Marine biological compound fertilizer and its application

Abstract

The invention relates to the technical field of compound fertilizers, and discloses a marine biological compound fertilizer and an application thereof. The marine biological compound fertilizer comprises, by weight, 35-50 parts of a modified coating, 7-12 parts of a mixed microbial agent, and 3-8 parts of a soil improver. The modified coating is obtained by cross-linking modified bentonite-based marine organisms, acrylic acid, and acrylamide under the action of an initiator and a cross-linking agent, has a three-dimensional spatial network structure, can extend the slow-release period of the fertilizer, and improve the action time of the compound fertilizer. The mixed microbial agent can effectively promote crops to absorb essential elements, and more effectively absorb and utilize nutrients in the fertilizer. The soil improver can provide a place for microorganisms to survive and reproduce, and can also improve soil compaction, soil permeability, and soil activity. The marine biological raw materials in the invention are fully obtained by using marine waste, are green and environmentally friendly, realize recycling, and reduce the cost of the marine biological compound fertilizer.

Description

Technical Field

[0001] The invention relates to the technical field of compound fertilizers, in particular to a marine biological compound fertilizer and application thereof. Background Art

[0002] Fertilizer is an indispensable means of production in agriculture and forestry. It can improve soil properties and soil fertility, thereby increasing the yield of crops per unit area. As a large agricultural country, my country needs to consume a large amount of chemical fertilizers every year. Long-term application of chemical fertilizers can easily cause problems such as land acidification and structural changes. At the same time, the production and application of chemical fertilizers can easily pollute the environment. Marine biofertilizers use biological resources such as fish, shrimp, shellfish and algae in the ocean, and after extraction, fermentation and other process treatments, they are used as fertilizers to fertilize the soil. Compared with traditional chemical fertilizers, this fertilizer is more environmentally friendly, can reduce the use of chemical fertilizers, and reduce the pollution of agricultural production to the environment. Secondly, biological fertilizers are rich in organic matter, nitrogen, phosphorus, potassium and other nutrients, which can provide nutrients required for crop growth, and the nutrient release rate is slow, which can meet the needs of long-term crop growth. And it can solve the problems of crop resistance, hardening of cultivated land, soil acidification caused by traditional fertilizers to a certain extent, and at the same time play the role of rooting and promoting rooting, disease resistance and stress resistance, improving crop quality, and increasing crop yield.

[0003] Chinese patent application CN102070372A discloses a marine biological active environmentally friendly fertilizer and a preparation method thereof, the fertilizer is composed of shell powder, silicate bacterial agent and bentonite, and uses shells discarded in coastal areas as a component of the biologically active environmentally friendly fertilizer, which works together with silicate bacterial agent and bentonite to neutralize acidic soil, improve soil permeability, and improve crop quality, but the fertilizer has a single component, poor soil fertilizer effect, and little increase in crop yield. Chinese patent application CN111777463A discloses a marine biological composite fertilizer and a preparation method thereof, the biological composite fertilizer components include seaweed, marine biological residues, fish protein, seaweed polysaccharide, alginic acid, marine biostimulant, ammonium chloride, tricalcium phosphate, zinc sulfate, ferrous sulfate, manganese sulfate, boric acid, magnesium oxide, silicon oxide, microbial agent, the biological composite fertilizer can improve soil compaction problems, poor air permeability and other problems, and can also promote crop growth and increase crop yield, but the fertilizer release speed is fast, the utilization rate is low, and the resistance to pathogens is poor.

[0004] Therefore, it is of great significance to develop a marine biological compound fertilizer that can effectively improve soil structure, has long-lasting fertility and excellent anti-bacterial properties. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a marine biological compound fertilizer and its application. The obtained marine biological compound fertilizer has extremely low damage to the soil, can effectively improve the soil structure, has long-lasting fertility, increases the yield of crops, has excellent anti-pathogen performance, is beneficial to resource utilization, and reduces environmental pollution.

[0006] In order to achieve the above object, the present invention discloses a marine biological compound fertilizer, which comprises 35-50 parts of modified coating, 7-12 parts of mixed microbial agent and 3-8 parts of soil improver by weight.

