts cactus fermentation product, 10-14 parts seaweed residue, 8-12 parts humic acid powder, and 3-5 parts shell powder. The moringa seeds are fermented using enzymatic hydrolysis and microbial agents, effectively breaking down large molecules into smaller molecules that can be directly absorbed by banana plants, promoting plant growth. Simultaneously, *Achromobacterium solani* and *Acinetobacter rhizogenes* secrete various active substances, significantly enhancing banana disease resistance and growth promotion. This invention's organic fertilizer, with its synergistic effect of multiple substances, reduces the use of chemical fungicides, effectively inhibits banana wilt disease, neutralizes soil acidity, increases banana yield, and improves economic and social benefits.

Description

Technical Field

[0001] This invention belongs to the field of bio-organic fertilizer technology, specifically relating to a banana-specific alkaline biocontrol organic fertilizer and its preparation method. Background Technology

[0002] Bananas are large, perennial herbaceous fruit trees and are one of the important economic crops in tropical and subtropical regions, playing a vital role in agricultural economic development. Bananas are perennial with a large biomass, grow rapidly, and have a high demand for nutrients, with nutrient absorption and utilization exhibiting distinct stages and seasonality.

[0003] In recent years, the problem of excessive fertilizer application in banana production has become increasingly prominent. Large and frequent applications of fertilizers have led to a series of problems, including low fertilizer utilization, high production costs, declining fruit quality, soil compaction and acidification, severe soil-borne diseases, and environmental pollution. Furthermore, due to the high economic value of bananas, fertilizer application has increased year by year, and the long-term use of acidic or physiologically acidic fertilizers has exacerbated soil acidification in banana plantations. Soil acidification not only damages soil structure, reduces soil fertility, and decreases soil microbial diversity and activity, but also promotes the germination and damage of Fusarium oxysporum, causing outbreaks of banana wilt disease, resulting in reduced yields or even crop failure. The occurrence and spread of banana wilt disease severely restricts the development of the banana industry. Banana wilt disease is a typical soil-borne disease caused by Fusarium oxysporum (specific strain Cubanae). It is prone to outbreaks in acidic environments, and conventional chemical agents are difficult to exert a sustained control effect. Soil fumigation and crop rotation also have very limited effectiveness. However, when the soil pH is significantly increased, the wilt disease index in bananas decreases significantly.

[0004] Replacing chemical fertilizers with organic fertilizers is a crucial way to achieve zero growth in chemical fertilizer use. This is primarily achieved through methods such as applying livestock and poultry manure, returning straw to the field, planting green manure, and using novel functional fertilizers. New compound microbial fertilizers, with their growth-promoting, biocontrol, and abiotic stress-resistance functions, are receiving increasing attention in research on reducing chemical fertilizer input. However, comprehensive evaluations of the impacts of novel organic fertilizers, especially alkaline organic fertilizers that increase soil pH, on soil properties, crop growth, yield, resistance to banana wilt disease, and economic benefits are limited. Research on the combined effects of functional organic fertilizers and facility irrigation on tropical cash crops like bananas is particularly lacking. Therefore, exploring novel biocontrol organic fertilizers is especially important for controlling banana diseases and increasing banana yield. Summary of the Invention

[0005] The purpose of this invention is to provide a special alkaline biocontrol organic fertilizer for bananas, which can effectively prevent banana wilt disease, neutralize soil acidity, and increase banana yield.

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

[0007] A banana-specific alkaline biocontrol organic fertilizer is prepared from the following raw materials in parts by weight: 25-30 parts modified tobacco straw carbonized powder, 20-25 parts moringa seed fermentation product, 5-10 parts cactus fermentation product, 10-14 parts seaweed residue, 8-12 parts humic acid powder, and 3-5 parts shell powder.

[0008] Furthermore, the pH value of the biocontrol organic fertilizer is greater than 8.0.

[0009] Furthermore, the preparation method of the moringa seed ferment is as follows:

[0010] Step S1: After drying moringa seeds, pulverize them to obtain moringa seed powder. Add a compound hydrolytic enzyme solution containing papain and cellulase, and hydrolyze at 45-55℃ for 4-6 hours. Inactivate at high temperature, cool to room temperature, and set the mixture aside.

