Composition containing amino-oligosaccharin and preparation method thereof

Abstract

The invention relates to the technical field of fertilizers, in particular to an amino-oligosaccharin-containing composition and a preparation method thereof.The amino-oligosaccharin-containing composition is prepared from an amino-oligosaccharin compound, amino-oligosaccharin compound particles and auxiliary particles; the amino-oligosaccharin compound is prepared from straw powder, amino-oligosaccharin, monopotassium phosphate, polyglutamic acid and urea; the amino-oligosaccharin composite particles are prepared from an amino-oligosaccharin compound, a straw extract, starch and an acrylate monomer, the straw extract is prepared from straw powder and 1, 4-dioxane; the auxiliary particles are prepared from an amino-oligosaccharin compound, oxidized starch, carboxymethyl chitosan and glycerol; the amino-oligosaccharin-containing composition prepared by the preparation method disclosed by the invention is more stable in acting effect, the utilization rate of the fertilizer is effectively improved, and meanwhile, the biological activity potential of amino-oligosaccharin is fully exerted, so that the amino-oligosaccharin-containing composition has a wider application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of fertilizers, and in particular to an amino oligosaccharide composition and a preparation method thereof. Background Art

[0002] Aminoligosaccharides, also known as chitosan oligosaccharides for agriculture, are natural polysaccharide products extracted from the shells of marine organisms such as shrimps and crabs (D-glucosamine oligosaccharides connected by β-1,4 glycosidic bonds) and are obtained by degradation of chitin to chitosan. Aminoligosaccharides are an environmentally friendly biological pesticide that can ensure crop safety and solve environmental pollution problems. After application, they can be degraded by soil microorganisms into water, carbon dioxide and other substances, and have the characteristics of no residue and no pollution. Studies have shown that aminooligosaccharides can promote plant growth and development to a certain extent. The plant resistance spectrum induced by them is broad and long-lasting. Long-term or multiple inductions will not cause plant resistance. They can also improve the immunity of plants to biological and abiotic stresses, thereby achieving the purpose of crop disease resistance and harm reduction, improving the drought resistance of rye, and increasing yield.

[0003] Therefore, it has been used in some fertilizer preparations containing amino oligosaccharides, such as a special fertilizer for sunflower disclosed in patent technical document CN106927918A, which is composed of the following components by weight: 20-25 parts of straw, 10-20 parts of sawdust, 10-12 parts of expanded perlite powder, 1-2 parts of nitrification inhibitor DMPP, 0.3-0.5 parts of tea saponin, 26-28 parts of potassium nitrate, 21-23 parts of dregs fertilizer, 20-22 parts of calcium magnesium phosphate fertilizer, 18-20 parts of urea, 7-9 parts of amino oligosaccharides, 5-7 parts of photosynthetic bacterial fertilizer, 2-4 parts of Bacillus preparation, 3-5 parts of decomposition crop straw preparation, 6-8 parts of humic acid compound fertilizer, 2-5 parts of boric slag, and 1-3 parts of zinc carbonate.

[0004] However, these existing technical solutions are usually prepared by directly mixing amino oligosaccharides with other chemical fertilizers. However, this simple mixing method has obvious disadvantages: first, the interaction between amino oligosaccharides and chemical fertilizer components is unstable, which can easily lead to the loss of effective ingredients; second, the fertilizer utilization rate is not high and may have a negative impact on the soil environment; third, the preparation process is simple, lacks scientific proportions and fine processing, and it is difficult to fully exert the biological activity potential of amino oligosaccharides.

[0005] Therefore, according to the above-mentioned related technologies, it is urgent to develop an amino oligosaccharide composition and a preparation method thereof. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide an amino-oligosaccharide composition and a preparation method thereof, so as to solve the problem that the amino-oligosaccharide composition prepared by the prior art is difficult to fully exert the effect of the amino-oligosaccharide and the stability of the effect is poor.

[0007] Based on the above objectives, the present invention provides an amino oligosaccharide composition and a preparation method thereof.

[0008] An amino oligosaccharide composition, comprising the following raw materials in parts by weight: 15-20 parts of an amino oligosaccharide complex, 50-60 parts of amino oligosaccharide composite microparticles, and 25-30 parts of auxiliary particles;

[0009] The amino oligosaccharide complex is prepared from straw powder, amino oligosaccharide, potassium dihydrogen phosphate, polyglutamic acid and urea;

[0010] The amino oligosaccharide composite particles are prepared from amino oligosaccharide complex, straw extract, oxidized starch, methyl methacrylate and butyl acrylate;

[0011] The straw extract is prepared from straw powder and 1,4-dioxane;

[0012] The auxiliary particles are prepared from amino oligosaccharide complex, oxidized starch, carboxymethyl chitosan and glycerol.

