Water-soluble fertilizer containing silkworm pupa protein as well as preparation method and application of water-soluble fertilizer

Abstract

The invention discloses a water-soluble fertilizer containing silkworm pupa protein as well as a preparation method and application of the water-soluble fertilizer, and belongs to the technical field of fertilizers. The nutrient solution is prepared from the following components: 10 to 25 percent of silkworm chrysalis protein, 1 to 3 percent of alginic acid oligosaccharide, 0.6 to 1.2 percent of magnesium sulfate, 6 to 8 percent of monopotassium phosphate, 5 to 10 percent of ammonium dihydrogen phosphate, 1 to 1.2 percent of gelatinized corn flour, 0.05 to 0.1 percent of polyaspartic acid and the balance of water. The silkworm chrysalis protein, the alginic acid oligosaccharide and the polyaspartic acid are innovatively subjected to ternary synergistic compounding, the technical breakthrough of integrating soil improvement, stress resistance improvement and quality optimization is realized in the water-soluble fertilizer, and the biomass of crops can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of fertilizers, and in particular relates to a water-soluble fertilizer containing silkworm pupa protein and a preparation method and application thereof. Background Art

[0002] Water-soluble fertilizer is an efficient and convenient type of fertilizer, but there are still some problems with the water-soluble fertilizer in the existing technology:

[0003] Single nutrient composition: Traditional water-soluble fertilizers are mainly inorganic salts, focusing mainly on macroelements such as nitrogen, phosphorus, and potassium. They lack organic components and trace elements that are beneficial to crop growth and do not meet the organic-inorganic synergistic enhancement mechanism.

[0004] Insufficient solubility and stability: Some water-soluble fertilizers become less soluble under high concentration or low temperature conditions, and are prone to precipitation or crystallization, affecting the fertilization effect; in addition, nitrogen is easy to volatilize / leach, and phosphorus and potassium are easily fixed by the soil.

[0005] Limited improvement to soil environment: Most water-soluble fertilizers only focus on the supply of crop nutrients, and have little effect on improving soil microbial activity and soil structure. Long-term use may lead to soil compaction or acidification.

[0006] Cost and cost-effectiveness: Some high-efficiency water-soluble fertilizers have high costs due to the addition of special ingredients or the use of complex processes, which limits their widespread application. For example, animal protein in current water-soluble fertilizers mostly uses high-cost raw materials such as fish protein, and the hydrolysis process is complicated.

[0007] Insufficient functionality: Current water-soluble fertilizers lack natural biostimulants and have limited effect on improving crop resistance.

[0008] Insufficient environmental friendliness: Some water-soluble fertilizers may cause environmental pollution during production and use, such as containing heavy metals or harmful substances. Summary of the invention

[0009] To solve the above technical problems, the present invention proposes a water-soluble fertilizer containing silkworm pupa protein and a preparation method and application thereof. The water-soluble fertilizer containing silkworm pupa protein of the present invention is a low-cost, high-utilization-rate, environmentally friendly water-soluble fertilizer having a biostimulation function.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] One of the technical solutions of the present invention:

[0012] The invention provides a water-soluble fertilizer containing silkworm pupa protein. The water-soluble fertilizer consists of the following components in percentage by mass: 10-25% of silkworm pupa protein, 1-3% of alginate oligosaccharide, 0.6-1.2% of magnesium sulfate, 6-8% of potassium dihydrogen phosphate, 5-10% of ammonium dihydrogen phosphate, 1-1.2% of gelatinized corn flour, 0.05-0.1% of polyaspartic acid, and the balance is water.

