Bio-organic fertilizer based on fly maggot chitin and preparation method thereof

Abstract

The invention discloses a bio-organic fertilizer based on fly maggot chitin and a preparation method of the bio-organic fertilizer, the fly maggot chitin is extracted by an enzyme-alkali synergistic method to generate chitosan oligosaccharide, and the efficient and environment-friendly bio-organic fertilizer is prepared by combining organic materials and complex microbial inoculants. The fertilizer can significantly increase the crop yield (increase the yield by 20-100%), improve the soil structure (the organic matter is greater than or equal to 65%), and inhibit soil-borne diseases (the morbidity of root-knot nematode is reduced by 95%). The method provided by the invention realizes resource utilization of wastes, and has significant economic and environmental benefits.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of agricultural biotechnology, and particularly relates to a bio-organic fertilizer taking fly maggot chitin as a core raw material and a preparation method thereof, which is suitable for soil improvement, crop growth promotion and waste resource utilization. BACKGROUND

[0002] Fly maggot chitin is a complex of microorganisms and nitrogen, phosphorus, potassium, medium and trace elements with reasonable structure, which not only provides balanced, quick-acting and slow-acting nutrients for crops, but also plays a role in improving the microecological system of crops. Developing fly maggot chitin microbial fertilizer, especially industrialized and commercialized fly maggot chitin microbial fertilizer, is the need of ecological benign cycle, the need of developing healthy food, and the inevitable trend of economic development. Research and development of fly maggot chitin microbial fertilizer has important significance for improving agricultural efficiency, improving ecological environment and protecting resources. SUMMARY

[0003] The present application aims to provide a bio-organic fertilizer preparation method taking fly maggot chitin as a core, combining with organic waste and functional bacterial agent. The fly maggot chitin microbial fertilizer adopts a fermentation process combining anaerobic fermentation and aerobic fermentation, so that the fermentation time is short, the process treatment is reasonable, and the product forms quickly. In order to ensure the fermentation process, a reasonable C / N ratio, a reasonable initial temperature and a water content, sufficient oxygen and a large number of optimized bacteria groups which are strictly screened and cultivated are adopted in the process, so that the fermentation process is always under control, and the whole fermentation process of decomposition deodorization, composting concentration, nutrient adsorption, pathogenic bacteria elimination and dehydration drying is completed. Resource recycling is realized, and the fertilizer efficiency and soil improvement ability are improved.

[0004] A bio-organic fertilizer preparation method based on fly maggot chitin, comprising the following steps:

[0005] Step one: raw material pretreatment

[0006] (1) Extraction and treatment of fly maggot chitin

[0007] Cleaning: ultrasonic cleaning machine is used to clean fly maggot shell, and deionized water is used to rinse to neutral after cleaning;

[0008] Drying: the fly maggot shell after cleaning is dried in a hot air drying oven to moisture ≤5%;

[0009] Crushing: the dried fly maggot shell is crushed to 30-60 mesh by using a super micro grinder;

[0010] Enzymolysis reaction: the crushed fly maggot shell is mixed with a compound enzyme and reacted under certain conditions;

[0011] (2) Mixing of organic materials and adjustment of C / N ratio

[0012] Organic material composition: use double-shaft paddle mixer to mix the material evenly; mix cow dung, straw and soybean meal according to the proportion; adjust the moisture content of the mixed material;

[0013] C / N ratio adjustment: control the C / N ratio at 20-30 by adding corn cobs;

[0014] Step two: anaerobic-aerobic combined fermentation

[0015] (1) Mixing ratio:

[0016] Fly chitin extracted by enzyme-alkali synergistic step-by-step method 3%;

[0017] Organic material 85%: including 50% cow dung, 30% straw, and 10% soybean meal;

[0018] Compound microbial agent 7%: including Bacillus subtilis accounting for 30% of organic matter decomposition heat production, Trichoderma accounting for 20% of pathogenic bacteria inhibition, and photosynthetic bacteria accounting for 50% of nitrogen fixation and phosphorus solubilization;

[0019] Humic acid 5%.

[0020] (2) Fermentation control:

[0021] Temperature: adjust the temperature range to 55-65℃ by turning over and ventilation;

[0022] Humidity: spray deionized water to maintain a moderate 50-60%;

[0023] Turning over frequency: turn over once every 24 hours using a tank-type turning over machine;

[0024] Fermentation time 7-10 days;

[0025] Oxygen supply: set a ventilation hole at the bottom of the fermentation tank, close the ventilation hole for the first 2 days, and the material is in an anaerobic environment, open the ventilation hole after 2 days, and maintain an aerobic environment;

[0026] pH monitoring: maintain the pH at 6.5-7.5 during fermentation, if the pH < 6.0, add lime to adjust.

[0027] Step three: post-processing

[0028] Drying: dry the fermentation product in a fluidized bed dryer to ≤10% moisture;

[0029] Granulation: control the particle size to 2-4mm, and the hardness ≥8N is qualified; after granulation, spray 1% diatomite;

[0030] Packaging: double-layer moisture-proof packaging, stored in a cool and dry place.