[0007] Preferably, the soil conditioner consists of shell powder and seaweed powder in a mass ratio of 100:20-30.

[0008] Preferably, the mixed microbial agent consists of Bacillus subtilis, Trichoderma harzianum and Bacillus mucilaginosus in a mass ratio of 100:58-65:90-120.

[0009] The modified envelope is prepared by the following steps:

[0010] S1. Ultrasonic dispersion of sodium bentonite in deionized water, after uniform dispersion, adding γ-aminopropyltriethoxysilane, stirring and mixing, reacting at 45-55° C. for 24-36 hours, after the reaction is completed, filtering, washing with deionized water, and drying in a vacuum drying oven at 60° C. for 12 hours to obtain amino bentonite;

[0011] S2, ultrasonically dispersing the aminated bentonite in N,N-dimethylformamide, and after uniform dispersion, adding 4-aminocinnamic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC·HCl) and 1-hydroxybenzotriazole (HOBt), mixing, reacting, cooling after the reaction, filtering, washing with saturated brine, and vacuum drying at 60°C for 12h to obtain modified bentonite;

[0012] S3, dissolving chitosan in glacial acetic acid solution, mixing evenly, adjusting the pH of the solution to neutral with sodium hydroxide solution, adding formaldehyde sodium alginate and modified bentonite, stirring and mixing, reacting, and after the reaction is completed, freeze-drying to obtain modified bentonite-based marine organisms;

[0013] S4. Evenly mix deionized water, modified bentonite-based marine organisms, acrylic acid, acrylamide, an initiator and a crosslinking agent to react. After the reaction is completed, cool, filter, wash with deionized water, and vacuum dry at 60° C. for 12 hours to obtain a modified coating.

[0014] Preferably, the preparation method of the sodium bentonite in S1 is as follows: ultrasonically disperse the bentonite in deionized water, and after uniform dispersion, add sodium carbonate and stir to mix, wherein the mass ratio of bentonite, deionized water and sodium carbonate is 100:210:105, stir for 24 hours, wash with deionized water, centrifuge at a centrifugal rate of 6000r / min, filter, and dry at 60°C for 12 hours to obtain sodium bentonite.

[0015] Preferably, the mass ratio of sodium bentonite, deionized water and γ-aminopropyltriethoxysilane in S1 is 100:1800-2500:68-75.

[0016] Preferably, the mass ratio of amination bentonite, N,N-dimethylformamide, 4-aminocinnamic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole in S2 is 100:3500-4000:135-150:320-350:150-190.

[0017] Preferably, the reaction temperature in S2 is 30-40° C., and the reaction time is 6-9 h.

[0018] Preferably, the glacial acetic acid solution in S3 is a glacial acetic acid aqueous solution with a mass concentration of 1%.

[0019] Preferably, the preparation method of the formaldehyded sodium alginate in S3 is as follows: a mixed solvent, sodium alginate and sodium periodate are stirred and mixed evenly, wherein the mixed solvent consists of anhydrous ethanol and deionized water in a volume ratio of 1:1, reacting at 30°C for 4 hours under light-proof conditions, and then adding ethylene glycol, wherein the mass ratio of the added mixed solvent, sodium alginate, sodium periodate and ethylene glycol is 2100:100:95:98. After the reaction is completed, pour into anhydrous ethanol for precipitation to obtain formaldehyded sodium alginate.

[0020] Preferably, the mass ratio of chitosan, glacial acetic acid solution, formaldehyded sodium alginate and modified bentonite in S3 is 100:1800-2100:95-120:10-30.

[0021] Preferably, the reaction temperature in S3 is 25-35° C., and the reaction time is 6-9 min.

[0022] Preferably, the mass ratio of deionized water, modified bentonite-based marine organisms, acrylic acid, acrylamide, initiator and crosslinking agent in S4 is 1200-1500:100:15-25:3-5:1-2:18-30.

[0023] Preferably, the reaction temperature in S4 is 65-75° C., and the reaction time is 2-3 h.

[0024] Preferably, the initiator in S4 is potassium persulfate.

[0025] Preferably, the cross-linking agent in S4 is N,N-methylenebisacrylamide.

[0026] Preferably, the marine biological compound fertilizer is used to promote crop growth.