[0011] Step S2: Add Achromobacterium sol and Acinetobacter ghurtianum to the mixture and ferment at 30°C for 24-48 hours to obtain Moringa seed ferment.

[0012] Furthermore, in step S1 of the method for preparing moringa seed ferment, the mass-to-volume ratio of moringa seed powder to compound hydrolytic enzyme solution is 1 kg: 2 L.

[0013] Furthermore, the complex hydrolytic enzyme solution contains 15-18 g / L of papain and 10-14 g / L of cellulase.

[0014] Furthermore, in step S2 of the method for preparing Moringa seed fermentation, Achromobacterium sol-gel was purchased from the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC1.4514 and original accession date of June 27, 2005; Acinetobacter Gastroenteritis was purchased from the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC1.15884 and original accession date of September 20, 2016; the amount of Achromobacterium sol-gel added was 18-22 g / L, and the amount of Acinetobacter Gastroenteritis added was 25-30 g / L.

[0015] Furthermore, the preparation method of Achromobacterium sol-gel and Acinetobacter ghurriformis is as follows: single colonies of Achromobacterium sol-gel and Acinetobacter ghurriformis are picked and inoculated into LB liquid medium, and cultured at 30°C and 200 r / min until OD. 600 =0.6 to obtain seed culture, and inoculate the seed culture at a rate of 1% into 5LLB liquid medium and culture at 30℃ and 200 r / min until the viable count of Achromobacterium solani is greater than 1×10. 10 CFU / mL, culture of Acinetobacter griseus greater than 2 × 10⁻⁶ 10CFU / mL, the bacterial sludge was collected by centrifugation, and trehalose, skim milk and ascorbic acid were added to prepare lyophilized powder. The viable counts of Achromobacterium sol and Acinetobacter griseus were then detected.

[0016] Furthermore, the viable count of the achromobacterium sol is 10 billion / g, and the viable count of Acinetobacter ghurterii is 20 billion / g.

[0017] Furthermore, the preparation method of the modified tobacco straw carbonized powder is as follows:

[0018] Waste tobacco straw was washed, dried, and pulverized through a 100-mesh sieve. It was then placed in a reaction vessel, and nitrogen gas was introduced to purge the air. The mixture was carbonized at 500°C for 2 hours. After carbonization, it was cooled to room temperature. The carbonized powder was then soaked in a 5% calcium hydroxide solution and stirred for 2-3 hours. After filtration, it was dried. The carbonized powder was then mixed with magnesium oxide and calcined at 400°C for 1.5 hours. Finally, it was stirred in a 10% urea-formaldehyde-nitrogen solution at 60°C for 2 hours and then dried to obtain modified tobacco straw carbonized powder.

[0019] Furthermore, the preparation method of urea-formaldehyde nitrogen solution is as follows: formaldehyde solution is mixed with 60% of total urea, sodium hydroxide solution is added to adjust the pH to 8-9, and the mixture is reacted in a water bath at 60-80℃ for 1 hour. The remaining urea is slowly added, the mixture is allowed to cool naturally to 50℃, and the reaction continues for 30-60 minutes until the viscosity reaches a syrupy state, thus obtaining urea-formaldehyde nitrogen solution. The molar ratio of urea to formaldehyde is 1:1.5-2.0, and the formaldehyde solution is a 37% aqueous formaldehyde solution.

[0020] Furthermore, in the preparation method of the modified tobacco straw carbonized powder, the solid-liquid ratio of carbonized powder, magnesium oxide, 5% calcium hydroxide solution and 10% urea-formaldehyde nitrogen solution is 100g:15g:500mL:400mL.

[0021] A method for preparing an alkaline biocontrol organic fertilizer specifically for bananas includes the following steps:

[0022] (1) After slicing fresh cactus, dry it at 60℃ with a moisture content of less than 10%, crush it through a 60-mesh sieve to remove fiber clumps, adjust the moisture content to 50-55%, add EM bacteria to ferment for 7 days, spread it out to dry until the moisture content is less than 20%, and obtain cactus fermented product.

[0023] (2) Mix the modified tobacco straw carbonization powder, humic acid powder and shell powder evenly, add moringa seed ferment, cactus ferment and seaweed residue, and stir until there are no lumps to obtain the mixture.