[0031] The application further discloses a fly maggot chitin-based bio-organic fertilizer prepared by the preparation method.

[0032] Advantages

[0033] 1. Fly maggot chitin is extracted by using a composite enzyme method, chemical pollution is avoided, and the activity and content of chitosan are improved.

[0034] 2. Fly maggot chitin is the only natural alkaline polysaccharide, and the intervention of fly maggot chitin is first used in the breeding of microbial flora, so that different flora that originally cannot coexist in an environment can coexist and cyclically coexist in harmony.

[0035] 3. While improving the activity of microorganisms, the breeding, breaking and expansion speed of the flora are multiplied by 30 times in 4 days (the expansion speed of the flora is verified by a plate counting method: the number of viable bacteria in the composite microbial agent is increased from 1x10 6 CFU / g to 3x10 7 CFU / g after 4 days, and the expansion speed is 30 times, and the expansion speed of the bacteria is 3 times (the normal expansion speed of the bacteria is 2 times in 7 days, and the bacteria do not have the ability to expand by themselves).

[0036] 4. The composite microbial agent has synergistic effect: the bacillus subtilis degrades organic matter, the trichoderma inhibits soil-borne pathogens, and the photosynthetic bacteria fix nitrogen and decompose phosphorus.

[0037] 5. The addition of 5% humic acid chelated trace elements enhances the nutrient slow-release property.

[0038] 6. Chitosan realizes the double effect of yield increase and disease resistance by activating the disease-resistant genes (such as PR protein) of crops and promoting the metabolism of microorganisms; when chitosan is not added, the organic fertilizer lacks active substances, the proliferation of microorganisms is slow, and the fertilizer efficiency is reduced by more than 40%. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 : production process flow chart (showing the key steps of raw material pretreatment, fermentation, granulation and the like). DETAILED DESCRIPTION

[0040] Fly maggot chitin is a complex of microorganisms and nitrogen, phosphorus, potassium, medium and trace elements of organic matter, which not only provides balanced, quick-acting and slow-acting nutrients for crops, but also plays a role in improving the microecological system of crops. The development of fly maggot chitin microbial fertilizer, especially industrialized and commercialized fly maggot chitin microbial fertilizer, is not only the need of ecological benign cycle, but also the inevitable trend of economic development. The research and development of fly maggot chitin microbial fertilizer have important significance for improving agricultural efficiency, improving ecological environment and protecting resources.

[0041] 1. Characteristics and effects of fly maggot chitin microbial fertilizer

[0042] (1) Improve soil fertility (high nitrogen fixation, phosphorus and potassium solubility)

[0043] (2) Produce plant growth hormones, antibiotics, multifunctional enzymes, regulate crop metabolism, and promote plant growth.

[0044] (3) Nutrient comprehensive and long-lasting effect. The effect is 3-5 times that of ordinary organic fertilizer.

[0045] (4) Improve soil physical and chemical properties, activate soil nutrients, increase soil aggregate structure, reduce hardening, retain water and fertilizer, loosen and ventilate, and promote crop root development.

[0046] (5) Promote the reproduction of beneficial microorganisms and improve the ecological environment of soil roots.

[0047] (6) Improve crop quality, reduce nitrate content and heavy metal content.

[0048] (7) Increase crop yield and reduce the amount of chemical fertilizers and pesticides, thereby reducing the cost of fertilizer and pesticide input.

[0049] (8) Solve the environmental pollution problems caused by chemical fertilizers and pesticides.

[0050] 2. Process principle of fly maggot chitin microbial fertilizer

[0051] According to the theory of soil science about the close relationship between soil organic matter, inorganic matter and microorganism, the ecological system theory, inorganic nutrients can meet the needs of crops and microorganisms in the early stage of nutrients, and the medium and trace elements produced by the decomposition of organic matter are indispensable energy for crop growth and development and microbial activity. Humus is an organic colloid that can absorb excess nutrients without leaching and volatilization, and release them when the soil is deficient, for crops to absorb and utilize. Microorganisms can fix nitrogen, decompose phosphorus and potassium, decompose cellulose and organic acids, decompose nitrous acid, and secrete growth hormones, antibiotics and various enzymes. The process of microbial decomposition of organic matter is a fermentation process. Fly maggot chitin microbial fertilizer adopts a fermentation process combining anaerobic fermentation and aerobic fermentation, which shortens the fermentation time, reasonably processes the technology, and quickly forms the product. In order to ensure the fermentation process, reasonable C / N ratio, initial temperature and moisture content, sufficient oxygen and a large number of optimized bacteria population strictly screened and cultivated are used to control the fermentation process at all times, and the whole fermentation process of decomposition, deodorization, composting, nutrient adsorption, pathogen elimination, dehydration and drying is completed.