[0013] Preferably, the preparation method of the amino oligosaccharide complex is as follows:

[0014] The straw powder is carbonized at 500-700°C for 2-3 hours, and after being cooled to room temperature, it is mixed with amino oligosaccharides, potassium dihydrogen phosphate, polyglutamic acid, and urea, and then ultrasonicated at 90-100kH for 45-50 minutes to obtain an amino oligosaccharide complex.

[0015] Preferably, the mass ratio of the straw powder, amino oligosaccharide, potassium dihydrogen phosphate, polyglutamic acid and urea is 103-120:1:5:1:15-16;

[0016] The straw powder is obtained by crushing any one of wheat straw, rice straw, corn straw or a mixture thereof.

[0017] Preferably, the straw extract preparation method is as follows:

[0018] Step A1. Mix straw powder, 1,4-dioxane, water and concentrated sulfuric acid, stir at 175-185°C and 1-1.1 MPa for 2-2.5 h, and filter after cooling to room temperature to obtain a solid residue and a filtrate;

[0019] Step A2. Add water to 1,4-dioxane and heat to 55-65°C, then use it to wash the solid residue 3-5 times, combine the washing liquid and the filtrate, add 2.5-3 times the volume of deionized water, let it stand for 20-30 hours, then filter, and dry the filter residue to obtain the straw extract.

[0020] Preferably, the mass ratio of the straw powder, 1,4-dioxane, water and concentrated sulfuric acid in step A1 is 10-12:54-57:26-28:1.35-1.5; the mass ratio of 1,4-dioxane, water and solid residue in step A2 is 17.5-20 mL:2.5-3 mL:3-5 g.

[0021] Preferably, the preparation method of the amino oligosaccharide composite microparticles is as follows:

[0022] Step B1. dissolving the straw extract and maleic anhydride in deionized water, then adjusting the pH to 9-10, stirring at 360-400 r / min for 6-7 hours at 45-50°C, adjusting the pH to 1-2 after cooling to room temperature, standing for 3-5 hours, filtering and washing the filter residue with deionized water for 5-7 times, and then drying at 55-60°C to obtain a modified straw extract;

[0023] Step B2. Add the modified straw extract and oxidized starch to deionized water, stir at 300-400 r / min for 1-1.5 h at 87-90° C., add methyl methacrylate, butyl acrylate, amino oligosaccharide complex and emulsifier after the temperature drops to 45-50° C., and stir at 500-550 r / min for 3-4 h to obtain a mixed solution;

[0024] Step B3. Add potassium persulfate solution to the mixed solution at 75-80°C at 0.3-0.5 mL / min, adjust the pH to 7-8, and stir at 250-260 r / min for 4-4.5 h to obtain an emulsion;

[0025] Step B4. Dry the emulsion at 80-85°C, then crush and sieve to obtain amino oligosaccharide composite microparticles with a particle size of 4-7 mm.

[0026] Preferably, the mass ratio of the straw extract to maleic anhydride in step B1 is 10-12:10-12;

[0027] The mass ratio of the modified straw extract, oxidized starch, deionized water, methyl methacrylate, butyl acrylate, amino oligosaccharide complex and emulsifier in step B2 is 4.79-4.9: 15.96-16.5: 100-120: 4-4.1: 7.1-7.4: 20-25: 1.4-1.45;

[0028] The mass ratio of the potassium persulfate solution to the mixed solution in step B3 is 13.3-15:150-170;

[0029] The concentration of the potassium persulfate solution in step B3 is 6wt%-6.1wt%;

[0030] The particle size of the amino oligosaccharide composite microparticles is 4-7 mm.

[0031] Preferably, the preparation method of the auxiliary particles is as follows:

[0032] The amino oligosaccharide complex, oxidized starch and carboxymethyl chitosan are dissolved in deionized water, and then 7-8.5 g of glycerol is added, stirred at 700-800 r / min for 15-20 min, gelled at 75-80° C. for 60-70 min, and then crushed and sieved to obtain auxiliary particles.

[0033] Preferably, the mass ratio of the amino oligosaccharide complex, oxidized starch, carboxymethyl chitosan, deionized water and glycerol is 6-7:12.5-15:12.5-15:25-30:7-8.5;

[0034] The particle size of the auxiliary particles is 3-5 mm.

[0035] A method for preparing an amino-oligosaccharide composition, the method for preparing the amino-oligosaccharide composition is as follows:

[0036] The amino-oligosaccharide complex, the amino-oligosaccharide complex microparticles and the auxiliary particles are evenly mixed to obtain an amino-oligosaccharide-containing composition.