[0024] (3) The mixture is granulated using a disc granulator, 5% water is sprayed in to assist in the molding, and particles with a diameter of 2-4 mm are screened out. The mixture is dried at 50°C until the moisture content is less than 10% to obtain the final product, alkaline biocontrol organic fertilizer.

[0025] All raw materials used in this invention are commercially available.

[0026] Modified tobacco straw charcoal made from shell powder and calcium hydroxide can neutralize acidic soils, making it especially suitable for banana plantations acidified by long-term application of chemical fertilizers. The modified tobacco straw charcoal powder, rich in magnesium oxide, further enhances its alkalinity-regulating ability, promoting the absorption of micronutrients such as calcium and magnesium by bananas and preventing magnesium deficiency-induced yellow leaf disease. High-temperature carbonization of the modified tobacco straw charcoal powder creates a porous structure, with calcium hydroxide and magnesium oxide loaded in the pores slowly releasing alkaline substances. The slow-release nitrogen source from urea-formaldehyde nitrogen solution reduces nutrient loss. Furthermore, the nicotine-containing compounds in the tobacco straw charcoal powder have a certain inhibitory effect on fungal diseases.

[0027] This invention introduces a biocontrol organic fertilizer with added Moringa seeds. During the fermentation process, it produces a variety of natural active substances that enhance root development, improve nutrient absorption, and release nutrients to increase fertilizer efficiency. In addition, its antioxidant components can alleviate oxidative stress in plants and enhance their resistance to acidic soil stress.

[0028] This invention screened two microbial strains that not only accelerate the decomposition of Moringa seeds but also secrete various active substances. Specifically, *Acinetobacter griseus* secretes indoleacetic acid and potassium-solubilizing agents, while *Achromobacter solani* produces siderophores. Furthermore, both strains exhibit antagonistic effects against banana wilt disease, and the inhibitory effect is optimal when both strains are used simultaneously. The combined use of these two strains, working synergistically, significantly enhances disease resistance and promotes growth.

[0029] Beneficial effects

[0030] This invention relates to an alkaline biocontrol organic fertilizer with added Moringa seed fermentation. The Moringa seeds are fermented using enzymatic hydrolysis and microbial agents, which effectively breaks down large molecules into smaller molecules that can be directly absorbed by banana plants, promoting their growth. At the same time, Achromobacterium solani and Acinetobacter griseus secrete a variety of active substances, which have a significant effect on the disease resistance and growth promotion of bananas.

[0031] This invention's alkaline biocontrol organic fertilizer utilizes a large amount of agricultural waste such as tobacco straw, seaweed residue, and shell powder, reducing production costs and meeting the needs of ecological circular agriculture. At the same time, this biocontrol organic fertilizer can gradually neutralize soil acidity, reduce the toxicity caused by acidification in banana plantations, and extend the planting life.

[0032] This invention utilizes an alkaline biocontrol organic fertilizer with multiple substances working synergistically to reduce the use of chemical fungicides, effectively suppressing banana wilt disease, increasing banana yield, and improving economic and social benefits. Attached Figure Description

[0033] Figure 1 The diagram shows the compatibility test results of the two bacteria used in this invention. Note: A is Acinetobacter gastroenterologica and B is Achromobacter solani.

[0034] Figure 2 The graph shows the soil pH values ​​measured after banana harvest for each treatment group. Detailed Implementation

[0035] The technical solution of the present invention will be further described below with reference to specific embodiments, but it is not limited thereto.

[0036] Example 1

[0037] A banana-specific alkaline biocontrol organic fertilizer comprises the following raw materials in parts by weight: 25 parts modified tobacco straw carbonization powder, 20 parts moringa seed fermentation product, 5 parts cactus fermentation product, 10 parts seaweed residue, 8 parts humic acid powder, and 3 parts shell powder.

[0038] The method for preparing the Moringa seed ferment is as follows:

[0039] Step S1: After drying moringa seeds, pulverize them to obtain moringa seed powder. Add a compound hydrolytic enzyme solution containing papain and cellulase, and hydrolyze at 45-55℃ for 4-6 hours. Inactivate at high temperature, cool to room temperature, and set the mixture aside.