[0027] Chitosan is extracted from the shells of shrimps and crabs, soluble in acidic media, and has the characteristics of biocompatibility, biodegradability, antibacterial properties, and film-forming properties. Sodium alginate is a byproduct of extracting iodine and mannitol from kelp or sargassum of brown algae, and also has excellent biocompatibility and easy degradation. Both are cheap and easy to obtain, can be fully utilized from marine waste, are green and environmentally friendly, realize recycling, and reduce the cost of marine biological compound fertilizers.

[0028] In the present invention, gamma-aminopropyl triethoxysilane is used to modify sodium bentonite, and amino groups are introduced on the surface of sodium bentonite to obtain amino bentonite. The amino bentonite and the carboxyl groups on 4-aminocinnamic acid undergo amidation reaction under the action of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1-hydroxybenzotriazole, and amide bonds, amino groups and carbon-carbon double bonds are introduced on the surface of bentonite to obtain modified bentonite. The amino groups on chitosan and the amino groups on the modified bentonite react with aldehyde-modified sodium alginate to obtain modified bentonite-based marine organisms, and carbon-carbon double bonds are introduced. The modified bentonite-based marine organisms, acrylic acid and acrylamide react under the action of an initiator and a crosslinking agent, and crosslink to obtain a modified coating.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The modified coating prepared in the present invention has a three-dimensional network structure, high strength, and is not easy to break. It can extend the slow-release period of the fertilizer, greatly improve the action time of the compound fertilizer, introduce a large number of hydrophilic groups such as carboxyl groups, and has excellent water retention effect. At the same time, the modified coating is prepared using marine bio-based materials, which is easy to degrade and has good biocompatibility. It can improve the soil structure, prevent the loss of nutrients, and has a positive effect on K + NH 4 + and NO 3 -It has a strong adsorption effect on nutrients such as calcium, phosphorus, and potassium. It also adsorbs trace elements, medium-sized elements, and water, which plays a role in preserving fertilizer, water, and nutrients in the soil for a long time, thereby improving the utilization rate of fertilizers. The added bentonite can absorb and retain nutrients in the fertilizer, making it difficult for it to be lost or volatilized by the soil, slowly releasing nutrients, making the nutritional effect of the fertilizer more lasting, and can extend the nutrient supply time of the fertilizer and improve the efficiency of fertilization. Furthermore, bentonite has excellent air permeability and water retention, which can keep the soil loose and moist, and provide the necessary air and water for the growth of plant roots.

[0031] (2) The mixed microbial agent added in the present invention can effectively promote the absorption of essential elements by crops. Phosphorus and potassium in the soil exist in the form of compounds and are difficult to be directly absorbed and utilized by plants. Bacillus subtilis has the effect of potassium dissolving and can decompose silicate minerals. It can decompose shell powder and provide biological calcium and a large amount of alkaline earth metal elements for crop growth. Bacillus subtilis has the functions of nitrogen fixation, phosphorus dissolving and potassium dissolving. It can convert phosphorus and potassium that are not easily absorbed by crops into phosphorus and potassium that can be directly utilized by plants. At the same time, it can form a probiotic environment in the soil, promote the formation of soil aggregate structure, improve the soil's fertilizer and water retention capacity, increase soil looseness, and be beneficial to root growth. The metabolites contain a variety of antibacterial substances, inhibit the growth and metabolism of harmful microorganisms in the soil, thereby improving the disease resistance of plants, inducing crops to produce substances such as indoleacetic acid, and increasing the level of growth stimulants in crops, thereby promoting plant growth. After being applied to the soil and decomposed by organisms, it can form a kind of humus. The obtained ecological organic fertilizer can effectively improve the soil structure, prevent soil compaction, promote microbial activity, accelerate the degradation of organic matter, promote plant growth, and improve the quality of agricultural products. Trichoderma harzianum has a broad spectrum of antibacterial properties and can effectively prevent and treat a variety of fungal diseases and soil-borne diseases. It works together with chitosan to give compound fertilizers excellent antibacterial effects. Microbial agents can improve the absorption and utilization rate of marine biological compound fertilizers, allowing crops to more effectively absorb and utilize nutrients in fertilizers.