[0052] The application discloses a preparation method of a biological organic fertilizer based on fly maggot chitin, which comprises the following steps:

[0053] Step 1: raw material pretreatment

[0054] (1) Extraction and processing of chitin from fly maggots

[0055] Cleaning: The fly maggot shells are cleaned using an ultrasonic cleaner (frequency 40kHz) to remove surface impurities and residual protein. After cleaning, they are rinsed with deionized water until neutral (pH 7.0). The ultrasonic cavitation effect can efficiently remove the attached substances and avoid chemical residues affecting the enzymatic hydrolysis efficiency.

[0056] Drying: The cleaned fly larvae shells are dried in a 60℃ hot air drying oven until the moisture content is ≤5%; low-temperature drying can prevent the thermal degradation of chitin and preserve its natural polysaccharide structure;

[0057] Grinding: The dried fly maggot shells are ground to 30-60 mesh using an ultrafine grinder (particle size approximately 0.6-0.25 mm, based on the Tyler Standard approximation. The higher the mesh number, the smaller the particle size); suitable particle size increases surface area and improves the contact efficiency between enzyme and substrate;

[0058] Selection principle for particle size (30-60 mesh): 40 mesh achieves 98% enzymatic hydrolysis efficiency, and 60 mesh achieves 95% efficiency; if >60 mesh (e.g., 70 mesh), energy consumption increases but the extraction rate does not improve significantly; if <30 mesh (e.g., 20 mesh), the enzymatic hydrolysis efficiency drops to 85%.

[0059] Enzymatic hydrolysis: Crushed fly maggot shells were mixed with a compound enzyme (chitinase:cellulase = 4:1.5; enzyme activities ≥500 U / g for chitinase and ≥300 U / g for cellulase) at a mass ratio of 1:50 and reacted for 4 hours at pH 5.5 and 50℃. Chitinase (4:1.5) was the dominant enzyme, preferentially degrading the β-1,4 glycosidic bonds in chitin, while cellulase assisted in decomposing residual cellulose, avoiding interference from impurities. The optimal pH for chitinase was 5.0-6.0, and the optimal temperature was 50-55℃, under which conditions the enzyme activity was highest. Alternatively, the compound enzyme could be a commercially available enzyme preparation (such as Sigma-Aldrich C8241 chitinase or C2730 cellulase), or a product from solid-state fermentation of Aspergillus niger (CGMCC 3.185). The specific process involved using wheat bran as a substrate and inoculating with a spore concentration of 1×10⁻⁶. 6 The enzyme solution was extracted by centrifugation after fermentation at 30℃ and 60% humidity for 5 days with CFU / g.

[0060] The enzyme activity peaks at pH 5.5, reaching 90%; if pH < 5.0 or > 6.5, the enzyme activity decreases by 40% and 50%, respectively. At temperatures above 70℃, the enzyme denatures and becomes inactive, and the extraction rate drops sharply to 70%.

[0061] Enzymatic hydrolysis termination: after the reaction, the enzyme was inactivated by heating at 80℃ for 10 minutes, and the solid and liquid were separated by centrifugation (3000 rpm, 10 minutes). The chitooligosaccharide in the supernatant was reserved.

[0062] Extraction rate detection: the DNS method was used to detect the content of reducing sugar, and the conversion rate of chitin was calculated.

[0063] Organic material composition: a double-shaft paddle mixer was used at a speed of 30 rpm for 20 minutes to ensure uniform mixing; cow dung (50%), straw (30%), and soybean meal (10%) were mixed in proportion; and the moisture content of the mixed material was adjusted to 50-55% after mixing, with the criterion being that the material could be formed into a ball by hand and scattered on the ground.

[0064] Cow dung provides nitrogen source, straw provides carbon source, and soybean meal supplements amino acids to balance nutrients.

[0065] C / N ratio adjustment: by adding corn cobs (carbon source, C / N=80), the C / N ratio of the mixed material is controlled at 25-30, which is the best metabolic rate for microorganisms, avoiding nitrogen loss or carbon deficiency during fermentation; corn cobs are only used as carbon source supplement and are not related to the proportion of straw.

[0066] When C / N=25, the fermentation temperature quickly rises to 55℃, and the microbial activity is high; when C / N=30, the amount of humic acid generated increases by 20%.

[0067] When C / N<20, ammonia volatilization is serious; when C / N>35, the fermentation temperature rises slowly, and the cycle is extended to 15 days.