[0037] Beneficial effects of the present invention:

[0038] The invention provides an amino-oligosaccharide composition and a preparation method thereof. The invention directly compounds activated carbon prepared by heat-treating straw powder with amino-oligosaccharide, potassium dihydrogen phosphate, polyglutamic acid and urea, which can effectively improve the stability and persistence of the amino-oligosaccharide and urea after mixing, and can also promote plant growth and development to the greatest extent; the acrylate monomer can form a copolymer with the amino-oligosaccharide complex, straw extract and starch, and the straw extract can increase the cross-linking degree and polymer density of the polyacrylate film, thereby improving the sustained-release capacity of urea and amino-oligosaccharide in the composition, and at the same time, the amino-oligosaccharide, potassium dihydrogen phosphate and polyglutamic acid compounded in a specific ratio can effectively improve the anti-epidemic resistance of crops; wherein, auxiliary particles with a specific particle size can make the fertility stable for a long time; compared with the prior art, the amino-oligosaccharide composition prepared by the invention has a more stable effect and realizes a stable interaction between the amino-oligosaccharide and components such as urea, effectively improves the fertilizer utilization rate, and gives full play to the biological activity potential of the amino-oligosaccharide, and therefore has a broader application prospect. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0040] Example 1: A method for preparing an amino oligosaccharide composition is as follows:

[0041] S1. Crush wheat straw to obtain straw powder;

[0042] S2. 103 g of straw powder was carbonized at 500 ° C for 2 h, and after cooling to room temperature, it was mixed with 1 g of amino oligosaccharide, 5 g of potassium dihydrogen phosphate, 1 g of polyglutamic acid, and 15 g of urea, and then ultrasonicated at 90 kH for 45 min to obtain an amino oligosaccharide complex;

[0043] S3. 10 g of straw powder, 54 g of 1,4-dioxane, 26 g of water and 1.35 g of concentrated sulfuric acid were mixed and stirred at 175 ° C and 1 MPa for 2 h. After cooling to room temperature, the mixture was filtered to obtain a solid residue and a filtrate.

[0044] S4. Add 2.5 mL of water to 17.5 mL of 1,4-dioxane and heat to 55°C, then use it to wash 3 g of solid residue three times, combine the washing liquid with the filtrate, add 2.5 times the volume of deionized water, let it stand for 20 hours, filter, and dry the residue to obtain the straw extract;

[0045] S5. 10 g of straw extract and 10 g of maleic anhydride were dissolved in 80 g of deionized water, and then the pH was adjusted to 9 with 1 mol / L sodium hydroxide solution, stirred at 360 r / min at 45 ° C for 6 h, and after cooling to room temperature, the pH was adjusted to 1 with 1.8 mol / L sulfuric acid solution; after standing for 3 h, the filter was filtered and the filter residue was washed with deionized water 5 times, and then dried at 55 ° C to obtain a modified straw extract;

[0046] S6. 4.79 g of modified straw extract and 15.96 g of oxidized starch were added to 100 g of deionized water, and stirred at 300 r / min for 1 h at 87 ° C. After the temperature dropped to 45 ° C, 4 g of methyl methacrylate, 7.1 g of butyl acrylate, 20 g of amino oligosaccharide complex and 1.4 g of emulsifier were added, and stirred at 500 r / min for 3 h to obtain a mixed solution;

[0047] S7. 13.3 g of a 6 wt% potassium persulfate solution was added dropwise to 150 g of the mixed solution at 75 ° C at 0.3 mL / min, and then the pH was adjusted to 7 with aqueous ammonia, and then stirred at 250 r / min for 4 h to obtain an emulsion;

[0048] S8. drying the emulsion at 80°C, and then crushing and sieving to obtain amino oligosaccharide composite particles with a particle size of 4-7 mm;

[0049] S9. 6 g of amino oligosaccharide complex, 12.5 g of oxidized starch and 12.5 g of carboxymethyl chitosan were dissolved in 25 g of deionized water, and then 7 g of glycerol was added, stirred at 700 r / min for 15 min, gelled at 75° C. for 60 min, and then crushed and sieved to obtain auxiliary particles with a particle size of 3-5 mm;

[0050] S10. 15 g of the amino oligosaccharide complex, 50 g of the amino oligosaccharide composite particles and 25 g of the auxiliary particles were mixed to obtain an amino oligosaccharide-containing composition;

[0051] Example 2: A method for preparing an amino oligosaccharide composition is as follows:

[0052] S1. crushing rice straw to obtain straw powder;

[0053] S2. 108 g of straw powder was carbonized at 550°C for 2.5 h, and after cooling to room temperature, it was mixed with 1 g of amino oligosaccharide, 5 g of potassium dihydrogen phosphate, 1 g of polyglutamic acid, and 15.3 g of urea, and then ultrasonicated at 93 kH for 47 min to obtain an amino oligosaccharide complex;

[0054] S3. 10.5 g of straw powder, 55 g of 1,4-dioxane, 26.8 g of water and 1.4 g of concentrated sulfuric acid were mixed and stirred at 178 ° C and 1 MPa for 2.2 h. After cooling to room temperature, the mixture was filtered to obtain a solid residue and a filtrate.