[0032] (3) The shell powder and seaweed powder in the present invention contain a variety of trace elements, which can well meet the needs of crop growth. The soil conditioner used has a strong adsorption capacity. When applied to the soil, it has a strong ventilation and water holding capacity, can provide a place for microorganisms to survive and reproduce, and can also improve soil compaction, soil permeability and soil activity. The raw materials used in the present invention are low in cost and easy to obtain. They are renewable materials, and the process formula is simple. The various components complement and promote each other, and synergistically enhance the effect. The resulting marine biological compound fertilizer has extremely low damage to the soil, can effectively improve the soil structure, make the soil loose and breathable, can improve soil fertility, and can inhibit pathogenic microorganisms in the soil. The fertility is long-lasting and can increase the yield of crops. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The present invention is a flow chart for preparing marine biological compound fertilizer;

[0034] Figure 2 The present invention is a flow chart for preparing the modified envelope. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] Embodiment 1: A marine biological compound fertilizer, comprising 35 parts of modified coating, 7 parts of mixed microbial agents, and 3 parts of soil improver, in parts by mass, wherein the mixed microbial agent is composed of Bacillus subtilis, Trichoderma harzianum and Bacillus mucilaginosus in a mass ratio of 100:58:90, and the soil improver is composed of shell powder and seaweed powder in a mass ratio of 100:20.

[0037] The modified coating is prepared by the following steps:

[0038] S1. Ultrasonic dispersion of sodium bentonite in deionized water, after uniform dispersion, adding γ-aminopropyltriethoxysilane, stirring and mixing, wherein the mass ratio of the added sodium bentonite, deionized water, and γ-aminopropyltriethoxysilane is 100:1800:68, reacting at 45° C. for 36 h. After the reaction is completed, filtering, washing with deionized water, and drying in a vacuum drying oven at 60° C. for 12 h to obtain amino bentonite;

[0039] S2, ultrasonically dispersing the aminated bentonite in N,N-dimethylformamide, after uniform dispersion, adding 4-aminocinnamic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole, mixing, wherein the mass ratio of aminated bentonite, N,N-dimethylformamide, 4-aminocinnamic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole is 100:3500:135:320:150, reacting, the reaction temperature is 30°C, the reaction time is 9h, after the reaction is completed, cooling, filtering, washing with saturated brine, and vacuum drying at 60°C for 12h to obtain modified bentonite;

[0040] S3, dissolving chitosan in a glacial acetic acid aqueous solution with a mass concentration of 1%, mixing evenly, adjusting the pH of the solution to neutral with a sodium hydroxide solution, adding formaldehyde sodium alginate and modified bentonite, stirring and mixing, wherein the mass ratio of the added chitosan, glacial acetic acid solution, formaldehyde sodium alginate, and modified bentonite is 100:1800:95:10, reacting at 25°C for 9 minutes, and after the reaction is completed, freeze-drying to obtain a modified bentonite-based marine organism;

[0041] S4. Evenly mix deionized water, modified bentonite-based marine organisms, acrylic acid, acrylamide, initiator potassium persulfate and crosslinking agent N,N-methylenebisacrylamide in a mass ratio of 1200:100:15:3:1:18, react at 65°C for 3 hours, cool and filter after the reaction, wash with deionized water, and vacuum dry at 60°C for 12 hours to obtain a modified coating.

[0042] Example 2: A marine biological compound fertilizer, comprising 38 parts of modified coating, 9 parts of mixed microbial agents, and 5 parts of soil conditioner, calculated by mass. The mixed microbial agent consists of Bacillus subtilis, Trichoderma harzianum and Bacillus mucilaginosus in a mass ratio of 100:62:112, and the soil conditioner consists of shell powder and seaweed powder in a mass ratio of 100:27.