[0013] Silkworm pupa protein can be directly absorbed by crop roots or leaves as a nitrogen source supplement, while stimulating the synthesis of crop endogenous hormones (such as auxin and cytokinin) to promote root development and cell division; alginate oligosaccharides act as signal molecules to activate receptor proteins on crop cell membranes, enhance cell membrane permeability, and promote the absorption efficiency of mineral elements (such as nitrogen, phosphorus, potassium and trace elements); alginate oligosaccharides can also chelate metal ions to prevent nutrient precipitation. After alginate oligosaccharides increase root vitality, silkworm pupa protein is more easily absorbed and utilized, forming a dual gain mechanism of "nutrition + absorption promotion" and reducing fertilizer waste. Silkworm pupa protein can help crops maintain cell osmotic balance under drought, salinity and other stresses, induce crops to synthesize antioxidant enzymes (such as SOD, POD), and alleviate oxidative damage; alginate oligosaccharides can activate the systemic resistance (SAR) of crops, induce the expression of disease resistance-related genes (such as PR proteins), enhance resistance to fungal and bacterial diseases, regulate the opening and closing of stomata, and reduce water transpiration; silkworm pupa protein enhances crop tolerance from a physiological level, and alginate oligosaccharides activate defense mechanisms from a molecular level. The superposition of the two can significantly improve the adaptability of crops to adversities such as drought, salt damage, and diseases. As a prebiotic, alginate oligosaccharides promote the proliferation of beneficial microorganisms in the rhizosphere (such as nitrogen-fixing bacteria and phosphate-solubilizing bacteria) and inhibit the growth of pathogens; its viscosity can also improve the soil aggregate structure and alleviate compaction; the organic nitrogen and carbon source released after the decomposition of silkworm pupa protein provide nutrition for microorganisms and further promote the activity of microbial communities; the two jointly build a benign rhizosphere microecology, forming a "plant-microorganism" mutually beneficial network, improving soil health in the long term, and reducing soil-borne diseases. Alginate oligosaccharides combine with metal ions to reduce the fixation of elements such as phosphorus and iron, and improve nutrient effectiveness; silkworm pupa protein gradually degrades into small molecule amino acids, extending the nitrogen release cycle; the combined effect of the two can also reduce the loss of fertilizers caused by leaching or volatilization, reduce the pollution of the environment caused by excessive fertilization, and meet the needs of green agriculture.

[0014] Furthermore, the water-soluble fertilizer containing silkworm pupa protein is composed of the following components in terms of mass percentage: 15-20% silkworm pupa protein, 1-2% alginate oligosaccharide, 0.8-1.0% magnesium sulfate, 6-7% potassium dihydrogen phosphate, 5-8% ammonium dihydrogen phosphate, 1-1.1% gelatinized corn flour, 0.05-0.08% polyaspartic acid, and the balance is water.

[0015] Furthermore, the water-soluble fertilizer containing silkworm pupa protein is composed of the following components in terms of mass percentage: 18% silkworm pupa protein, 2% alginate oligosaccharide, 0.9% magnesium sulfate, 7% potassium dihydrogen phosphate, 8% ammonium dihydrogen phosphate, 1.1% gelatinized corn flour, 0.08% polyaspartic acid, and the balance is water.

[0016] Furthermore, the molecular weight of the silkworm pupa protein is 3000-5000Da (3-5kDa). Small molecule silkworm pupa protein is more easily absorbed by roots or leaves, providing a quick-acting nitrogen source, reducing the loss of inorganic nitrogen, promoting plant metabolic enzyme activity, and enhancing photosynthesis and protein synthesis.

[0017] Furthermore, the preparation method of the silkworm pupa protein is: mix silkworm pupa powder and deionized water in a mass ratio of 1:5, adjust the pH to 6.8-7.1, add composite protease, hydrolyze at 40-60°C for 2-4 hours, inactivate the enzyme and then ultrafilter (molecular weight cutoff is 3000-5000Da), and the hydrolysis product is the silkworm pupa protein.

[0018] Furthermore, the composite protease is a mixture of neutral protease and trypsin, wherein the mass ratio of the neutral protease to trypsin is 3:1.

[0019] Furthermore, the gelatinization degree of the gelatinized corn flour is 85-95%, and the viscosity at 25° C. is 200-500 mPa·s.

[0020] Furthermore, the molecular weight of the alginate oligosaccharide is 2000-3000Da.

[0021] The second technical solution of the present invention:

[0022] The present invention provides a method for preparing the water-soluble fertilizer containing silkworm pupa protein, comprising the following steps: accurately weighing each component according to mass percentage, and uniformly mixing each component to obtain the water-soluble fertilizer containing silkworm pupa protein.

[0023] The third technical solution of the present invention:

[0024] The present invention also provides application of the water-soluble fertilizer containing silkworm pupa protein in planting leafy vegetable crops, melon and fruit crops, berry crops and stone fruit crops.