[0040] Step S2: Add Achromobacterium sol and Acinetobacter ghurtianum to the mixture and ferment at 30°C for 24-48 hours to obtain Moringa seed ferment.

[0041] In step S1 of the method for preparing moringa seed ferment, the mass-to-volume ratio of moringa seed powder to compound hydrolytic enzyme solution is 1 kg: 2 L.

[0042] The compound hydrolytic enzyme solution contains 15 g / L papain and 10 g / L cellulase.

[0043] In step S2 of the method for preparing Moringa seed ferment, the preservation number of Achromobacterium sol-gel is CGMCC1.4514; the preservation number of Acinetobacter griseus is CGMCC1.15884; the addition amount of Achromobacterium sol-gel is 18 g / L and the addition amount of Acinetobacter griseus is 25 g / L.

[0044] The viable count of the achromobacterium sol-gel is 10 billion / g, and the viable count of Acinetobacter ghurterii is 20 billion / g.

[0045] The method for preparing the modified tobacco straw carbonized powder is as follows:

[0046] Waste tobacco straw was washed, dried, and pulverized through a 100-mesh sieve. It was then placed in a reaction vessel, and nitrogen gas was introduced to purge the air. The mixture was carbonized at 500°C for 2 hours. After carbonization, it was cooled to room temperature. The carbonized powder was then soaked in a 5% calcium hydroxide solution and stirred for 2-3 hours. After filtration, it was dried. The carbonized powder was then mixed with magnesium oxide and calcined at 400°C for 1.5 hours. Finally, it was stirred in a 10% urea-formaldehyde-nitrogen solution at 60°C for 2 hours and then dried to obtain modified tobacco straw carbonized powder.

[0047] In the preparation method of the modified tobacco straw carbonized powder, the solid-liquid ratio of carbonized powder, magnesium oxide, 5% calcium hydroxide solution and 10% urea-formaldehyde nitrogen solution is 100g:15g:500mL:400mL.

[0048] A method for preparing an alkaline biocontrol organic fertilizer specifically for bananas includes the following steps:

[0049] (1) After slicing fresh cactus, dry it at 60℃ with a moisture content of less than 10%, crush it through a 60-mesh sieve to remove fiber clumps, adjust the moisture content to 50-55%, add EM bacteria to ferment for 7 days, spread it out to dry until the moisture content is less than 20%, and obtain cactus fermented product.

[0050] (2) Mix the modified tobacco straw carbonization powder, humic acid powder and shell powder evenly, add moringa seed ferment, cactus ferment and seaweed residue, and stir until there are no lumps to obtain the mixture.

[0051] (3) The mixture is granulated using a disc granulator, 5% water is sprayed in to assist in the molding, and particles with a diameter of 2-4 mm are screened out. The mixture is dried at 50°C until the moisture content is less than 10% to obtain the final product, alkaline biocontrol organic fertilizer.

[0052] Organic fertilizers have a pH value greater than 8.

[0053] Compatibility assay between strains

[0054] After activating the cryopreserved Achromobacterium sol-gel and Acinetobacter graniferum, they were streaked onto LB agar plates and incubated at 30°C for 3-5 days. Single colonies of each strain were then streaked onto separate agar plates to demonstrate whether there was any mutual inhibition between the two strains.

[0055] The growth status of the two bacterial strains is as follows: Figure 1 As shown, A is Acinetobacter ghurterii and B is Achromobacter solani. There is no obvious inhibition zone between the two bacteria, indicating that there is no obvious inhibitory effect between them, and they can be combined.

[0056] Example 2

[0057] A banana-specific alkaline biocontrol organic fertilizer comprises the following raw materials in parts by weight: 28 parts modified tobacco straw carbonization powder, 22 parts moringa seed fermentation product, 8 parts cactus fermentation product, 12 parts seaweed residue, 10 parts humic acid powder, and 4 parts shell powder.

[0058] The method for preparing the Moringa seed ferment is as follows:

[0059] Step S1: After drying moringa seeds, pulverize them to obtain moringa seed powder. Add a compound hydrolytic enzyme solution containing papain and cellulase, and hydrolyze at 45-55℃ for 4-6 hours. Inactivate at high temperature, cool to room temperature, and set the mixture aside.

[0060] Step S2: Add Achromobacterium sol and Acinetobacter ghurtianum to the mixture and ferment at 30°C for 24-48 hours to obtain Moringa seed ferment.