[0043] The modified coating is prepared by the following steps:

[0044] S1. Ultrasonic dispersion of sodium bentonite in deionized water, after uniform dispersion, adding γ-aminopropyltriethoxysilane, stirring and mixing, wherein the mass ratio of the added sodium bentonite, deionized water and γ-aminopropyltriethoxysilane is 100:2100:70, reacting at 50° C. for 30 h. After the reaction is completed, filtering, washing with deionized water, and drying in a vacuum drying oven at 60° C. for 12 h to obtain amino bentonite;

[0045] S2, ultrasonically dispersing the aminated bentonite in N,N-dimethylformamide, after uniform dispersion, adding 4-aminocinnamic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole, mixing, wherein the mass ratio of aminated bentonite, N,N-dimethylformamide, 4-aminocinnamic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole is 100:3600:140:330:165, reacting, the reaction temperature is 35°C, the reaction time is 7h, after the reaction is completed, cooling, filtering, washing with saturated brine, and vacuum drying at 60°C for 12h to obtain modified bentonite;

[0046] S3, dissolving chitosan in a glacial acetic acid aqueous solution with a mass concentration of 1%, mixing evenly, adjusting the pH of the solution to neutral with a sodium hydroxide solution, adding formaldehyde sodium alginate and modified bentonite, stirring and mixing, wherein the mass ratio of the added chitosan, glacial acetic acid solution, formaldehyde sodium alginate, and modified bentonite is 100:1900:105:15, reacting at 30° C. for 7 minutes, and after the reaction is completed, freeze-drying to obtain a modified bentonite-based marine organism;

[0047] S4. Evenly mix deionized water, modified bentonite-based marine organisms, acrylic acid, acrylamide, initiator potassium persulfate and crosslinking agent N,N-methylenebisacrylamide in a mass ratio of 1300:100:18:3.5:1.4:21, react at 70°C for 2.4 hours, cool after the reaction, filter, wash with deionized water, and vacuum dry at 60°C for 12 hours to obtain a modified coating.

[0048] Example 3: A marine biological compound fertilizer, comprising 38 parts of modified coating, 9 parts of mixed microbial agents, and 5 parts of soil improver, by mass. The mixed microbial agent consists of Bacillus subtilis, Trichoderma harzianum and Bacillus mucilaginosus in a mass ratio of 100:62:112, and the soil improver consists of shell powder and seaweed powder in a mass ratio of 100:27.

[0049] The modified coating is prepared by the following steps:

[0050] S1. Ultrasonic dispersion of sodium bentonite in deionized water, after uniform dispersion, adding γ-aminopropyltriethoxysilane, stirring and mixing, wherein the mass ratio of the added sodium bentonite, deionized water, and γ-aminopropyltriethoxysilane is 100:2400:72, reacting at 50° C. for 32 hours, after the reaction is completed, filtering, washing with deionized water, and drying in a vacuum drying oven at 60° C. for 12 hours to obtain amino bentonite;

[0051] S2, ultrasonically dispersing the aminated bentonite in N,N-dimethylformamide, after uniform dispersion, adding 4-aminocinnamic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole, mixing, wherein the mass ratio of aminated bentonite, N,N-dimethylformamide, 4-aminocinnamic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole is 100:3800:145:340:180, reacting, the reaction temperature is 35° C., the reaction time is 8 h, after the reaction is completed, cooling, filtering, washing with saturated brine, and vacuum drying at 60° C. for 12 h to obtain modified bentonite;

[0052] S3, dissolving chitosan in a glacial acetic acid aqueous solution with a mass concentration of 1%, mixing evenly, adjusting the solution pH to neutral with a sodium hydroxide solution, adding formaldehyde sodium alginate and modified bentonite, stirring and mixing, wherein the mass ratio of the added chitosan, glacial acetic acid solution, formaldehyde sodium alginate, and modified bentonite is 100:2000:115:25, reacting at 30° C. for 8 min, and after the reaction is completed, freeze-drying to obtain a modified bentonite-based marine organism;

[0053] S4. Evenly mix deionized water, modified bentonite-based marine organisms, acrylic acid, acrylamide, initiator potassium persulfate and cross-linking agent N,N-methylenebisacrylamide in a mass ratio of 1400:100:22:4.5:1.8:26, react at 70°C for 2.5 hours, cool after the reaction, filter, wash with deionized water, and vacuum dry at 60°C for 12 hours to obtain a modified coating.