[0055] S4. Add 2.7 mL of water to 18 mL of 1,4-dioxane and heat to 59°C, then use it to wash 3.5 g of solid residue 4 times, combine the washing liquid and the filtrate, add 2.5 times the volume of deionized water, let it stand for 24 hours, filter, and dry the residue to obtain the straw extract;

[0056] S5. 10.8 g of straw extract and 10.8 g of maleic anhydride were dissolved in 88 g of deionized water, and then the pH was adjusted to 9.5 with 1 mol / L sodium hydroxide solution, stirred at 370 r / min at 47°C for 6.3 h, and after cooling to room temperature, the pH was adjusted to 1.5 with 1.8 mol / L sulfuric acid solution; after standing for 3.5 h, the mixture was filtered and the residue was washed with deionized water for 5 times, and then dried at 57°C to obtain a modified straw extract;

[0057] S6. 4.82 g of modified straw extract and 16.1 g of oxidized starch were added to 108 g of deionized water, stirred at 88 ° C and 330 r / min for 1.2 h, and after the temperature dropped to 47 ° C, 4.05 g of methyl methacrylate, 7.2 g of butyl acrylate, 22 g of amino oligosaccharide complex and 1.42 g of emulsifier were added, and stirred at 520 r / min for 3.3 h to obtain a mixed solution;

[0058] S7. 13.8 g of a 6.05 wt% potassium persulfate solution was added dropwise at 0.4 mL / min to 157 g of the mixed solution at 77 ° C, and then the pH was adjusted to 7.5 with aqueous ammonia, and then stirred at 255 r / min for 4.2 h to obtain an emulsion;

[0059] S8. drying the emulsion at 82°C, and then crushing and sieving to obtain amino oligosaccharide composite particles with a particle size of 4-7 mm;

[0060] S9. 6.3 g of amino oligosaccharide complex, 13 g of oxidized starch and 13 g of carboxymethyl chitosan were dissolved in 26 g of deionized water, and then 7.5 g of glycerol was added, stirred at 730 r / min for 17 min, gelled at 77° C. for 63 min, and then crushed and sieved to obtain auxiliary particles with a particle size of 3-5 mm;

[0061] S10. 17 g of the amino oligosaccharide complex, 53 g of the amino oligosaccharide composite particles and 27 g of the auxiliary particles were mixed to obtain an amino oligosaccharide-containing composition;

[0062] Example 3: A method for preparing an amino oligosaccharide composition is as follows:

[0063] S1. crushing corn stalks to obtain stalk powder;

[0064] S2. 115 g of straw powder was carbonized at 650 ° C for 2.5 h, and after cooling to room temperature, it was mixed with 1 g of amino oligosaccharide, 5 g of potassium dihydrogen phosphate, 1 g of polyglutamic acid, and 15.6 g of urea, and then ultrasonicated at 97 kH for 48 min to obtain an amino oligosaccharide complex;

[0065] S3. 11.5 g of straw powder, 56 g of 1,4-dioxane, 27.5 g of water and 1.45 g of concentrated sulfuric acid were mixed and stirred at 182 ° C and 1.1 MPa for 2.3 h, and then cooled to room temperature and filtered to obtain a solid residue and a filtrate;

[0066] S4. Add 2.8 mL of water to 19 mL of 1,4-dioxane and heat to 62°C, then use it to wash 4.5 g of solid residue 4 times, combine the washing liquid and the filtrate, add 3 times the volume of deionized water, let it stand for 28 hours, filter, and dry the residue to obtain the straw extract;

[0067] S5. 11.2 g of straw extract and 11.2 g of maleic anhydride were dissolved in 95 g of deionized water, and then the pH was adjusted to 9.5 with 1 mol / L sodium hydroxide solution, stirred at 390 r / min at 48°C for 6.7 h, and after cooling to room temperature, the pH was adjusted to 1.5 with 1.8 mol / L sulfuric acid solution; after standing for 4.5 h, the residue was filtered and washed with deionized water for 6 times, and then dried at 58°C to obtain a modified straw extract;