[0025] The water-soluble fertilizer containing silkworm pupa protein can be sprayed on the leaf surface, or can be applied with water irrigation. For example, the application method of the water-soluble fertilizer containing silkworm pupa protein is as follows: dilute the foliar fertilizer containing protein polypeptide by 200-300 times with water, and spray the leaves at an application rate of 300-400g / mu for 1-3 times during the crop growth period.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] The present invention innovatively combines silkworm pupa protein, alginate oligosaccharide and polyaspartic acid in a ternary synergistic compound, achieving a technical breakthrough of "soil improvement - stress resistance enhancement - quality optimization" in water-soluble fertilizers. The specific effects are as follows:

[0028] 1. Restoration of soil micro-ecological system

[0029] Reduce the risk of soil degradation: Silkworm pupa protein (3-5kDa), as a natural organic nitrogen source, can significantly reduce nitrate accumulation and soil acidification, reduce soil bulk density, and effectively alleviate the problem of compaction.

[0030] Activate the microbial network: Silkworm pupa protein provides highly active carbon and nitrogen sources for probiotics such as nitrogen-fixing bacteria and phosphate-solubilizing bacteria. Combined with the regulatory effect of alginate oligosaccharides on microbial quorum sensing, it increases the abundance of rhizosphere probiotics and soil enzyme activity (such as urease and phosphatase).

[0031] Structural improvement and organic matter enhancement: Polyaspartic acid promotes the aggregation of soil particles through electrostatic adsorption, forming a stable particle size aggregate structure. Combined with the polysaccharide adhesive substances produced by microbial metabolism, it increases the soil organic matter content and also improves the soil's water holding capacity.

[0032] 2. Multi-dimensional strengthening of crop stress resistance

[0033] Improved biological disease resistance: Alginate oligosaccharides (molecular weight 2000-3000Da) activate the MAPK signaling pathway, inducing plants to synthesize β-1,3-glucanase and other pathogenesis-related proteins, thereby improving the prevention effect of crops.

[0034] Breakthrough in adaptability to salt-alkali stress: Silkworm pupa protein reduces Na in plant cells under salt stress by enhancing the stability of cell membrane lipid layer + / K + The carboxyl network of polyaspartic acid can adsorb free Na + , increasing crop biomass.

[0035] Synergistic effect of drought resistance and water conservation: The hydrogel structure formed by polyaspartic acid can prolong the effective water content of the soil, and combined with silkworm pupa protein, it promotes root growth and improves the survival rate of crops under drought conditions.

[0036] 3. Synergistic improvement of crop quality and yield

[0037] Nutritional enhancement and flavor optimization: Silkworm pupa protein increases the protein content of the fruit, while alginate oligosaccharides promote the accumulation of phenolic and flavonoid secondary metabolites, thereby optimizing the flavor of the fruit.

[0038] Double benefits of increased production and fertilizer saving: the three-element synergistic system improves nitrogen utilization efficiency.

[0039] 4. Environmental protection and economic advantages

[0040] Green production process: Silkworm pupa protein is extracted using low-temperature enzymatic hydrolysis technology to avoid activity loss caused by high temperature; polyaspartic acid and alginate oligosaccharides are directly compounded in the presence of gelatinized corn flour without the need to add additional stabilizers. Gelatinized corn flour can be used as a slow-release carrier for fertilizers, avoiding fertilizer leaching and reducing production energy consumption.

[0041] Cost advantage of large-scale application: Through the synergistic reduction effect of silkworm pupa protein, alginate oligosaccharides and polyaspartic acid, the amount of fertilizer applied is reduced, making it suitable for large-scale application on field crops. DETAILED DESCRIPTION

[0042] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0043] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0044] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0045] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0046] The embodiment of the present invention provides a water-soluble fertilizer containing silkworm pupa protein, which is composed of the following components according to mass percentage: 10-25% silkworm pupa protein, 1-3% alginate oligosaccharide, 0.6-1.2% magnesium sulfate, 6-8% potassium dihydrogen phosphate, 5-10% ammonium dihydrogen phosphate, 1-1.2% gelatinized corn flour, 0.05-0.1% polyaspartic acid, and the balance is water. Preferably, the water-soluble fertilizer containing silkworm pupa protein is composed of the following components according to mass percentage: 15-20% silkworm pupa protein, 1-2% alginate oligosaccharide, 0.8-1.0% magnesium sulfate, 6-7% potassium dihydrogen phosphate, 5-8% ammonium dihydrogen phosphate, 1-1.1% gelatinized corn flour, 0.05-0.08% polyaspartic acid, and the balance is water. Exemplarily, the water-soluble fertilizer containing silkworm pupa protein is composed of the following components in terms of mass percentage: 18% silkworm pupa protein, 2% alginate oligosaccharide, 0.9% magnesium sulfate, 7% potassium dihydrogen phosphate, 8% ammonium dihydrogen phosphate, 1.1% gelatinized corn flour, 0.08% polyaspartic acid, and the remainder is water.