[0054] Example 4: A marine biological compound fertilizer, comprising 45 parts of modified coating, 10 parts of mixed microbial agents, and 7 parts of soil conditioner, by mass. The mixed microbial agent consists of Bacillus subtilis, Trichoderma harzianum and Bacillus subtilis in a mass ratio of 100:62:112, and the soil conditioner consists of shell powder and seaweed powder in a mass ratio of 100:27.

[0055] The preparation method of the modified coating is the same as the preparation method of the modified coating in Example 3.

[0056] Example 5: A marine biological compound fertilizer, comprising 50 parts of modified coating, 12 parts of mixed microbial agents, and 8 parts of soil conditioner, by mass. The mixed microbial agent consists of Bacillus subtilis, Trichoderma harzianum and Bacillus mucilaginosus in a mass ratio of 100:65:120, and the soil conditioner consists of shell powder and seaweed powder in a mass ratio of 100:30.

[0057] The modified coating is prepared by the following steps:

[0058] S1. Ultrasonic dispersion of sodium bentonite in deionized water, after uniform dispersion, adding γ-aminopropyltriethoxysilane, stirring and mixing, wherein the mass ratio of the added sodium bentonite, deionized water, and γ-aminopropyltriethoxysilane is 100:2500:75, reacting at 55° C. for 24 h. After the reaction is completed, filtering, washing with deionized water, and drying in a vacuum drying oven at 60° C. for 12 h to obtain amino bentonite;

[0059] S2, ultrasonically dispersing the aminated bentonite in N,N-dimethylformamide, after uniform dispersion, adding 4-aminocinnamic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole, mixing, wherein the mass ratio of aminated bentonite, N,N-dimethylformamide, 4-aminocinnamic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole is 100:4000:150:350:190, reacting, the reaction temperature is 40°C, the reaction time is 6h, after the reaction is completed, cooling, filtering, washing with saturated brine, and vacuum drying at 60°C for 12h to obtain modified bentonite;

[0060] S3, dissolving chitosan in a glacial acetic acid aqueous solution with a mass concentration of 1%, mixing evenly, adjusting the pH of the solution to neutral with a sodium hydroxide solution, adding formaldehyde sodium alginate and modified bentonite, stirring and mixing, wherein the mass ratio of the added chitosan, glacial acetic acid solution, formaldehyde sodium alginate, and modified bentonite is 100:2100:120:30, reacting at 35°C for 6min, and after the reaction is completed, freeze-drying to obtain a modified bentonite-based marine organism;

[0061] S4. Evenly mix deionized water, modified bentonite-based marine organisms, acrylic acid, acrylamide, initiator potassium persulfate and crosslinking agent N,N-methylenebisacrylamide in a mass ratio of 1500:100:25:5:2:30, react at 75°C for 2 hours, cool after the reaction, filter, wash with deionized water, and vacuum dry at 60°C for 12 hours to obtain a modified coating.

[0062] Comparative Example 1

[0063] A marine biological compound fertilizer comprises 52 parts of modified coating and 10 parts of mixed microbial agents, wherein the mixed microbial agents are composed of Bacillus subtilis, Trichoderma harzianum and Bacillus mucilaginosus in a mass ratio of 100:62:112.

[0064] The preparation method of the modified coating is the same as the preparation method of the modified coating in Example 3.

[0065] Comparative Example 2

[0066] A marine biological compound fertilizer comprises 55 parts of modified coating and 7 parts of soil conditioner by weight, wherein the soil conditioner is composed of shell powder and seaweed powder in a weight ratio of 100:27.

[0067] The preparation method of the modified coating is the same as the preparation method of the modified coating in Example 3.

[0068] Comparative Example 3

[0069] A marine biological compound fertilizer comprises, by weight, 45 parts of modified bentonite-based marine organisms, 10 parts of mixed microbial agents, and 7 parts of soil improvers, wherein the mixed microbial agents consist of Bacillus subtilis, Trichoderma harzianum, and Bacillus mucilaginosus in a weight ratio of 100:62:112, and the soil improver consists of shell powder and seaweed powder in a weight ratio of 100:27.