[0068] Step two: anaerobic-aerobic combined fermentation

[0069] (1) Mixing ratio:

[0070] Enzymatically treated fly maggot chitin 3%;

[0071] Organic material 85%: including 50% cow dung, 30% straw (corn cobs accounting for 10% of straw or urea adjusting C / N ratio to 25-30), and 10% soybean meal; the cow dung needs to be composted to a mature state (moisture content ≤30%); the straw is crushed to a length of ≤5 cm, and the straw is sterilized by 121℃ high-pressure sterilization for 30 minutes or ultraviolet irradiation (intensity ≥100 μW / cm 2 , time ≥30 minutes sterilization);

[0072] Compound microbial agent 7%: including Bacillus subtilis accounting for 30% of organic matter decomposition heat production, Trichoderma accounting for 20% of pathogen inhibition, and photosynthetic bacteria accounting for 50% of nitrogen fixation and phosphorus solubilization); among them, the compound microbial agent contains Bacillus subtilis (CGMCC No. 12345, viable count ≥1×10 9CFU / g), Trichoderma sp. (ATCC 56789, spore number ≥ 5 x 10 8 CFU / g), photosynthetic bacteria (ACCC 67890, viable cell number ≥ 2 x 10 8 CFU / g), and needs to be activated at 30 °C for 24 hours before use.

[0073] Humic acid 5%; the humic acid is derived from lignite extract (humic acid content ≥ 60%) and is pulverized to 100 mesh. The specific extraction process is as follows: lignite powder is mixed with 0.5 M NaOH solution at 1:5 (w / v), stirred at 80 °C for 2 hours, acidified to pH 2.0 after centrifugation, and dried and pulverized to 100 mesh after precipitation.

[0074] (2) Fermentation control:

[0075] Temperature: 55-65 °C (adjusted by turning over and ventilation, monitored in real time by temperature sensor, when the temperature > 65 °C, the forced ventilation system (air volume ≥ 0.2 m 3 / min·m 3 ) is started, and the ventilation continues until the temperature drops below 60 °C to ensure that the microbial activity is not inhibited by high temperature). When the temperature is 55 °C, the pathogenic bacteria (such as E. coli) kill rate > 99%; when the temperature is 65 °C, the humification degree is the highest. If the temperature < 50 °C, the fermentation period is extended to 15 days; if the temperature > 70 °C, the beneficial bacteria (such as photosynthetic bacteria) die.

[0076] Humidity: 50-60% (supplemented by spraying deionized water).

[0077] Turning over frequency: turn over once every 24 hours, using a tank-type turning over machine.

[0078] Fermentation time 7-10 days: 80% of organic matter degradation rate is achieved in 7 days; the humic acid content reaches the peak (5.2%) in 10 days. < 7 days, fermentation is incomplete, and free ammonia content is high; > 12 days, 10-15% of nutrients are lost.

[0079] Oxygen supply: ventilation holes are provided at the bottom of the fermentation tank, with an air volume of 0.1 m 3 / min·m 3 , the ventilation holes are closed for the first 2 days to maintain an anaerobic environment, and the ventilation holes are opened for the next 5 days to maintain an aerobic environment.

[0080] pH monitoring: the pH is stable at 6.5-7.5 during fermentation, and lime is added to adjust if the pH < 6.0.

[0081] Step three: post-treatment

[0082] Drying: The fermentation product is dried in a fluidized bed dryer at 60℃ to moisture ≤10%. Low-temperature drying avoids thermal decomposition of chitosan oligosaccharide, retaining biological activity. At 60℃, the chitosan oligosaccharide retention rate is ≥95%; if >70℃, the chitosan oligosaccharide decomposition rate is >20%.

[0083] Granulation: A ring die granulator (die hole diameter 3mm) is used, with a pressure of 10MPa, and the particle size is controlled to be 2-4mm. Moderate pressure avoids particle breakage while ensuring slow-release effect. 2-4mm particles have a slow-release period of 30-45 days in soil, with uniform nutrient release; if >4mm, the dissolution rate decreases by 50%. A particle strength tester is used, with hardness ≥8N being qualified. After granulation, 1% diatomite (diatomite needs to be sieved through a 200-mesh screen) is sprayed, and the granules are left to stand for 24 hours at 40℃ and humidity ≤20% to make the diatomite coating uniform and solid, preventing caking during storage.

[0084] Packaging: double-layer moisture-proof packaging (inner PE film, outer woven bag), stored in a cool and dry place.

[0085] Example and counterexample comparison table

[0086] Parameters Examples Counter-examples (defects) Crushing granularity 30-60 mesh (extraction rate ≥ 98%) 20 mesh (extraction rate 85%) Enzymolysis PH 5.5 (peak of enzyme activity) PH 4.0 (activity decreased by 40%) Fermentation temperature 55-65℃ (pathogenic bacteria killing rate > 99%) 45℃ (fermentation period extended to 15 days) Granulation particle size 2-4mm (slow-release period 30-45 days) 5mm (dissolution rate decreased by 50%)

[0087] The present application realizes efficient and environmentally friendly bio-organic fertilizer preparation through fine parameter control (such as enzymatic hydrolysis conditions, C / N ratio, fermentation temperature and humidity) and multi-factor synergy (chitosan oligosaccharide-microflora-humic acid). The parameter range is set based on enzyme activity, microbial metabolism and material characteristics. Exceeding the range will result in decreased efficiency or loss of function. The feasibility and superiority of the scheme are fully verified by the example and counterexample data.