[0047] Alginate oligosaccharides (AOS) are oligomers degraded from sodium alginate, and are composed of mannuronic acid, guluronic acid or a hybrid segment of the two. Yan Guiling et al. found that adding 2000 mg / kg of alginate oligosaccharides to the diet can increase the daily weight gain of 0-21d broilers, and has a trend of reducing the feed-to-weight ratio. At present, alginate oligosaccharides are mainly used in the field of feed, and are not widely used in the field of fertilizers. The reason may be that the degradation and utilization efficiency of alginate oligosaccharides in the soil are greatly affected by the soil environment. For example, factors such as soil pH and microbial activity can affect the performance of its biological activity. In addition, if used improperly, it may have a negative impact on the soil ecosystem. In order to avoid the above problems, the present invention combines alginate oligosaccharides with silkworm pupa protein and polyaspartic acid, which can effectively avoid the problem that alginate oligosaccharides are greatly affected by the soil environment.

[0048] Silkworm pupa protein can be directly absorbed by crop roots or leaves as a nitrogen source supplement, while stimulating the synthesis of crop endogenous hormones (such as auxin and cytokinin) to promote root development and cell division; alginate oligosaccharides act as signal molecules to activate receptor proteins on crop cell membranes, enhance cell membrane permeability, and promote the absorption efficiency of mineral elements (such as nitrogen, phosphorus, potassium and trace elements); alginate oligosaccharides can also chelate metal ions to prevent nutrient precipitation. After alginate oligosaccharides increase root vitality, silkworm pupa protein is more easily absorbed and utilized, forming a double gain of "nutrition + absorption promotion" and reducing fertilizer waste. Silkworm pupa protein can help crops maintain cell osmotic balance under drought, salinity and other stresses, induce crops to synthesize antioxidant enzymes (such as SOD, POD), and alleviate oxidative damage; alginate oligosaccharides can activate the systemic resistance (SAR) of crops, induce the expression of disease resistance-related genes (such as PR proteins), enhance resistance to fungal and bacterial diseases, regulate the opening and closing of stomata, and reduce water transpiration; silkworm pupa protein enhances crop tolerance from a physiological level, and alginate oligosaccharides activate defense mechanisms from a molecular level. The superposition of the two can significantly improve the adaptability of crops to adversities such as drought, salt damage, and diseases. As a prebiotic, alginate oligosaccharides promote the proliferation of beneficial microorganisms in the rhizosphere (such as nitrogen-fixing bacteria and phosphate-solubilizing bacteria) and inhibit the growth of pathogens; its viscosity can also improve the soil aggregate structure and alleviate compaction; the organic nitrogen and carbon source released after the decomposition of silkworm pupa protein provide nutrition for microorganisms and further promote the activity of microbial communities; the two jointly build a benign rhizosphere microecology, forming a "plant-microorganism" mutually beneficial network, improving soil health in the long term, and reducing soil-borne diseases. Alginate oligosaccharides bind to metal ions, reducing the fixation of elements such as phosphorus and iron, and improving nutrient effectiveness; silkworm pupa protein is gradually degraded into small molecular amino acids, extending the nitrogen release cycle; the combined effect of the two can also reduce the loss of fertilizers caused by leaching or volatilization, reduce the pollution of the environment caused by excessive fertilization, and meet the needs of green agriculture. Alginate oligosaccharides act as signal molecules to activate plant cell membrane transport proteins (such as H + -ATPase), enhance ion channel activity, and promote transmembrane transport of amino acids and trace elements in silkworm pupa protein. Polyaspartic acid stabilizes metal ions (such as Fe 2+ 、Zn 2+ ), prolonging the nutrient release cycle, and enhancing the root system's ability to adsorb silkworm pupa protein small molecule peptides. The combination of the three can achieve "fast-acting + slow-release" dual-mode fertilization and reduce leaching losses.

[0049] In the embodiment of the present invention, the molecular weight of silkworm pupa protein is 3000-5000Da. Small molecule silkworm pupa protein is more easily absorbed by roots or leaves, providing a quick-acting nitrogen source, reducing the loss of inorganic nitrogen, promoting plant metabolic enzyme activity, and enhancing photosynthesis and protein synthesis.

[0050] In an embodiment of the present invention, the preparation method of silkworm pupa protein is: mix silkworm pupa powder and deionized water in a mass ratio of 1:5, adjust the pH to 6.8-7.1, add composite protease, hydrolyze at 40-60°C for 2-4 hours, inactivate the enzyme and then ultrafilter (molecular weight cutoff is 3000-5000Da), and the hydrolysis product is silkworm pupa protein.

