Seaweed extract-functional microorganism composite slow-release fertilizer and preparation method thereof

Abstract

The invention relates to the technical field of agricultural fertilizers, discloses a seaweed extract-functional microorganism compound slow-release fertilizer and a preparation method thereof, and solves the problems in the background art. The seaweed extract is a compound containing enteromorpha polysaccharide and alginic acid extract; the functional microorganism is a complex microbial inoculant composed of phosphate solubilizing bacteria, nitrogen-fixing bacteria, phosphate solubilizing bacteria and bacillus; the slow-release carrier is prepared by coating the seaweed extract and the functional microorganisms with sodium alginate-chitosan microcapsules; the signal molecule is selected from at least one of polyamine substances and jasmonic acid methyl ester; the fertilizer has the advantages that the utilization rate of the fertilizer can be increased, growth and reproduction of soil microorganisms are promoted, the stress resistance of crops is improved, and the requirements of different soil types and planting environments can be met.

Description

Technical Field

[0001] The present invention belongs to the technical field of agricultural fertilizers, and specifically relates to a seaweed extract-functional microorganism composite slow-release fertilizer and a preparation method thereof. Background Art

[0002] Traditional slow-release fertilizers mostly rely on chemical coating technology, which has problems such as low microbial survival rate and asynchronous nutrient release.

[0003] Although existing seaweed fertilizers can provide organic matter, they lack synergistic slow-release with functional microorganisms and have limited effect on improving crop stress resistance. To this end, we proposed a seaweed extract-functional microorganism composite slow-release fertilizer and its preparation method. Summary of the Invention

[0004] In order to solve the problems raised in the background technology, the present invention provides the following technical solutions: a seaweed extract-functional microorganism composite slow-release fertilizer and a preparation method thereof, comprising the following components:

[0005] Seaweed extract: Contains a complex of Enteromorpha polysaccharide and alginic acid extract;

[0006] Functional microorganisms: a composite microbial agent consisting of phosphate-solubilizing bacteria, nitrogen-fixing bacteria, phosphate-dissolving bacteria and Bacillus;

[0007] Sustained-release carrier: encapsulating the seaweed extract and functional microorganisms through sodium alginate-chitosan microcapsules;

[0008] Signal molecule: at least one selected from polyamines and methyl jasmonate;

[0009] Trace elements: compounds of zinc and boron.

[0010] Preferably, the mass ratio of the Enteromorpha polysaccharide to the alginic acid extract is 1:0.5-2.

[0011] Preferably, the total viable count of the functional microorganisms is 1×10^8-5×10^9 CFU / g, and the mixed volume ratio of phosphate-solubilizing bacteria, nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and Bacillus is 1:1:1:1.

[0012] Preferably, the mass ratio of sodium alginate to chitosan is 2:1-5:1, the microcapsule particle size is 100-500 μm, the mass concentration of the sodium alginate solution is 2%, the concentration of the CaCl2 solution used for coating and curing is 1.5%, and the concentration of the chitosan solution is 0.5%.

[0013] Preferably, the polyamine substance is one or more of putrescine, spermidine or spermine, and the added amount of methyl jasmonate is 0.01-0.1 wt %.

[0014] Preferably, the zinc is added in the form of zinc sulfate, and the boron is added in the form of boric acid, the mass ratio of zinc to boron is 1:0.2-0.8, and the zinc sulfate and boric acid account for 0.1% and 0.04% of the total mass of the fertilizer, respectively.

[0015] Preferably, the slow-release fertilizer granules are prepared by spray drying and have a particle size of 1-3 mm.

[0016] Preferably, the microcapsule coating process includes: dispersing the seaweed extract and the bacterial agent in a sodium alginate solution, dripping a CaCl2 solution into the solution to form gel microspheres, and then coating the microspheres with a chitosan solution for the second time.

[0017] Preferably, the fertilizer is suitable for saline-alkali soil with an electrical conductivity of ≥4 dS / m.

[0018] The specific steps include:

[0019] Enteromorpha polysaccharide and alginic acid are respectively extracted with alkali and acid and then mixed according to the proportion;

[0020] Functional microorganisms were cultured to 1×10^9 CFU / mL and then mixed in equal volumes;

[0021] The seaweed extract and bacterial agent were dispersed in sodium alginate solution and coated with CaCl2 and chitosan to form microcapsules;

[0022] After adding signal molecules and trace elements, spray drying and granulation are carried out.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] Through the sodium alginate-chitosan microcapsule embedding technology, the synergistic slow release of nutrients and microbial agents is achieved. It can slowly release nutrients and microbial agents according to the soil environment and crop needs, improve fertilizer utilization rate, and extend the effective period of fertilizer;

[0025] Seaweed extract is rich in various nutrients and bioactive substances, which can improve soil structure, increase soil organic matter content, promote the growth and reproduction of soil microorganisms, and thus enhance soil fertility;

[0026] The added polyamines and jasmonic acid and its derivative methyl jasmonate act as signal molecules to regulate the physiological metabolism of crops, improve their stress resistance, especially their resistance to salt and alkali, and help them grow in saline-alkali and arid areas.