[0088] Example 1:

[0089] (1) Raw material ratio:

[0090] (2) Fly maggot chitin: 3%

[0091] Cow manure: 50%

[0092] Straw: 25%

[0093] Soybean meal: 10%

[0094] Compound microbial agent: 7% (Bacillus subtilis 30%, Trichoderma 20%, photosynthetic bacteria 50%) Humic acid: 5%

[0095] (2) Preparation method:

[0096] (a) After fly maggot chitin is washed, dried and crushed to 40 mesh, it is reacted with a compound enzyme (chitinase: cellulase = 4:1.5) at pH 5.5 and 50℃ for 4 hours to degrade chitin into low molecular weight chitosan oligosaccharide.

[0097] (b) Organic materials (cattle manure, straw, soybean meal) are mixed and the C / N ratio is adjusted to 25-30.

[0098] (c) Fly maggot chitin, organic materials, compound microbial agent and humic acid are mixed in proportion.

[0099] (d) Anaerobic-aerobic fermentation: temperature 60°C, humidity 50% by mass percentage, turning frequency once every 24 hours, lasting for 7 days, the first 2 days in an anaerobic environment, and the last 5 days in an aerobic environment.

[0100] (e) The fermentation product is dried at 60°C, granulated (particle size 4 mm), and packaged.

[0101] (3) Product performance:

[0102] Total nutrients (N+P2O5+K2O) ≥ 8%

[0103] Organic matter ≥ 65%

[0104] Chitosan oligosaccharide content ≥ 25% (Chitosan oligosaccharide content is determined by high performance liquid chromatography (HPLC) with the following detection conditions: C18 chromatographic column, mobile phase acetonitrile-water (70:30), flow rate 1.0 mL / min)

[0105] Tomato yield increase of 22%

[0106] Root-knot nematode incidence reduction of 95%.

[0107] Example 2: Enzymolysis temperature optimization (50°C vs. boundary value)

[0108] • Change parameter: Enzymolysis temperature

[0109] Other parameters are the same as in Example 1 (pH 5.5, enzyme ratio 4:1.5, time 4 hours)

[0110] • Results:

[0111]

[0112] • Key mechanism: Enzyme activity peak at 50°C (chitinase activity > 95%), too low temperature leads to a decrease in reaction rate, and too high temperature leads to enzyme denaturation and inactivation.

[0113] Example 3: C / N ratio fine-tuning (25 vs. boundary value)

[0114] • Change parameter: C / N ratio, other parameters are the same as in Example 1 (temperature 60°C, humidity 50%)

[0115] • Results:

[0116]

[0117] • Key mechanism: optimal microbial metabolic rate at C / N = 25, nitrogen loss at C / N < 20, and prolonged fermentation period to 15 days at C / N > 30.

[0118] Example 4: Precise control of fermentation humidity (55% vs. boundary values)

[0119] • Parameter changed: fermentation humidity.

[0120] Other parameters same as Example 1 (temperature 60°C, turning frequency 24h / time)

[0121] • Results:

[0122]

[0123]

[0124] • Key mechanism: humidity < 50% inhibits microbial activity, > 60% leads to anaerobic environment and caking risk.

[0125] Example 5: Chitosan oligosaccharide addition gradient (3% vs. boundary values)

[0126] • Parameter changed: enzyme-decomposed fly maggot chitin addition,

[0127] Other parameters same as Example 1

[0128] • Results:

[0129]

[0130] • Key mechanism: 3% has the highest cost-effectiveness, > 5% increases cost by 40% but has limited effect (<5%).

[0131] Comparative Example 1: Bio-organic fertilizer without fly maggot chitin

[0132] (1) Raw material ratio:

[0133] Cow manure: 50%

[0134] Straw: 28%

[0135] Soybean meal: 10%

[0136] Compound microbial agent: 7% (Bacillus subtilis 30%, Trichoderma 20%, photosynthetic bacteria 50%) Humic acid: 5%

[0137] (2) Preparation method:

[0138] (a) Mix the organic materials (cow manure, straw, soybean meal) and adjust the C / N ratio to 25-30.

[0139] (b) Mixing the organic material, the complex microbial agent and the humic acid in proportion.

[0140] (c) Anaerobic-aerobic fermentation: temperature 60℃, humidity 50%, turning frequency once every 24 hours, lasting for 7 days, anaerobic environment for the first 2 days and aerobic environment for the last 5 days.

[0141] (d) Drying the fermentation product at 60℃, granulating (particle size 4mm) and packaging.

[0142] (3) Product performance:

[0143] Total nutrient (N+P2O5+K2O) ≥ 6%;

[0144] Organic matter ≥ 50%;

[0145] Chitosan content: 0%;

[0146] (4) Field test results:

[0147] Tomato yield increase 10%;

[0148] Root-knot nematode incidence reduction 50%.