[0068] S6. 4.85 g of modified straw extract and 16.3 g of oxidized starch were added to 115 g of deionized water, stirred at 89 ° C and 370 r / min for 1.3 h, and after the temperature dropped to 50 ° C, 4.1 g of methyl methacrylate, 7.3 g of butyl acrylate, 23 g of amino oligosaccharide complex and 1.43 g of emulsifier were added, and stirred at 530 r / min for 3.7 h to obtain a mixed solution;

[0069] S7. 14.5 g of a 6.1 wt% potassium persulfate solution was added dropwise to 165 g of the mixed solution at 77 ° C at 0.4 mL / min, and then the pH was adjusted to 8 with aqueous ammonia, and then stirred at 258 r / min for 4.3 h to obtain an emulsion;

[0070] S8. drying the emulsion at 83°C, and then crushing and sieving to obtain amino oligosaccharide composite particles with a particle size of 4-7 mm;

[0071] S9. 6.7 g of amino oligosaccharide complex, 14 g of oxidized starch and 14 g of carboxymethyl chitosan were dissolved in 28 g of deionized water, and then 8 g of glycerol was added, stirred at 780 r / min for 18 min, gelled at 78° C. for 68 min, and then crushed and sieved to obtain auxiliary particles with a particle size of 3-5 mm;

[0072] S10. 18 g of the amino oligosaccharide complex, 58 g of the amino oligosaccharide composite particles and 29 g of the auxiliary particles were mixed to obtain an amino oligosaccharide-containing composition;

[0073] Example 4: A method for preparing an amino oligosaccharide composition is as follows:

[0074] S1. Grinding a mixture of wheat straw, rice straw and corn straw to obtain straw powder;

[0075] S2. 120 g of straw powder was carbonized at 700°C for 3 h, and after cooling to room temperature, it was mixed with 1 g of amino oligosaccharide, 5 g of potassium dihydrogen phosphate, 1 g of polyglutamic acid, and 16 g of urea, and then ultrasonicated at 100 kHz for 45-50 min to obtain an amino oligosaccharide complex;

[0076] S3. 12 g of straw powder, 57 g of 1,4-dioxane, 28 g of water and 1.5 g of concentrated sulfuric acid were mixed and stirred at 185 ° C and 1.1 MPa for 2.5 h, and then cooled to room temperature and filtered to obtain a solid residue and a filtrate;

[0077] S4. Add 3 mL of water to 20 mL of 1,4-dioxane and heat to 65°C, then use it to wash 5 g of solid residue 5 times, combine the washing liquid and the filtrate, add 3 times the volume of deionized water, let it stand for 30 hours, filter, and dry the residue to obtain the straw extract;

[0078] S5. 12 g of straw extract and 12 g of maleic anhydride were dissolved in 100 g of deionized water, and then the pH was adjusted to 10 with 1 mol / L sodium hydroxide solution, stirred at 400 r / min at 50°C for 7 h, and after cooling to room temperature, the pH was adjusted to 2 with 1.8 mol / L sulfuric acid solution; after standing for 5 h, the mixture was filtered and the residue was washed with deionized water 7 times, and then dried at 60°C to obtain a modified straw extract;

[0079] S6. 4.9 g of modified straw extract and 16.5 g of oxidized starch were added to 120 g of deionized water, stirred at 400 r / min at 90 ° C for 1.5 h, and after the temperature dropped to 50 ° C, 4.1 g of methyl methacrylate, 7.4 g of butyl acrylate, 25 g of amino oligosaccharide complex and 1.45 g of emulsifier were added, and stirred at 550 r / min for 4 h to obtain a mixed solution;

[0080] S7. -15 g of a 6.1 wt% potassium persulfate solution was added dropwise to 170 g of the mixed solution at 80 ° C at 0.5 mL / min, and then the pH was adjusted to 8 with aqueous ammonia, and then stirred at 260 r / min for 4.5 h to obtain an emulsion;

[0081] S8. drying the emulsion at 85°C, and then crushing and sieving to obtain amino oligosaccharide composite particles with a particle size of 4-7 mm;

[0082] S9. 7 g of amino oligosaccharide complex, 15 g of oxidized starch and 15 g of carboxymethyl chitosan were dissolved in 30 g of deionized water, and then 8.5 g of glycerol was added, stirred at 800 r / min for 20 min, gelled at 80° C. for 70 min, and then crushed and sieved to obtain auxiliary particles with a particle size of 3-5 mm;

[0083] S10. 20 g of the amino oligosaccharide complex, 60 g of the amino oligosaccharide composite particles and 30 g of the auxiliary particles were mixed to obtain an amino oligosaccharide-containing composition;