[0051] In an embodiment of the present invention, the composite protease is a mixture of neutral protease and trypsin, and the mass ratio of neutral protease to trypsin is 3:1.

[0052] In an embodiment of the present invention, the gelatinization degree of the gelatinized corn flour is 85-95%, and the viscosity at 25° C. is 200-500 mPa·s.

[0053] In an embodiment of the present invention, the preparation method of gelatinized corn flour is: mix corn flour and water in a mass ratio of 1:3, stir and gelatinize at 90°C for 20-50 minutes, and spray dry after cooling (the inlet air temperature is 75°C and the atomization pressure is 0.3MPa).

[0054] In an embodiment of the present invention, the molecular weight of alginate oligosaccharide is 2000-3000 Da.

[0055] In an embodiment of the present invention, the preparation method of alginate oligosaccharides is as follows: sodium alginate is dissolved in PBS buffer solution, alginate lyase (such as Pseudomonas aeruginosa) is added, reacted at 37°C for 6 hours, ultrafiltration (molecular weight cutoff is 2000-3000Da) after enzyme inactivation, and alginate oligosaccharides are obtained after freeze-drying.

[0056] In an embodiment of the present invention, a method for preparing the above-mentioned water-soluble fertilizer containing silkworm pupa protein is also provided, comprising the following steps: accurately weighing each component according to the mass percentage, mixing each component evenly, and obtaining the water-soluble fertilizer containing silkworm pupa protein.

[0057] The water-soluble fertilizer containing silkworm pupa protein provided by the embodiment of the present invention can be used in the planting of leafy vegetables, melon and fruit crops, berry crops and stone fruit crops.

[0058] Preferably, the leafy vegetable crops are lettuce and cabbage; the melon and fruit crops are cucumbers; the berry crops are grapes; and the stone fruit crops are cherries.

[0059] The water-soluble fertilizer containing silkworm pupa protein can be sprayed on the leaf surface, or can be applied with water irrigation. For example, the application method of the water-soluble fertilizer containing silkworm pupa protein is as follows: dilute the foliar fertilizer containing protein polypeptide by 200-300 times with water, and spray the leaves at an application rate of 300-400g / mu for 1-3 times during the crop growth period.

[0060] Unless otherwise specified, the room temperature in the present invention is 25±2°C.

[0061] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0062] It should be pointed out that the matters not described in detail in the present invention are all conventional operating means in the art and are not the focus of the present invention. For example, specific methods such as spray drying and freeze drying are all carried out using conventional methods.

[0063] The technical solution of the present invention is further illustrated by the following embodiments.

[0064] Example 1

[0065] The present embodiment provides a water-soluble fertilizer containing silkworm pupa protein, which is composed of the following components in terms of mass percentage: 18% silkworm pupa protein, 2% alginate oligosaccharide, 0.9% magnesium sulfate, 7% potassium dihydrogen phosphate, 8% ammonium dihydrogen phosphate, 1.1% gelatinized corn flour, 0.08% polyaspartic acid, and the balance is water;

[0066] The preparation method of silkworm pupa protein is as follows: silkworm pupa powder and deionized water are mixed in a mass ratio of 1:5, the pH is adjusted to 7, a composite protease (neutral protease and trypsin in a mass ratio of 3:1) is added, hydrolyzed at 50°C for 3 hours, and ultrafiltration (molecular weight cutoff is 4000Da) is performed after the enzyme is inactivated, and the hydrolysis product is silkworm pupa protein with a molecular weight of 4000Da;

[0067] The preparation method of gelatinized corn flour is as follows: corn flour and water are mixed in a mass ratio of 1:3, stirred and gelatinized at 90°C for 30 minutes, and spray-dried (the air inlet temperature is 75°C and the atomization pressure is 0.3MPa) after cooling, and the gelatinization degree of the gelatinized corn flour is 90%, and the viscosity at 25°C is 400mPa·s;

[0068] The preparation method of alginate oligosaccharide is as follows: sodium alginate is dissolved in PBS buffer solution, Pseudomonas aeruginosa is added, reacted at 37°C for 6 hours, ultrafiltered (molecular weight cutoff is 2000Da) after enzyme inactivation, and freeze-dried to obtain alginate oligosaccharide;

[0069] The preparation method of the water-soluble fertilizer containing silkworm pupa protein is as follows: accurately weighing each component according to the mass percentage, and mixing each component evenly to obtain the water-soluble fertilizer containing silkworm pupa protein.