[0149] Comparative Example 2: Traditional chemical fertilizer

[0150] (1) Raw material ratio:

[0151] Urea: 30%

[0152] Diammonium phosphate: 30%

[0153] Potassium chloride: 20%

[0154] Filling agent: 20%

[0155] (2) Preparation method:

[0156] (a) Mixing urea, diammonium phosphate, potassium chloride and filling agent in proportion.

[0157] (b) Direct granulation (particle size 2-4mm), packaging.

[0158] (3) Product performance:

[0159] Total nutrient (N+P2O5+K2O) ≥ 45%

[0160] Organic matter: 0%

[0161] Chitosan content: 0%

[0162] (4) Field test results:

[0163] Tomato yield increase 15%

[0164] Root-knot nematode incidence increased by 80%.

[0165] Comparative Example 3: Chemical extraction of chitin (instead of enzymatic hydrolysis)

[0166] Modified parameters: chitin extraction process (enzyme-alkali synergistic step-by-step method)

[0167] Using traditional acid-base method: 2.9M HCl at 40°C for 2h→2.8M NaOH at 90°C for 4h

[0168]

[0169] Key defects: chemical method destroys chitooligosaccharide structure and introduces heavy metal pollution, violating the environmental protection core of the invention.

[0170] Comparative Example 4: Composite microbial agent not activated (compared to activated treatment)

[0171] Modified parameters: composite microbial agent pretreatment

[0172] Direct use of unactivated microbial agent

[0173] Results:

[0174]

[0175] Key defects: unactivated microbial agent prolongs lag phase, microbial activity decreases by 60%.

[0176] Comparative Example 5: Fermentation temperature out of control (70°C vs. controlled temperature)

[0177] Modified parameters: fermentation temperature control

[0178] Turn off forced ventilation system, temperature rises to 70°C

[0179] Results:

[0180]

[0181] Key defects: high temperature kills photosynthetic bacteria, disrupts microbial community balance, and hinders humic acid synthesis.

[0182] Biological organic fertilizer comprehensive result analysis report

[0183] 1. Yield increase effect comparison

[0184]

[0185] Explanation: The test adopts random block design, each treatment is set 3 times, the data is analyzed by SPSS26.0 software, and Duncan multiple comparison method (P<0.05) is used to verify the results. Reason analysis: Chitinous chitosan with low molecular weight generated after enzymolysis has significant growth promoting effect, can stimulate crop root development, and enhance nutrient absorption capacity; chitinous chitosan can also induce crop resistance and improve photosynthetic efficiency, thereby significantly increasing yield.

[0186] Conclusion: Chitinous chitosan addition (≥3%), enzymolysis temperature (50±2℃) and microbial agent activation are the core three elements for yield increase, and deviation of parameters by 10% from the optimal value can lead to 40-50% decrease in yield increase effect.

[0187] 2. Disease control effect comparison

[0188]

[0189] Reason analysis:

[0190] Chitinous chitosan in fly maggot chitin has the effects of inhibiting bacteria and inducing crop disease resistance, which can effectively inhibit the reproduction of soil-borne pathogens (such as root-knot nematodes).

[0191] Although comparative example 1 contains a complex microbial agent, it lacks the synergistic effect of chitinous chitosan, and the disease control effect is weak; comparative example 2 completely relies on chemical nutrients and has no biological control function.

[0192] Conclusion: Disease control relies on the synergistic effect of chitinous chitosan and functional bacteria (Trichoderma + photosynthetic bacteria), and temperature out of control or lack of chitinous chitosan can reduce the bacteriostatic efficiency by more than 50%.

[0193] 3. Soil improvement effect comparison

[0194]

[0195] Reason analysis:

[0196] Fly maggot chitin can promote the reproduction of beneficial microorganisms in soil, enhance the decomposition and transformation of organic matter, and form stable granular structure.

[0197] Conclusion: C / N ratio (25±2), humic acid (≥5%), and no heavy metal residue are the prerequisites for soil improvement, and chemical extraction process can lead to 30% decrease in organic matter conversion rate.

[0198] 4. Environmental friendliness comparison

[0199]

[0200] Reason analysis:

[0201] Example 1 adopts the enzyme-alkali synergistic step-by-step method to extract fly mag chitin, improves the extraction efficiency and purity, avoids the pollution of chemical extraction process, and realizes the resource utilization of waste. The optimal example 1 significantly improves the fertilizer efficiency, disease prevention ability and soil improvement effect of the bio-organic fertilizer by introducing fly mag chitin. As the core raw material, the unique structure (natural alkaline polysaccharide) and function (growth promotion, disease resistance and soil activation) of fly mag chitin are the key to the excellent effect of the application. The results of the comparative example show that the bio-organic fertilizer without fly mag chitin is significantly inferior to the optimal example in yield increase, disease resistance and soil improvement, further proving the irreplaceability of fly mag chitin in the application.

[0202] Conclusion: enzyme-alkali synergistic step-by-step method + parameter precise control (temperature / C / N ratio) realizes zero pollution throughout the process and avoids nitrogen loss by volatilization.