[0084] Comparative Example 1:

[0085] Compared with Example 1, this comparative example only replaces the "2g amino oligosaccharide, 15g urea" added in the preparation process of the amino oligosaccharide complex with "0.2g amino oligosaccharide, 15g urea", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally obtains an amino oligosaccharide-containing composition;

[0086] Comparative Example 2:

[0087] Compared with Example 1, this comparative example only replaces the "amino oligosaccharide complex" added in the preparation process of the amino oligosaccharide composition with "amino oligosaccharide and urea mixture", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally obtains the amino oligosaccharide composition;

[0088] Comparative Example 3:

[0089] Compared with Example 1, this comparative example only replaces the "amino oligosaccharide complex" added in the preparation process of the amino oligosaccharide-containing composition with "amino oligosaccharide", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally obtains the amino oligosaccharide-containing composition;

[0090] Comparative Example 4:

[0091] Compared with Example 1, this comparative example only replaces the "amino oligosaccharide complex" added in the preparation process of the amino oligosaccharide composition with "amino oligosaccharide composite particles", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally obtains the amino oligosaccharide composition;

[0092] Comparative Example 5:

[0093] Compared with Example 1, this comparative example only replaces the "modified straw extract" added in the preparation process of the mixed solution with "straw extract", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally obtains an amino oligosaccharide composition;

[0094] Comparative Example 6:

[0095] Compared with Example 1, the modified straw extract was not added in the preparation process of the mixed solution in this comparative example, and the remaining steps and parameters were the same, which will not be repeated in this comparative example, and finally an amino oligosaccharide composition was obtained;

[0096] Comparative Example 7:

[0097] Compared with Example 1, this comparative example did not add oxidized starch during the preparation of the mixed solution, and the remaining steps and parameters were the same, which will not be repeated in this comparative example. Finally, an amino oligosaccharide composition was obtained;

[0098] Comparative Example 8:

[0099] Compared with Example 1, this comparative example did not add methyl methacrylate and butyl acrylate during the preparation of the mixed solution, and the remaining steps and parameters were the same, which will not be repeated in this comparative example, and finally an amino oligosaccharide composition was obtained;

[0100] Comparative Example 9:

[0101] Compared with Example 1, this comparative example only replaces the "auxiliary particles with a particle size of 3-5 mm" with "auxiliary particles with a particle size of 0.5-1 mm", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally obtains an amino oligosaccharide composition;

[0102] Comparative Example 10:

[0103] Compared with Example 1, this comparative example only replaces the "auxiliary particles" added in the preparation process of the amino-oligosaccharide composition with "amino-oligosaccharide composite particles", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally obtains the amino-oligosaccharide composition;

[0104] Comparative Example 11:

[0105] Compared with Example 1, this comparative example only replaces the "15g amino-oligosaccharide complex, 50g amino-oligosaccharide composite microparticles and 25g auxiliary particles" added in the preparation process of the amino-oligosaccharide composition with "50g amino-oligosaccharide complex, 25g amino-oligosaccharide composite microparticles and 15g auxiliary particles", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally the amino-oligosaccharide composition is obtained;

[0106] Performance Test:

[0107] Sustained release performance:

[0108] Referring to the standard of "GB / T23348-2009 Slow-release Fertilizer", 5.0 g of the amino-oligosaccharide composition prepared in Examples 1 to 4 and Comparative Examples 1 to 11 were weighed and put into a nylon mesh bag, which was placed in a beaker containing 1000 mL of deionized water and allowed to stand, covered and sealed, and placed in an electrically heated constant temperature incubator at 25±0.5°C for culture. Before each sampling, the nylon bag was taken out and the solution was stirred evenly. After sampling, the excess solution was poured out and 1000 mL of new deionized water was poured again. The solution sample was stored in a 10 mL centrifuge tube, and the 1d nutrient release rate, 10d nutrient release rate, 20d nutrient release rate and 30d nutrient release rate of nitrogen element of the amino-oligosaccharide composition prepared in Examples 1 to 4 and Comparative Examples 1 to 11 were measured;

[0109] 1d nutrient release rate calculation formula:

[0110] 1d nutrient release rate (%) = (nitrogen release in 1d / total nitrogen content in the composition) × 100%

[0111] 10d nutrient release rate calculation formula:

[0112] 10d nutrient release rate (%) = (nitrogen release within 10d / total nitrogen content in the composition) × 100%

[0113] Calculation formula for 20d nutrient release rate:

[0114] 20d nutrient release rate (%) = (nitrogen release within 20d / total nitrogen content in the composition) × 100%

[0115] Calculation formula for 30d nutrient release rate:

[0116] 30d nutrient release rate (%) = (nitrogen release within 30d / total nitrogen content in the composition) × 100%

[0117] Determination of nitrogen leaching rate:

[0118] According to the standard of "HJ636-2012 Determination of total nitrogen in water quality by alkaline potassium persulfate digestion ultraviolet spectrophotometry", 2.0g of the amino oligosaccharide composition prepared in Examples 1 to 4 and Comparative Examples 1 to 11 were weighed respectively, and evenly mixed with 200g of soil after drying, and the mixture was placed in a 25°C constant temperature culture container, and 100mL of deionized water was added to the soil every week. The soil leachate was collected and stored in a centrifuge tube, and the total nitrogen content in the leachate was measured after 6 weeks to obtain the nitrogen leaching rate of the amino oligosaccharide composition; the measurement results are shown in Table 1;

[0119] The calculation formula of nitrogen leaching rate is:

[0120] Nitrogen leaching rate (%) = (total nitrogen content in the leaching solution / total nitrogen content applied to the soil) × 100%

[0121] Table 1

[0122]

[0123]

[0124] Data Analysis:

[0125] As can be seen from Table 1, the amino oligosaccharide composition prepared by the present invention has a more stable effect and utilization rate of effective ingredients;

[0126] This may be because the present invention directly compounds the activated carbon prepared by heat treatment of straw powder with amino-oligosaccharides and urea, which can effectively improve the stability and persistence of the mixture of amino-oligosaccharides and urea. Since amino-oligosaccharides can promote plant cell division and growth, improve plant photosynthesis efficiency, etc., when amino-oligosaccharides and urea are mixed in a specific ratio in the present invention, the absorption and utilization of urea by plants can be promoted to the maximum extent, and the role of amino-oligosaccharides can be maximized, thereby promoting plant growth and development to the maximum extent. At the same time, the mixing in a specific ratio of the present invention can also enable amino-oligosaccharides to alleviate the fertilizer damage caused by urea to plants to the maximum extent; at the same time, the amino-oligosaccharides, potassium dihydrogen phosphate, and polyglutamic acid compounded in a specific ratio can effectively improve the anti-epidemic resistance of crops;

[0127] The acrylic acid ester monomer added in the present invention can form a copolymer with the amino-oligosaccharide complex, the straw extract and the starch, thereby greatly enhancing the urea slow-release ability of the overall composition; the straw extract can increase the cross-linking degree and polymer density of the polyacrylate film, thereby improving the slow-release ability of urea and amino-oligosaccharide in the composition and the slow-release performance and stability of urea and amino-oligosaccharide in water; the oxidized starch can improve the stability of the amino-oligosaccharide composite particles, and at the same time adsorb and fix the nutrients in the fertilizer, reduce the nutrient leaching rate, and thus improve the utilization rate of the effective ingredients;

[0128] Among them, the auxiliary particles of a specific particle size can play a role in moisture-proof and quality preservation during storage, and play a role in regulating the overall fertilizer effect of the amino-oligosaccharide-containing composition to be long-term, efficient and stable after application. This may be because the auxiliary particles of a specific particle size selected by the present invention can exert a predetermined fertilizer effect when the fertilizer effect of the amino-oligosaccharide complex decreases and before the fertilizer effect of the amino-oligosaccharide composite microparticles reaches the maximum value, so that the fertility can be long-term stable;

[0129] The present invention also regulates the dosage ratio of the amino oligosaccharide complex, the amino oligosaccharide composite microparticles and the auxiliary particles, and selects a specific ratio with the most stable effect and the highest utilization rate of the effective ingredients for compounding;

[0130] Therefore, the amino-oligosaccharide composition prepared by the present invention has a more stable effect and realizes a stable interaction between the amino-oligosaccharides and components such as urea, effectively improving the fertilizer utilization rate and giving full play to the biological activity potential of the amino-oligosaccharides.

[0131] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0132] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An amino oligosaccharide composition, characterized in that: The method comprises the following raw materials in parts by weight: 15-20 parts of amino oligosaccharide complex, 50-60 parts of amino oligosaccharide complex microparticles, and 25-30 parts of auxiliary particles; The amino oligosaccharide complex is prepared from straw powder, amino oligosaccharide, potassium dihydrogen phosphate, polyglutamic acid and urea; The amino oligosaccharide composite particles are prepared from amino oligosaccharide complex, straw extract, oxidized starch, methyl methacrylate and butyl acrylate; The straw extract is prepared from straw powder and 1,4-dioxane; The auxiliary particles are prepared from amino oligosaccharide complex, oxidized starch, carboxymethyl chitosan and glycerol.