[0070] The modified bentonite-based marine organisms are prepared by the following steps:

[0071] S1. Ultrasonic dispersion of sodium bentonite in deionized water, after uniform dispersion, adding γ-aminopropyltriethoxysilane, stirring and mixing, wherein the mass ratio of the added sodium bentonite, deionized water, and γ-aminopropyltriethoxysilane is 100:2400:72, reacting at 50° C. for 32 hours, after the reaction is completed, filtering, washing with deionized water, and drying in a vacuum drying oven at 60° C. for 12 hours to obtain amino bentonite;

[0072] S2. Dissolve chitosan in a glacial acetic acid aqueous solution with a mass concentration of 1%, mix evenly, use sodium hydroxide solution to adjust the pH of the solution to neutral, then add formaldehyde sodium alginate and modified bentonite, stir and mix, wherein the mass ratio of the added chitosan, glacial acetic acid solution, formaldehyde sodium alginate, and modified bentonite is 100:2000:115:25, react at 30°C for 8 minutes, and after the reaction is completed, freeze-dry to obtain modified bentonite-based marine organisms.

[0073] Chitosan (deacetylation degree 85%, average molecular weight 1800kDa) in the embodiments and comparative examples of the present invention was purchased from Qingdao Yunzhou Biotechnology Co., Ltd.; bentonite was purchased from Xinglong Bentonite Factory, Fangzi District, Weifang City, with item number 01; Bacillus subtilis was purchased from Jinan Qinghai Chemical Co., Ltd., with effective live bacteria ≥20 billion / g; Trichoderma harzianum was purchased from Jinan Qinghai Chemical Co., Ltd., with effective live bacteria ≥10 billion / g; Bacillus colloidus was purchased from Jinan Jinyuyuan Biotechnology Co., Ltd., with effective live bacteria ≥10 billion / g; sodium alginate was purchased from Sinopharm Chemical Reagent Co., Ltd.; shell powder was purchased from Zhuhai Ocean Shell Processing Plant; seaweed was purchased from Qingdao Haixingyuan Biotechnology Co., Ltd., and the seaweed consisted of red algae and enteromorpha in a mass ratio of 1:1. After being washed with tap water twice, it was rinsed with deionized water 5 times, and then placed in a 60°C drying oven for 24 hours, and then crushed and ground, and passed through a 60-mesh sieve to obtain seaweed powder; other reagents are commercially available.

[0074] The marine biological compound fertilizers prepared in Examples 1-5 and Comparative Examples 1-3 were named Sample 1, Sample 2, Sample 3, Sample 4, Sample 5, Sample 6, Sample 7, and Sample 8, respectively, and were subjected to corresponding tests. The test methods and test results are as follows:

[0075] (1) After long-term multi-point tests, the demonstration results show that applying 50-80 kg of the marine biological compound fertilizer of the present invention per mu can effectively improve soil structure and increase crop yields. The specific field test control effect is as follows: rice is selected as the experimental crop. Under the condition that other fertilizer amounts remain unchanged, 60 kg of marine biological compound fertilizer is applied per mu of rice field as base fertilizer. On the basis of the blank sample without adding marine biological compound fertilizer, the rice yield increase is shown in Table 1:

[0076] Table 1

[0077] test Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Sample 7 Sample 8 Yield increase (%) 4.5 5.2 5.6 5.8 6.1 3.3 4.0 5.3

[0078] According to the results recorded in Table 1, when other fertilizer application amounts remain unchanged, applying 60 kg of marine biological compound fertilizer corresponding to samples 1-5 per mu of rice field as base fertilizer can increase the yield by 6.1%; no soil conditioner was added to sample 6, and the absorption and utilization of fertilizer by rice was greatly reduced, and the fertility was weakened, and the increase in yield was reduced; no mixed microbial agent was added to sample 7, and the absorption and utilization of fertilizer by rice was reduced to 4.0%; modified bentonite-based marine organisms were directly added to sample 8 without further modification of the modified bentonite-based marine organisms, and the yield increase was 5.3%.