[0061] In step S1 of the method for preparing moringa seed ferment, the mass-to-volume ratio of moringa seed powder to compound hydrolytic enzyme solution is 1 kg: 2 L.

[0062] The compound hydrolytic enzyme solution contains 16 g / L papain and 12 g / L cellulase.

[0063] In step S2 of the method for preparing Moringa seed ferment, the preservation number of Achromobacterium sol-gel is CGMCC1.4514; the preservation number of Acinetobacter Gastroenteritis is CGMCC1.15884; the amount of Achromobacterium sol-gel added is 20 g / L and the amount of Acinetobacter Gastroenteritis added is 27 g / L.

[0064] The viable count of the achromobacterium sol-gel is 10 billion / g, and the viable count of Acinetobacter ghurterii is 20 billion / g.

[0065] The method for preparing the modified tobacco straw carbonized powder is as follows:

[0066] Waste tobacco straw was washed, dried, and pulverized through a 100-mesh sieve. It was then placed in a reaction vessel, and nitrogen gas was introduced to purge the air. The mixture was carbonized at 500°C for 2 hours. After carbonization, it was cooled to room temperature. The carbonized powder was then soaked in a 5% calcium hydroxide solution and stirred for 2-3 hours. After filtration, it was dried. The carbonized powder was then mixed with magnesium oxide and calcined at 400°C for 1.5 hours. Finally, it was stirred in a 10% urea-formaldehyde-nitrogen solution at 60°C for 2 hours and then dried to obtain modified tobacco straw carbonized powder.

[0067] In the preparation method of the modified tobacco straw carbonized powder, the solid-liquid ratio of carbonized powder, magnesium oxide, 5% calcium hydroxide solution and 10% urea-formaldehyde nitrogen solution is 100g:15g:500mL:400mL.

[0068] A method for preparing an alkaline biocontrol organic fertilizer specifically for bananas includes the following steps:

[0069] (1) After slicing fresh cactus, dry it at 60℃ with a moisture content of less than 10%, crush it through a 60-mesh sieve to remove fiber clumps, adjust the moisture content to 50-55%, add EM bacteria to ferment for 7 days, spread it out to dry until the moisture content is less than 20%, and obtain cactus fermented product.

[0070] (2) Mix the modified tobacco straw carbonization powder, humic acid powder and shell powder evenly, add moringa seed ferment, cactus ferment and seaweed residue, and stir until there are no lumps to obtain the mixture.

[0071] (3) The mixture is granulated using a disc granulator, 5% water is sprayed in to assist in the molding, and particles with a diameter of 2-4 mm are screened out. The mixture is dried at 50°C until the moisture content is less than 10% to obtain the final product, bio-control organic fertilizer.

[0072] The pH value of biocontrol organic fertilizer is greater than 8.

[0073] Example 3

[0074] A banana-specific alkaline biocontrol organic fertilizer comprises the following raw materials in parts by weight: 30 parts modified tobacco straw carbonization powder, 25 parts moringa seed fermentation product, 10 parts cactus fermentation product, 14 parts seaweed residue, 12 parts humic acid powder, and 5 parts shell powder.

[0075] The method for preparing the Moringa seed ferment is as follows:

[0076] Step S1: After drying moringa seeds, pulverize them to obtain moringa seed powder. Add a compound hydrolytic enzyme solution containing papain and cellulase, and hydrolyze at 45-55℃ for 4-6 hours. Inactivate at high temperature, cool to room temperature, and set the mixture aside.

[0077] Step S2: Add Achromobacterium sol and Acinetobacter ghurtianum to the mixture and ferment at 30°C for 24-48 hours to obtain Moringa seed ferment.

[0078] In step S1 of the method for preparing moringa seed ferment, the mass-to-volume ratio of moringa seed powder to compound hydrolytic enzyme solution is 1 kg: 2 L.

[0079] The compound hydrolytic enzyme solution contains 18 g / L papain and 14 g / L cellulase.

[0080] In step S2 of the method for preparing Moringa seed ferment, the preservation number of Achromobacterium sol-gel is CGMCC1.4514; the preservation number of Acinetobacter Gastroenteritis is CGMCC1.15884; the amount of Achromobacterium sol-gel added is 22 g / L and the amount of Acinetobacter Gastroenteritis added is 30 g / L.