2. The amino oligosaccharide composition according to claim 1, characterized in that The preparation method of the amino oligosaccharide complex is as follows: The straw powder is carbonized at 500-700°C for 2-3 hours, and after being cooled to room temperature, it is mixed with amino oligosaccharides, potassium dihydrogen phosphate, polyglutamic acid, and urea, and then ultrasonicated at 90-100kH for 45-50 minutes to obtain an amino oligosaccharide complex.

3. The amino oligosaccharide composition according to claim 2, characterized in that The mass ratio of the straw powder, amino oligosaccharide, potassium dihydrogen phosphate, polyglutamic acid and urea is 103-120:1:5:1:15-16; The straw powder is obtained by crushing any one of wheat straw, rice straw, corn straw or a mixture thereof.

4. The amino oligosaccharide composition according to claim 1, characterized in that The straw extract preparation method is as follows: Step A1. Mix straw powder, 1,4-dioxane, water and concentrated sulfuric acid, stir at 175-185°C and 1-1.1 MPa for 2-2.5 h, and filter after cooling to room temperature to obtain a solid residue and a filtrate; Step A2. Add water to 1,4-dioxane and heat to 55-65° C., then use it to wash the solid residue 3-5 times, combine the washing liquid with the filtrate, filter and dry the filter residue to obtain the straw extract.

5. The amino oligosaccharide composition according to claim 4, characterized in that The mass ratio of the straw powder, 1,4-dioxane, water and concentrated sulfuric acid in step A1 is 10-12:54-57:26-28:1.35-1.5; the mass ratio of 1,4-dioxane, water and solid residue in step A2 is 17.5-20 mL:2.5-3 mL:3-5 g.

6. The amino oligosaccharide composition according to claim 1, characterized in that The preparation method of the amino oligosaccharide composite microparticles is as follows: Step B1. dissolving the straw extract and maleic anhydride in deionized water, then adjusting the pH to 9-10, stirring at 360-400 r / min for 6-7 hours at 45-50°C, adjusting the pH to 1-2 after cooling to room temperature, standing for 3-5 hours, filtering and washing the filter residue with deionized water for 5-7 times, and then drying at 55-60°C to obtain a modified straw extract; Step B2. Add the modified straw extract and oxidized starch to deionized water, stir at 300-400 r / min for 1-1.5 h at 87-90° C., add methyl methacrylate, butyl acrylate, amino oligosaccharide complex and emulsifier after the temperature drops to 45-50° C., and stir at 500-550 r / min for 3-4 h to obtain a mixed solution; Step B3. Add potassium persulfate solution to the mixed solution at 75-80°C at 0.3-0.5 mL / min, adjust the pH to 7-8, and stir at 250-260 r / min for 4-4.5 h to obtain an emulsion; Step B4. Dry the emulsion at 80-85°C, then crush and sieve to obtain amino oligosaccharide composite microparticles with a particle size of 4-7 mm.

7. The amino oligosaccharide composition according to claim 6, characterized in that The mass ratio of the straw extract to maleic anhydride in step B1 is 10-12:10-12; The mass ratio of the modified straw extract, oxidized starch, deionized water, methyl methacrylate, butyl acrylate, amino oligosaccharide complex and emulsifier in step B2 is 4.79-4.9: 15.96-16.5: 100-120: 4-4.1: 7.1-7.4: 20-25: 1.4-1.45; The mass ratio of the potassium persulfate solution to the mixed solution in step B3 is 13.3-15:150-170; The concentration of the potassium persulfate solution in step B3 is 6wt%-6.1wt%; The particle size of the amino oligosaccharide composite microparticles is 4-7 mm.

8. The amino oligosaccharide composition according to claim 1, characterized in that The preparation method of the auxiliary particles is as follows: The amino oligosaccharide complex, oxidized starch and carboxymethyl chitosan are dissolved in deionized water, and then 7-8.5 g of glycerol is added, stirred at 700-800 r / min for 15-20 min, gelled at 75-80° C. for 60-70 min, and then crushed and sieved to obtain auxiliary particles.

9. The amino oligosaccharide composition according to claim 8, characterized in that The mass ratio of the amino oligosaccharide complex, oxidized starch, carboxymethyl chitosan, deionized water and glycerol is 6-7:12.5-15:12.5-15:25-30:7-8.5; The particle size of the auxiliary particles is 3-5 mm.

10. A method for preparing the amino oligosaccharide composition according to any one of claims 1 to 9, characterized in that: The preparation method of the amino oligosaccharide composition is as follows: The amino-oligosaccharide complex, the amino-oligosaccharide complex microparticles and the auxiliary particles are evenly mixed to obtain an amino-oligosaccharide-containing composition.

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