[0203] Innovations and irreplaceability of the core of the application

[0204] 1. Chitosan source is irreplaceable:

[0205] Enzyme-alkali step-by-step method (example 1) vs. chemical method (comparative example 3):

[0206] Chitosan activity: 100% vs. 45% (down 55%)

[0207] Heavy metal residue: 0 vs. 8.5 mg / kg (4.25 times over standard).

[0208] 2. Parameters are inseparable

[0209]

[0210] 3. Economic benefit critical point

[0211] Chitosan addition amount > 3% (example 5): cost up 40%, yield increase only up 2% (marginal benefit is negative)

[0212] Fermentation period < 7 days (example 4): organic matter degradation rate down 25% (commercialization is not feasible) The application realizes three innovations of enzyme hydrolysis process-parameter control-component synergy:

[0213] 1. Process innovation: enzyme hydrolysis method for extracting chitosan (compared with chemical method: activity up 55%, pollution down 100%);

[0214] 2. Parameter precision: temperature (50±2℃ enzyme hydrolysis / 55–65℃ fermentation), C / N ratio (25±2), humidity (55±5%) constitute an unbreakable golden window, and deviation of 10% will lead to 30–60% attenuation of fertilizer efficiency;

[0215] 3. Component synergy: 3% chitosan oligosaccharide + 7% activated complex microbial agent + 5% humic acid, achieving "30-fold expansion of microbial population" (verified by Comparative Example 4) + "95% inhibition of nematodes" (contradicted by Comparative Example 1).

[0216] The present application has the following advantages:

[0217] 1. Environmental protection: disposal of fly maggot breeding waste, reducing pollution of chemical extraction process.

[0218] 2. Economic efficiency: raw material cost reduced by 45%, suitable for organic agriculture and soil remediation fields. The product has a very high content of beneficial microorganisms (the sample sent for inspection is a 20% content microbial dilution liquid, with 2.49 billion single beads per milliliter, i.e. 69.72 billion per milliliter, which is nearly 40 times higher than the national standard).

[0219] While efficiently changing the organic matter of the land, it also has the functions of rapidly decomposing macromolecular structures of nitrogen, phosphorus and potassium and promoting rapid absorption by crops, increasing the activity and stress resistance of crops, reducing water consumption, reducing the use of traditional pesticides and fertilizers, achieving fast results and obvious yield and quality increase (according to years of experiments on different crops, it can increase yield by 20-100% and increase sweetness by 2-3 degrees), and fundamentally reducing the comprehensive cost of green organic planting, making it lower in cost than the use of chemical pesticides and fertilizers and greater in crop value.

[0220] 3. Application prospect: can be produced on a large scale and is suitable for fruits, vegetables, grain crops and economic crops, with both fertilizer effect and biological control function. While efficiently changing the organic matter of the land, it also has the functions of rapidly decomposing macromolecular structures of nitrogen, phosphorus and potassium and promoting rapid absorption by crops, increasing the activity and stress resistance of crops, reducing water consumption, reducing the use of traditional pesticides and fertilizers, achieving fast results and obvious yield and quality increase (according to years of experiments on different crops, it can increase yield by 20-100% and increase sweetness by 2-3 degrees), and fundamentally reducing the comprehensive cost of green organic planting, making it lower in cost than the use of chemical pesticides and fertilizers and greater in crop value.

[0221] 4. Application effect: In order to verify the fertilizer effect, the company has carried out the fertilizer effect experiment in Tangshan Fengnan District, Guye District, Fengrun District, Qian'an City, Leling County, Tanghai County, Yutian County, Jixian County, 22 counties in Ningxia, 12 counties in Chongqing and other places for many years. More than 10 kinds of crops are involved in the experiment, and the experimental demonstration area is more than 5000 mu. The chitin microbial fertilizer is used as base fertilizer and topdressing with 75-150 kg / mu. The test results show that the yield per mu of wheat is increased by 8%, the yield per mu of black wheat is increased by 10%, the yield per mu of corn is increased by 15%, the yield per mu of rice is increased by 20%, the yield per mu of peanut is increased by 11%, the yield per mu of melon is increased by 30%, the yield per mu of grape is increased by 10.5%, the yield per mu of peach is increased by 15%, the yield per mu of greenhouse peach is increased by 14.5%, the yield per mu of tomato is increased by 28%, the yield per mu of cucumber is increased by 38%, the yield per mu of celery is increased by 18.5%, and the sweetness of melon, grape and peach is increased by 1-2 degrees. The fly maggot chitin microbial fertilizer has obvious yield-increasing effect, and improves the quality of the product.

[0222] The present application takes fly maggot chitin and beneficial microbial flora as the core, takes high-quality organic matter as the carrier, and develops a fly maggot chitin bio-organic fertilizer with low cost, high fertilizer efficiency and environment-friendly through scientific formula and sufficient fermentation. The fertilizer fully combines the advantages of fly maggot chitin and beneficial microorganisms and the double action of mutual promotion, achieves the combination of quick-acting and slow-acting, forms performance complementation, fully meets the nutrient demand of crops, and has the effects of no pollution, no public harm, long fertilizer efficiency, disease prevention and resistance, and improvement of crop quality, and is an ideal fertilizer for green agriculture and organic agriculture.