[0081] The viable count of the achromobacterium sol-gel is 10 billion / g, and the viable count of Acinetobacter ghurterii is 20 billion / g.

[0082] The method for preparing the modified tobacco straw carbonized powder is as follows:

[0083] Waste tobacco straw was washed, dried, and pulverized through a 100-mesh sieve. It was then placed in a reaction vessel, and nitrogen gas was introduced to purge the air. The mixture was carbonized at 500°C for 2 hours. After carbonization, it was cooled to room temperature. The carbonized powder was then soaked in a 5% calcium hydroxide solution and stirred for 2-3 hours. After filtration, it was dried. The carbonized powder was then mixed with magnesium oxide and calcined at 400°C for 1.5 hours. Finally, it was stirred in a 10% urea-formaldehyde-nitrogen solution at 60°C for 2 hours and then dried to obtain modified tobacco straw carbonized powder.

[0084] In the preparation method of the modified tobacco straw carbonized powder, the solid-liquid ratio of carbonized powder, magnesium oxide, 5% calcium hydroxide solution and 10% urea-formaldehyde nitrogen solution is 100g:15g:500mL:400mL.

[0085] A method for preparing an alkaline biocontrol organic fertilizer specifically for bananas includes the following steps:

[0086] (1) After slicing fresh cactus, dry it at 60℃ with a moisture content of less than 10%, crush it through a 60-mesh sieve to remove fiber clumps, adjust the moisture content to 50-55%, add EM bacteria to ferment for 7 days, spread it out to dry until the moisture content is less than 20%, and obtain cactus fermented product.

[0087] (2) Mix the modified tobacco straw carbonization powder, humic acid powder and shell powder evenly, add moringa seed ferment, cactus ferment and seaweed residue, and stir until there are no lumps to obtain the mixture.

[0088] (3) The mixture is granulated using a disc granulator, 5% water is sprayed in to assist in the molding, and particles with a diameter of 2-4 mm are screened out. The mixture is dried at 50°C until the moisture content is less than 10% to obtain the final product, bio-control organic fertilizer.

[0089] The pH value of biocontrol organic fertilizer is greater than 8.

[0090] Comparative Example 1

[0091] Compared with Example 1, this comparative example only added Acinetobacter griseus (43g) during the preparation of Moringa seed fermentation, while the other raw materials and steps were the same as in Example 1.

[0092] Comparative Example 2

[0093] Compared with Example 1, this comparative example only added Achromobacterium sol-gel (43g) during the preparation of Moringa seed fermentation, while the other raw materials and steps were the same as in Example 1.

[0094] Comparative Example 3

[0095] Compared with Example 1, in this comparative example, the Moringa seeds were not fermented with Acinetobacter griseus and Achromobacter sol-gel during the preparation process, while the other raw materials and steps were the same as in Example 1.

[0096] Comparative Example 4

[0097] Compared with Example 1, this comparative example does not add moringa seed fermentation during the preparation process, while the other raw materials and steps are the same as in Example 1.

[0098] Comparative Example 5

[0099] Compared with Example 1, this comparative example is identical to Example 1 except that the tobacco straw carbonized powder is not modified with magnesium oxide and urea-formaldehyde nitrogen liquid.

[0100] Performance testing

[0101] Functional identification of Acinetobacter ghurterenum and Achromobacter sol-gel

[0102] Indoleacetic acid (IAA) production capacity determination: The Salkowski colorimetric method was used to determine the IAA production capacity of the strain. The deeper the red color after the reaction, the stronger the IAA production capacity of the strain. The absorbance was measured at 530 nm, and the IAA production amount was calculated according to the IAA standard curve.