[0070] Example 2

[0071] The present embodiment provides a water-soluble fertilizer containing silkworm pupa protein, which is composed of the following components in terms of mass percentage: 15% silkworm pupa protein, 2% alginate oligosaccharide, 0.8% magnesium sulfate, 6% potassium dihydrogen phosphate, 5% ammonium dihydrogen phosphate, 1% gelatinized corn flour, 0.05% polyaspartic acid, and the balance is water;

[0072] The preparation method of silkworm pupa protein is as follows: silkworm pupa powder and deionized water are mixed in a mass ratio of 1:5, the pH is adjusted to 6.8, a composite protease (neutral protease and trypsin in a mass ratio of 3:1) is added, hydrolyzed at 60°C for 2 hours, and ultrafiltration (molecular weight cutoff of 3000Da) is performed after the enzyme is inactivated, and the hydrolysis product is silkworm pupa protein with a molecular weight of 3000Da;

[0073] The preparation method of gelatinized corn flour is as follows: corn flour and water are mixed in a mass ratio of 1:3, stirred and gelatinized at 90°C for 20 minutes, and spray-dried (the inlet air temperature is 75°C and the atomization pressure is 0.3MPa) after cooling, and the gelatinization degree of the gelatinized corn flour is 85%, and the viscosity at 25°C is 340mPa·s;

[0074] The preparation method of alginate oligosaccharide is as follows: sodium alginate is dissolved in PBS buffer solution, Pseudomonas aeruginosa is added, reacted at 37°C for 6 hours, ultrafiltered (molecular weight cutoff is 3000Da) after enzyme inactivation, and freeze-dried to obtain alginate oligosaccharide;

[0075] The preparation method of the water-soluble fertilizer containing silkworm pupa protein is as follows: accurately weighing each component according to the mass percentage, mixing each component evenly, and obtaining the water-soluble fertilizer containing silkworm pupa protein.

[0076] Example 3

[0077] The present embodiment provides a water-soluble fertilizer containing silkworm pupa protein, which is composed of the following components in terms of mass percentage: 25% silkworm pupa protein, 1% alginate oligosaccharide, 1.2% magnesium sulfate, 8% potassium dihydrogen phosphate, 10% ammonium dihydrogen phosphate, 1.2% gelatinized corn flour, 0.1% polyaspartic acid, and the balance is water;

[0078] The preparation method of silkworm pupa protein, gelatinized corn flour and alginate oligosaccharide is the same as that of Example 1;

[0079] The preparation method of the water-soluble fertilizer containing silkworm pupa protein is the same as that in Example 1.

[0080] Comparative Example 1

[0081] This comparative example provides a water-soluble fertilizer containing silkworm pupa protein. The components and preparation method are the same as those in Example 1, except that alginate oligosaccharides are not added.

[0082] Comparative Example 2

[0083] This comparative example provides a water-soluble fertilizer, and the components and preparation method are the same as those in Example 1, except that no silkworm pupa protein is added.

[0084] Comparative Example 3

[0085] This comparative example provides a water-soluble fertilizer containing silkworm pupa protein. The components and preparation method are the same as those in Example 1, except that polyaspartic acid is not added.

[0086] Comparative Example 4

[0087] This comparative example provides a water-soluble fertilizer containing silkworm pupa protein. The components and preparation method are the same as those in Example 1, except that gelatinized corn flour is not added.

[0088] Application Example 1

[0089] Cherries were treated with the water-soluble fertilizers in Examples 1-3 and Comparative Examples 1-4. The specific treatment method is as follows: the test cherries were 6-year-old Shamir cherries, which were divided into 8 treatments. The water-soluble fertilizers obtained in Examples 1-3 and Comparative Examples 1-4 were diluted 300 times, respectively, and clean water was used as a control. They were sprayed twice on May 5 and May 20, respectively, and harvested on May 30.

[0090] After harvesting, the soluble solid content of cherry fruit was determined by refractometer, the weight of single fruit was measured by electronic balance, and the coloring was measured by visual inspection (expressed as coloring degree), where the coloring degree standards are as follows: Grade 1: the fruit is all purple-red; Grade 2: the fruit is all bright red or has purple-red; Grade 3: light red or has bright red; Grade 4: the fruit surface is not completely light red, and part of the fruit surface is yellow-green. The results are shown in Table 1.