[0027] This fertilizer is suitable for facility agriculture and arid areas, can meet the needs of different soil types and planting environments, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 This is a flow chart of the preparation steps of the present invention; DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all 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.

[0031] Depend on Figure 1 Given, the present invention includes the following components:

[0032] Seaweed extract: Contains a complex of Enteromorpha polysaccharide and alginic acid extract;

[0033] Functional microorganisms: a composite microbial agent consisting of phosphate-solubilizing bacteria, nitrogen-fixing bacteria, phosphate-dissolving bacteria and Bacillus;

[0034] Sustained-release carrier: sodium alginate-chitosan microcapsules encapsulate seaweed extracts and functional microorganisms;

[0035] Signal molecule: at least one selected from polyamines and methyl jasmonate;

[0036] Trace elements: compounds of zinc and boron.

[0037] The mass ratio of Enteromorpha polysaccharide to alginate extract is 1:0.5-2.

[0038] The total viable count of functional microorganisms is 1×10^8-5×10^9 CFU / g, and the mixed volume ratio of phosphate-solubilizing bacteria, nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and Bacillus is 1:1:1:1.

[0039] The mass ratio of sodium alginate to chitosan is 2:1-5:1, the particle size of the microcapsule is 100-500 μm, the mass concentration of the sodium alginate solution is 2%, the concentration of the CaCl2 solution used for coating and solidification is 1.5%, and the concentration of the chitosan solution is 0.5%.

[0040] The polyamine substance is one or more of putrescine, spermidine or spermine, and the added amount of methyl jasmonate is 0.01-0.1wt%.

[0041] Zinc is added in the form of zinc sulfate, and boron is added in the form of boric acid. The mass ratio of zinc to boron is 1:0.2-0.8, and the zinc sulfate and boric acid account for 0.1% and 0.04% of the total mass of the fertilizer respectively.

[0042] The slow-release fertilizer granules are prepared by spray drying and have a particle size of 1-3 mm.

[0043] The microcapsule coating process includes: dispersing seaweed extract and bacterial agent in sodium alginate solution, adding CaCl2 solution to form gel microspheres, and then coating them with chitosan solution for the second time.

[0044] The fertilizer is suitable for saline-alkali soil with an electrical conductivity of ≥4dS / m.

[0045] The following steps are involved:

[0046] Enteromorpha polysaccharide and alginic acid are respectively extracted with alkali and acid and then mixed according to the proportion;

[0047] Functional microorganisms were cultured to 1×10^9 CFU / mL and then mixed in equal volumes;

[0048] The seaweed extract and bacterial agent were dispersed in sodium alginate solution and coated with CaCl2 and chitosan to form microcapsules;

[0049] After adding signal molecules and trace elements, spray drying and granulation are carried out.

[0050] Preparation method:

[0051] S1 Preparation of seaweed extract: Enteromorpha polysaccharide and alginate extract are extracted separately, Enteromorpha and brown algae are washed and crushed respectively, and then appropriate extraction processes, such as hot water extraction, enzymatic method, etc., are used to extract Enteromorpha polysaccharide and alginate extract respectively. After filtering, concentration and other steps, pure polysaccharide extract and alginate extract are obtained, wherein: Enteromorpha polysaccharide is extracted by alkali extraction and ethanol precipitation; alginate is extracted by acid extraction; Enteromorpha polysaccharide and alginate are mixed in a mass ratio of 1:0.5-2.

[0052] S2 functional microbial expansion: phosphate-solubilizing bacteria, nitrogen-fixing bacteria, phosphate-dissolving bacteria and Bacillus are expanded and inoculated into suitable culture media respectively. They are cultured under specific temperature, humidity and ventilation conditions to allow the bacteria to multiply in large quantities and obtain a high-concentration bacterial solution, wherein: phosphate-solubilizing bacteria, nitrogen-fixing bacteria, phosphate-dissolving bacteria and Bacillus are fermented and cultured respectively until the viable cell count reaches 1×10^9 CFU / mL; and the composite bacterial agent is prepared by mixing them in a volume ratio of 1:1:1:1.