[0103] Potassium solubilization capacity assay: Activated bacterial strains were inoculated into 50 mL of seed culture medium and cultured for 48 h. The cultures were then centrifuged at 6000 rpm for 10 min, and the supernatant was discarded. Bacterial cells without culture medium were collected and resuspended in deionized water to prepare a bacterial suspension (OD200). 600 =0.6). The bacterial suspension was inoculated into potassium-solubilizing liquid medium at an inoculum volume of 5% and cultured for 7 days. An equal volume of inactivated bacterial suspension was used as a control. 10 mL of fermentation broth from the potassium-solubilizing liquid medium was taken, 2 mL of H2O2 was added, and the mixture was digested in a boiling water bath for 1 hour. Then, deionized water was added to make up to 10 mL. The mixture was centrifuged at 10000 r / min for 5 min, and the potassium content of the supernatant was determined by flame spectrophotometry. The results were compared with the blank control to calculate the decomposition rate of potassium feldspar powder by the strain.

[0104] Siderophore production capacity determination: The CAS detection method was used to record the color and size of the orange halo. The diameter (D) of the orange siderophore halo of a single colony and the diameter (d) of the colony were measured using vernier calipers. The siderophore production capacity of the strain was determined by the ratio of D / d.

[0105] Determination of pathogen inhibition ability:

[0106] The antagonistic effect of microbial agents against banana wilt disease was determined using the plate confrontation culture method. A 5 mm diameter mycelium cake was inoculated with the wilt pathogen in the center of a petri dish. Sterilized filter paper discs (5 mm in diameter) were placed approximately 2 cm to the left and right of the pathogen's center. 5 μL of fermentation broth from the two strains prepared in Example 1 of this invention was added to each filter paper disc. A control group was prepared by inoculating only the pathogen mycelium cake without the microbial agent of this invention. Each treatment was repeated three times. The inoculated petri dishes were incubated at 30°C. The colony diameter of the pathogen in each treatment was measured, and the inhibition rate was calculated using the mycelial growth rate method.

[0107] The measurement results are as follows:

[0108] Table 1. Identification of the capabilities of the two strains

[0109] strain IAA mg / L Potassium solubilization rate % Iron production capacity Fusarium wilt inhibition rate % Acinetobacter ghurterenum 42.4 22.53 1.16 52.3 Achromobacterium sol-gel — 1.85 3.71 65.2

[0110] Note: — indicates a negative test reaction.

[0111] Plate contrast experiments revealed that the two strains added in this invention have a significant inhibitory effect on the pathogen of banana wilt disease.

[0112] Planting Trial

[0113] The banana variety tested was the Brazilian banana.

[0114] The experimental field was located in Danzhou City, Hainan Province. The soil was lateritic red soil with a pH of 5.1. Years of banana cultivation there had led to a severe outbreak of banana wilt disease.

[0115] The experiment included nine treatment groups: a conventional fertilization group (CK) and two treatment groups treated with the biocontrol organic fertilizers T1-T8 prepared in Examples 1-3 and Comparative Examples 1-5 of this invention. The conventional fertilization group received 600 kg / hm² of pure nitrogen. 2 P2O5 300kg / hm 2 K2O 900kg / hm 2 The fertilizer was applied in 10 applications; for treatment groups T1-T8, the fertilizer was applied as a single basal fertilizer at a rate of 1 t / hm². 2 Each treatment group was replicated three times. The experimental plots were arranged in a randomized block design with a row spacing of 2.3m and a plant spacing of 2m, with 20 banana plants per plot. Routine management practices were consistent across all treatments.

[0116] Data statistics: Indicators such as yield and control efficacy were statistically analyzed. Disease incidence was investigated, and disease severity was determined based on the percentage of browned area in the longitudinal section of banana bulbs: Level 0: no browning on bulbs; Level 1: browned area ≤ 25% on bulbs; Level 3: 25% < browned area ≤ 50% on bulbs; Level 5: 50% < browned area ≤ 75% on bulbs; Level 7: browned area > 75% on bulbs. Disease index and control efficacy were calculated for each treatment. Disease index = ∑(number of diseased plants at each level × representative value of that level) / (total number of plants × highest representative value) × 100; Control efficacy = (control disease index – treatment disease index) / control disease index × 100%. After banana harvest, topsoil samples were collected from each experimental plot for pH measurement. Statistical results are shown below. Figure 2 .