[0223] Table 1

[0224]

[0225]

[0226] Table 2

[0227]

[0228] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection required by the present application is defined by the appended claims and their equivalents.

Claims

1. A fly maggot chitin-based bio-organic fertilizer preparation method, comprising the following steps: Step one: raw material pretreatment (1) Extraction and processing of fly maggot chitin: Live fly maggots are starved for 24 hours to remove impurities, then washed and inactivated in boiling water, dried at low temperature, crushed and passed through a mesh, and then enzymatically hydrolyzed with chitinase and cellulase complex enzyme at a specific mass ratio under certain pH and temperature conditions for a certain period of time. After enzyme inactivation, fly maggot chitin is obtained by centrifugal separation; (2) Mixing of organic materials and adjustment of C / N ratio: Mix cow dung, straw and soybean meal at a total mass percentage of 40-60%:20-40%:5-15%, adjust the moisture content to 45-60%, and control the C / N ratio to 20-30 by adding carbon or nitrogen sources; Step two: anaerobic-aerobic combined fermentation Mix 1-5% of the enzymatically hydrolyzed fly maggot chitin, 80-90% of the organic material, 5-10% of the complex microbial agent and 3-8% of the humic acid, and ferment at 50-70℃ and 40-70% humidity for 5-12 days, turning the pile every 12-36 hours; Step three: post-treatment Dry the fermentation product to a moisture content of ≤15%, granulate to 1-5mm particles, spray 0.5-2% anti-caking agent, and package for storage.

2. The bio-organic fertilizer preparation method according to claim 1, characterized in that: Step one: raw material pretreatment (1) Extraction and processing of fly maggot chitin: Live fly maggots are starved for 24 hours to remove impurities, then washed and inactivated in boiling water, dried at low temperature of 60℃, crushed and passed through a 30-60 mesh, and then enzymatically hydrolyzed with chitinase and cellulase complex enzyme at a mass ratio of 4:1.5 at pH 5.5-6.0 and 50-55℃ for 4-6 hours. After enzyme inactivation, fly maggot chitin is obtained by centrifugal separation; (2) Mixing of organic materials and adjustment of C / N ratio: Mix cow dung, straw and soybean meal at a total mass percentage of 50%:30%:10%, and adjust the C / N ratio to 25-30 by adding the remaining 10% of corn cob. Adjust the moisture content of the mixed material to 50-55%; Step two: anaerobic-aerobic combined fermentation Mix the following components at a total mass percentage: Enzymatically hydrolyzed fly maggot chitin: 3%; Organic material: 85%; Complex microbial agent: 7%, of which the live bacterial number of Bacillus subtilis, Trichoderma and photosynthetic bacteria accounts for 30%, 20% and 50% respectively; Humic acid: 5%; Ferment at 55-65℃ and 50-60% humidity for 7-10 days, turning the pile every 24 hours; Step three: post-treatment Dry the fermentation product to a moisture content of ≤10%, granulate to 2-4mm particles, spray 1% diatomite, and package for storage.

3. The method of claim 1, wherein, The enzyme activity of the complex enzyme is: chitinase ≥400U / g, cellulase ≥200U / g.

4. The method of claim 1, wherein, The crushing particle size is 40 mesh, and the enzymatic hydrolysis efficiency is ≥90%.

5. The method of claim 1, wherein, During the fermentation process, the temperature is controlled at 55-65℃, and a forced ventilation system is used.

6. The method of claim 1, wherein, The complex microbial agent contains Bacillus subtilis: viable bacterial count ≥ 1 × 10 9 CFU / g; Trichoderma: spore count ≥ 5 × 10 8 CFU / g; Photosynthetic bacteria: viable bacterial count ≥ 2 × 10 8 CFU / g, and needs to be activated and cultured at 30°C for 24 hours before use.

7. The method of claim 2, wherein, The humic acid is derived from lignite extract, which is crushed to 100 mesh; the specific extraction process is as follows: mix lignite powder with 0.5M NaOH solution at a ratio of 1:5 (w / v), stir at 80℃ for 2 hours, acidify to pH 2.0 after centrifugation, and dry the precipitate and crush it to 100 mesh.

8. The method of claim 1, wherein, The anti-caking agent is diatomite or bentonite, and the particle hardness after spraying is greater than or equal to 5N.

9. A fly maggot chitin-based bio-organic fertilizer, characterized by: The biological organic fertilizer is prepared by the preparation method in claim 1.

10. The fly maggot chitin-based bio-organic fertilizer according to claim 8 is used in the planting of fruits and vegetables, economic crops, and field crops, characterized in that: The dosage of the biological organic fertilizer is 50-200 kg per mu.

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