[0053] S3 microcapsule encapsulation process: Sodium alginate-chitosan microcapsule encapsulation technology is used to encapsulate the extracted polysaccharides, alginic acid extracts and expanded bacterial liquid. First, the polysaccharides, alginic acid extracts and bacterial liquid are mixed evenly, and then added to the sodium alginate solution to form a uniform mixed liquid. The mixed liquid is then dripped into a solidifying liquid containing chitosan. Microcapsules are formed through ionic cross-linking to achieve the encapsulation of nutrients and bacterial agents. Among them: the seaweed extract and the composite bacterial agent are dispersed in a sodium alginate solution with a mass concentration of 2%; then added dropwise to a 1.5% CaCl2 solution to form gel microspheres; and then a 0.5% chitosan solution is used for secondary coating and solidification.

[0054] S4 Granulation and Component Addition: Granulate the embedded microcapsules by extrusion granulation, spray drying granulation, etc. to obtain particles with a certain particle size. Then, dry the particles to make their moisture content reach an appropriate range to obtain the final composite slow-release fertilizer product, wherein 0.01-0.1wt% methyl jasmonate, zinc sulfate (Zn mass proportion 0.1%) and boric acid (B mass proportion 0.04%) are added to the microcapsules; spray drying is performed to form particles with a particle size of 1-3mm.

[0055] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0056] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A seaweed extract-functional microorganism composite slow-release fertilizer and a preparation method thereof, characterized by: Includes the following components: Seaweed extract: Contains a complex of Enteromorpha polysaccharide and alginic acid extract; Functional microorganisms: a composite microbial agent consisting of phosphate-solubilizing bacteria, nitrogen-fixing bacteria, phosphate-dissolving bacteria and Bacillus; Sustained-release carrier: encapsulating the seaweed extract and functional microorganisms through sodium alginate-chitosan microcapsules; Signal molecule: at least one selected from polyamines and methyl jasmonate; Trace elements: compounds of zinc and boron.

2. The seaweed extract-functional microorganism composite slow-release fertilizer and its preparation method according to claim 1, characterized in that: The mass ratio of the Enteromorpha polysaccharide to the alginic acid extract is 1:0.5-2.

3. The seaweed extract-functional microorganism composite slow-release fertilizer and its preparation method according to claim 1, characterized in that: The total viable count of the functional microorganisms is 1×10^8-5×10^9 CFU / g, and the mixed volume ratio of phosphate-solubilizing bacteria, nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Bacillus is 1:1:1:

1.

4. The seaweed extract-functional microorganism composite slow-release fertilizer and its preparation method according to claim 1, characterized in that: The mass ratio of sodium alginate to chitosan is 2:1-5:1, the particle size of the microcapsule is 100-500 μm, the mass concentration of the sodium alginate solution is 2%, the concentration of the CaCl2 solution used for coating and solidification is 1.5%, and the concentration of the chitosan solution is 0.5%.

5. The seaweed extract-functional microorganism composite slow-release fertilizer and its preparation method according to claim 1, characterized in that: The polyamine substance is one or more of putrescine, spermidine or spermine, and the added amount of methyl jasmonate is 0.01-0.1 wt %.

6. The seaweed extract-functional microorganism composite slow-release fertilizer and its preparation method according to claim 1, characterized in that: The zinc is added in the form of zinc sulfate, and the boron is added in the form of boric acid. The mass ratio of zinc to boron is 1:0.2-0.8, and the zinc sulfate and boric acid account for 0.1% and 0.04% of the total mass of the fertilizer respectively.

7. The seaweed extract-functional microorganism composite slow-release fertilizer and its preparation method according to claim 1, characterized in that: The slow-release fertilizer granules are prepared by spray drying and have a particle size of 1-3 mm.

8. The seaweed extract-functional microorganism composite slow-release fertilizer and its preparation method according to claim 1, characterized in that: The microcapsule coating process includes: dispersing seaweed extract and bacterial agent in sodium alginate solution, dripping CaCl2 solution to form gel microspheres, and then secondary coating with chitosan solution.

9. The seaweed extract-functional microorganism composite slow-release fertilizer and its preparation method according to claim 1, characterized in that: The fertilizer is suitable for saline-alkali soil with an electrical conductivity of ≥4 dS / m.

10. The method for preparing the slow-release fertilizer according to any one of claims 1 to 9, characterized in that: The following steps are involved: Enteromorpha polysaccharide and alginic acid are respectively extracted with alkali and acid and then mixed according to the proportion; Functional microorganisms were cultured to 1×10^9 CFU / mL and then mixed in equal volumes; The seaweed extract and bacterial agent were dispersed in sodium alginate solution and coated with CaCl2 and chitosan to form microcapsules; After adding signal molecules and trace elements, spray drying and granulation are carried out.

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