[0117] Table 2 Planting Effects

[0118] Disease index Prevention and control efficacy % Yield t / mu Production increase rate % CK 20.5 — 2.93 — Example 1 3.9 80.98 4.07 38.91 Example 2 5.7 72.19 4.01 36.86 Example 3 6.1 70.24 3.98 35.87 Comparative Example 1 10.8 47.32 3.62 23.55 Comparative Example 2 8.5 58.54 3.74 27.65 Comparative Example 3 17.3 15.61 3.25 10.92 Comparative Example 4 18.2 11.22 3.19 8.87 Comparative Example 5 7.4 63.9 3.82 30.38

[0119] As shown in Table 2, the biocontrol organic fertilizer of this invention can effectively control banana wilt disease and increase banana yield. However, when the composition of the organic fertilizer is changed in comparison ratios 1-5, the synergistic effect of the various substances is broken, the banana's disease resistance is significantly reduced, and thus the yield is reduced.

[0120] 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 special alkaline bio-organic fertilizer for banana, characterized in that, Prepared with the following raw materials by weight: modified tobacco straw carbonized powder 25-30 parts, moringa seed ferment 20-25 parts, cactus ferment 5-10 parts, seaweed residue 10-14 parts, humic acid powder 8-12 parts, shell powder 3-5 parts; The preparation method of the moringa seed ferment is: Step S1: After drying, the moringa seed is crushed to obtain moringa seed powder, and a complex hydrolytic enzyme solution containing papain and cellulase is added, and enzymolysis is carried out at 45-55℃ for 4-6h, high-temperature inactivation, cooling to room temperature, and the mixture is prepared; Step S2: Add soli acus and acommodans gantensis to the mixture, and ferment at 30℃ for 24-48h to obtain the moringa seed ferment; In step S2, the preservation number of soli acus is CGMCC1.4514, and the preservation number of acommodans gantensis is CGMCC1.15884; the addition amount of soli acus is 18-22g / L, and the addition amount of acommodans gantensis is 25-30g / L; The preparation method of the modified tobacco straw carbonized powder is: The waste tobacco straw is washed, dried, crushed to pass through a 100 mesh sieve, put into a reaction kettle, nitrogen is introduced to exhaust air, carbonized at 500℃ for 2h, after carbonization, cool to room temperature, soak the carbonized powder in 5% calcium hydroxide solution, stir for 2-3h, filter and dry; then mix the carbonized powder with magnesium oxide, calcine at 400℃ for 1.5h, finally stir in 10% urea-formaldehyde nitrogen solution at 60℃ for 2h and dry to obtain the modified tobacco straw carbonized powder.

2. The banana-specific alkaline bio-organic fertilizer according to claim 1, characterized in that, The mass-volume ratio of the moringa seed powder and the complex hydrolytic enzyme solution in step S1 of the preparation method of the moringa seed ferment is 1kg:2L.

3. The banana-specific alkaline bio-organic fertilizer according to claim 1, characterized in that, The complex hydrolytic enzyme solution contains papain 15-18g / L and cellulase 10-14g / L.

4. The banana-specific alkaline bio-organic fertilizer according to claim 1, characterized in that, The viable bacterial count of soli acus is 10 billion / g, and the viable bacterial count of acommodans gantensis is 200 billion / g.

5. The banana-specific alkaline bio-organic fertilizer according to claim 1, characterized in that, In the preparation method of the modified tobacco straw carbonized powder, the solid-liquid ratio of the carbonized powder, magnesium oxide, 5% calcium hydroxide solution and 10% urea-formaldehyde nitrogen solution is 100g:15g:500mL:400mL.

6. A method for preparing the banana-specific alkaline bio-organic fertilizer according to any one of claims 1-5, characterized by, Prepared by the following steps: (1) The fresh cactus is cut into slices, dried at 60℃ to less than 10% moisture, crushed to pass through a 60 mesh sieve, the fiber lumps are removed, the moisture content is adjusted to 50-55%, and the EM microbial agent is added for composting fermentation for 7 days, after fermentation, spread out and air dry to less than 20% moisture to obtain the cactus ferment; (2) Mix the modified tobacco straw carbonized powder, humic acid powder and shell powder evenly, add the moringa seed ferment, cactus ferment and seaweed residue, and stir until there are no lumps to obtain a mixture; (3) The mixture is granulated using a disc granulator, sprayed with 5% water for auxiliary molding, screened out granules with a particle size of 2-4mm, dried at 50℃ to less than 10% moisture to obtain the final product, alkaline biocontrol organic fertilizer.

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