[0079] (2) Accurately weigh 0.5 g of sample particles and immerse them in 1000 mL of deionized water. Allow them to swell for 60 min at room temperature, filter through an 80-mesh non-woven fabric, and weigh the swollen materials separately. Then calculate the mass ratio before and after swelling, which is the water absorption rate. The test results are shown in Table 2:

[0080] Table 2

[0081] test Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Sample 7 Sample 8 Water absorption rate (g / g) 881 912 937 953 960 741 904 722

[0082] According to the results recorded in Table 2, the marine biological compound fertilizers corresponding to samples 1-5 have excellent water absorption, indicating that the marine biological organic fertilizer has excellent water retention. No soil conditioner was added to sample 6, and the water absorption was greatly reduced; no mixed microbial agent was added to sample 7, which had little effect on the water absorption; modified bentonite-based marine organisms were directly added to sample 8 without further modification of the modified bentonite-based marine organisms, and the water absorption was as low as 722g / g.

[0083] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A marine biological compound fertilizer, characterized in that: By weight, it includes 35-50 parts of modified coating, 7-12 parts of mixed microbial agent, and 3-8 parts of soil conditioner; The mixed microbial agent is composed of Bacillus subtilis, Trichoderma harzianum and Bacillus mucilaginosus in a mass ratio of 100:58-65:90-120; The modified envelope is prepared by the following steps: S1. Ultrasonic dispersion of sodium bentonite in deionized water, after uniform dispersion, adding γ-aminopropyltriethoxysilane, stirring and mixing, reacting at 45-55° C. for 24-36 hours, after the reaction is completed, filtering, washing, and drying to obtain amino bentonite; S2, ultrasonically dispersing the aminated bentonite in N,N-dimethylformamide, and after uniform dispersion, adding 4-aminocinnamic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole, mixing, reacting, and after the reaction is completed, cooling, filtering, washing, and drying to obtain modified bentonite; S3, dissolving chitosan in glacial acetic acid solution, mixing evenly, adjusting the pH of the solution to neutral with sodium hydroxide solution, adding formaldehyde sodium alginate and modified bentonite, stirring and mixing, reacting, and after the reaction is completed, freeze-drying to obtain modified bentonite-based marine organisms; S4, mixing deionized water, modified bentonite-based marine organisms, acrylic acid, acrylamide, an initiator and a crosslinking agent uniformly, reacting, cooling, filtering, washing and drying after the reaction to obtain a modified coating; The mass ratio of amination bentonite, N,N-dimethylformamide, 4-aminocinnamic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole in S2 is 100:3500-4000:135-150:320-350:150-190, the reaction temperature is 30-40° C., and the reaction time is 6-9 h; The preparation method of the aldehyded sodium alginate in S3 is as follows: a mixed solvent, sodium alginate and sodium periodate are stirred and mixed evenly, wherein the mixed solvent consists of anhydrous ethanol and deionized water in a volume ratio of 1:1, reacting at 30° C. for 4 hours under light-proof conditions, and then adding ethylene glycol, wherein the mass ratio of the added mixed solvent, sodium alginate, sodium periodate and ethylene glycol is 2100:100:95:98, and after the reaction is completed, pouring into anhydrous ethanol for precipitation to obtain aldehyded sodium alginate; The mass ratio of chitosan, glacial acetic acid solution, formaldehyded sodium alginate and modified bentonite in S3 is 100:1800-2100:95-120:10-30.

2. A marine biological compound fertilizer according to claim 1, characterized in that: The soil conditioner consists of shell powder and seaweed powder in a mass ratio of 100:20-30.

3. A marine biological compound fertilizer according to claim 1, characterized in that: The reaction temperature in S3 is 25-35° C., and the reaction time is 6-9 min.

4. A marine biological compound fertilizer according to claim 1, characterized in that: The mass ratio of deionized water, modified bentonite-based marine organisms, acrylic acid, acrylamide, initiator and crosslinking agent in S4 is 1200-1500:100:15-25:3-5:1-2:18-30.

5. The marine biological compound fertilizer according to claim 1, characterized in that: The reaction temperature in S4 is 65-75° C., and the reaction time is 2-3 h.

6. A marine biological compound fertilizer according to claim 1, characterized in that: In the S4, the initiator is potassium persulfate, and the cross-linking agent is N,N-methylenebisacrylamide.

7. Use of the marine biological compound fertilizer according to any one of claims 1 to 6 in promoting crop growth.

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