[0091] Table 1

[0092]

[0093] As can be seen from the data in Table 1, among Examples 1-3, the combination of silkworm pupa protein + alginate oligosaccharide + polyaspartic acid in Example 1 performs best: Soluble solids: Example 1 is 37% higher than the control group (18.5% vs 13.5%), 21% higher than Comparative Example 1 (without alginate oligosaccharide), and 15% higher than Comparative Example 3 (without polyaspartic acid). Single fruit weight: Example 1 is 30.6% higher than Comparative Example 2 (without silkworm pupa protein) (12.8g vs 9.8g). Coloring degree: Example 1 is the most uniformly colored (1.2 grades), which is 53.8% better than Comparative Example 1 (without alginate oligosaccharide). Absence of alginate oligosaccharide (Comparative Example 1): Nutrient absorption is blocked, soluble solids and single fruit weight are significantly reduced, and coloring is uneven (absorption-promoting and stress-resistant functions of alginate oligosaccharide are missing). Absence of silkworm pupa protein (Comparative Example 2): Insufficient amino acids and osmotic regulating substances, fruit development is restricted, and single fruit weight is the lowest. Lack of polyaspartic acid (Comparative Example 3): The metal ion chelating ability is reduced, the nutrient utilization rate is reduced, and the soluble solid content is reduced. Lack of gelatinized corn flour (Comparative Example 4): The fertilizer viscosity is insufficient and the leaf surface adhesion is poor, resulting in a reduced absorption rate of the effective ingredients. Through the ternary synergy of silkworm pupa protein, alginate oligosaccharides and polyaspartic acid, polyaspartic acid chelates nutrients, alginate oligosaccharides promote microbial proliferation, silkworm pupa protein enhances osmotic regulation, and alginate oligosaccharides activate defense genes. The three synergistically improve the accumulation of photosynthetic products (soluble solids) and fruit enlargement (single fruit weight), and promote anthocyanin synthesis (coloring optimization).

[0094] Application Example 2

[0095] Grapes were treated with the water-soluble fertilizers in Examples 1-3 and Comparative Examples 1-4. The specific treatment method is as follows: The test grapes were 3-year-old Marsland grapes. The test was divided into six treatments. The water-soluble fertilizers obtained in Examples 1-3 and Comparative Examples 1-4 were diluted 300 times, respectively, and clean water was used as a control. The grapes were sprayed once on August 15 and harvested on September 10. After harvesting, the soluble solid content of cherry fruits was measured with a refractometer, and the weight of a single fruit was measured with an electronic balance. The results are shown in Table 2.

[0096] Table 2

[0097] Fruit soluble solid content (%) Single fruit weight (g) Example 1 21.6±0.4 14.2±0.2 Example 2 20.8±0.3 13.5±0.1 Example 3 19.7±0.5 12.8±0.2 Comparative Example 1 18.2±0.6 11.3±0.5 Comparative Example 2 17.5±0.4 10.6±0.3 Comparative Example 3 19.0±0.2 12.1±0.4 Comparative Example 4 18.8±0.3 11.8±0.2 Control group 16.3±0.5 9.2±0.4

[0098] As can be seen from the data in Table 2, the water-soluble fertilizer of Example 1 has the best effect: the soluble solid content is 32.5% higher than that of the control group (21.6% vs 16.3%), and the single fruit weight is 54.3% higher (14.2g vs 9.2g). The soluble solid content of the fruit of the comparative example 1 (without alginate oligosaccharide) water-soluble fertilizer is significantly reduced (18.2%), indicating that the promoting effect of alginate oligosaccharide on sugar accumulation is irreplaceable. The single fruit weight of the fruit of the comparative example 2 (without silkworm pupa protein) water-soluble fertilizer is the lowest (10.6g), indicating the key role of silkworm pupa protein in fruit enlargement. The soluble solid content (19.0%) of the fruit of the comparative example 3 (without polyaspartic acid) water-soluble fertilizer is slightly higher than that of the comparative example 1 (18.2%), but significantly lower than that of the embodiment 1 (21.6%), indicating that polyaspartic acid indirectly supports sugar synthesis by chelating nutrients. The single fruit weight (11.8 g) of the fruit treated with the water-soluble fertilizer of Comparative Example 4 (no gelatinized corn flour) was slightly higher than that of Comparative Example 1 (11.3 g), but lower than that of Example 1 (14.2 g), indicating that gelatinized corn flour enhances fertilizer efficiency by increasing leaf adhesion, but its effect is weaker than that of the core ternary components.

[0099] Application Example 3

[0100] The water-soluble fertilizers prepared in Example 1-3 and Comparative Example 1-3 were diluted 300 times with water and sprayed once on the leaves of lettuce at the seedling stage at an application rate of 400 g per mu. The appearance and yield of the lettuce are shown in Table 3.

[0101] Table 3

[0102] Lettuce Appearance Yield (kg / mu) Example 1 Green leaves, vigorous growth 3100±15 Example 2 Green leaves, vigorous growth 3050±22 Example 3 Green leaves, vigorous growth 3010±17 Comparative Example 1 Green leaves, good growth 2830±18 Comparative Example 2 The leaves are green and the growth is average. 2710±20 Comparative Example 3 The leaves are green and the growth is average. 2960±53 Control group Light green leaves, slow growth 2500±57

[0103] Application Example 4

[0104] The water-soluble fertilizers prepared in Example 1 and Comparative Examples 1-3 were diluted 200 times with water and sprayed on the leaves of autumn cucumbers at the seedling stage and young cucumber stage at an application rate of 300 g per mu. The cucumber yields are shown in Table 4.

[0105] Table 4

[0106] Yield (kg / mu) Example 1 7520±20 Comparative Example 1 7035±21 Comparative Example 2 6850±30 Comparative Example 3 7120±32 Control group 6500±31

[0107] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A water-soluble fertilizer containing silkworm pupa protein, characterized in that: According to mass percentage, it is composed of the following components: Silkworm pupa protein 10-25%, alginate oligosaccharide 1-3%, magnesium sulfate 0.6-1.2%, potassium dihydrogen phosphate 6-8%, ammonium dihydrogen phosphate 5-10%, gelatinized corn flour 1-1.2%, polyaspartic acid 0.05-0.1%, and the balance is water.

2. The water-soluble fertilizer containing silkworm pupa protein according to claim 1, characterized in that: According to mass percentage, it is composed of the following components: Silkworm pupa protein 15-20%, alginate oligosaccharide 1-2%, magnesium sulfate 0.8-1.0%, potassium dihydrogen phosphate 6-7%, ammonium dihydrogen phosphate 5-8%, gelatinized corn flour 1-1.1%, polyaspartic acid 0.05-0.08%, and the balance is water.

3. The water-soluble fertilizer containing silkworm pupa protein according to claim 2, characterized in that: According to mass percentage, it is composed of the following components: Silkworm pupa protein 18%, alginate oligosaccharide 2%, magnesium sulfate 0.9%, potassium dihydrogen phosphate 7%, ammonium dihydrogen phosphate 8%, gelatinized corn flour 1.1%, polyaspartic acid 0.08%, and the balance is water.

4. The water-soluble fertilizer containing silkworm pupa protein according to claim 3, characterized in that: The molecular weight of the silkworm pupa protein is 3000-5000Da.

5. The water-soluble fertilizer containing silkworm pupa protein according to claim 3, characterized in that: The preparation method of the silkworm pupa protein is as follows: silkworm pupa powder and deionized water are mixed at a mass ratio of 1:5, the pH is adjusted to 6.8-7.1, a composite protease is added, hydrolyzed at 40-60° C. for 2-4 hours, the enzyme is inactivated and then ultrafiltered, and the hydrolysis product is the silkworm pupa protein.

6. The water-soluble fertilizer containing silkworm pupa protein according to claim 5, characterized in that: The composite protease is a mixture of neutral protease and trypsin, wherein the mass ratio of the neutral protease to the trypsin is 3:

1.

7. The water-soluble fertilizer containing silkworm pupa protein according to claim 3, characterized in that: The gelatinization degree of the gelatinized corn flour is 85-95%, and the viscosity at 25° C. is 200-500 mPa·s.

8. The water-soluble fertilizer containing silkworm pupa protein according to claim 3, characterized in that: The molecular weight of the alginate oligosaccharide is 2000-3000Da.

9. A method for preparing the water-soluble fertilizer containing silkworm pupa protein according to any one of claims 1 to 8, characterized in that: The following steps are involved: The components are accurately weighed according to the mass percentage, and the components are evenly mixed to obtain the water-soluble fertilizer containing silkworm pupa protein.

10. Use of the water-soluble fertilizer containing silkworm pupa protein according to any one of claims 1 to 8 in the planting of leafy vegetables, melons and fruits, berry crops and stone fruit crops.

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