Special fertilizer for disease-resistant crops and preparation method thereof

Abstract

The invention relates to the field of fertilizers, in particular to a special fertilizer for disease-resistant crops and a preparation method thereof.The special fertilizer comprises a nutrient core, a microbial agent coating and a medium trace element coating from inside to outside; the nutrient core comprises the following components in parts by weight: 35-40 parts of a nitrogen fertilizer, 20-25 parts of a phosphate fertilizer, 15-20 parts of a potassium fertilizer, 3-5 parts of a synergist and 1-1.5 parts of molasses; the microbial agent coating layer comprises 1-2 parts of a liquid microbial solution, 1-2 parts of a microbial protective agent and 3-5 parts of a microbial agent carrier; the medium trace element coating layer comprises 5-10 parts of a medium trace element fertilizer and 0.8-1.6 parts of a coating agent. According to the disease-resistant crop special fertilizer provided by the invention, the medium trace elements are added in an external wrapping manner, so that the condition that the effectiveness of nutritional ingredients is reduced due to chemical reaction between metal cations of the medium trace elements and phosphate ions in a phosphate fertilizer in a fertilizer production process is avoided.

Description

Technical Field

[0001] The present invention relates to the field of fertilizers, and particularly to a special fertilizer for disease-resistant crops and a preparation method thereof. Background Art

[0002] Diseases caused by pathogenic microorganisms such as bacteria, fungi, and pests seriously affect the yield and quality of crops. According to statistics, the annual reduction in grain production caused by pathogenic microorganisms exceeds 20%, posing a huge threat to food security. Currently, the main way to control pathogenic microorganisms is by using chemical pesticides. However, long-term application of chemical pesticides not only increases the resistance of pathogenic microorganisms and reduces the efficacy of pesticides, but also causes problems such as environmental pollution.

[0003] Microbial inoculants are green, environmentally friendly, and low-cost. They can improve the soil, improve the microenvironment of crop roots, and enhance the disease resistance of crops, and are widely used in modern agricultural production. In planting, microbial inoculants are often applied in combination with fertilizers, but this will increase labor costs. Therefore, it is of great significance to develop compound products of fertilizers and microbial inoculants. However, in the fertilizer production process such as tower granulation and spray granulation, relatively high temperatures often occur, which easily causes a decrease in the number of active bacteria and affects the final application effect.

[0004] High-intensity planting activities will take away a large amount of nutrients from the soil. Among them, macronutrients such as nitrogen, phosphorus, and potassium can be supplemented by fertilization, while the application of medium and micronutrient fertilizers is relatively insufficient. Medium and micronutrient fertilizers can improve the quality of agricultural crops, enhance the disease resistance of crops, and also improve the soil structure. Their deficiency not only leads to "nutrient deficiency symptoms" in crops, but also affects the absorption of macronutrients by plants, resulting in low fertilizer utilization efficiency. Currently, fertilizer enterprises add medium and micronutrients to traditional compound fertilizers to make new fertilizers. However, medium and micronutrients are mainly divalent metal ions, and active ions such as phosphate groups in phosphate fertilizers are prone to chemical reactions with divalent cations under certain conditions to form precipitates, thereby affecting the field application effect of medium and micronutrients. Therefore, there is an urgent need to develop a compound fertilizer and production method that can efficiently utilize medium and micronutrients. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a special fertilizer for disease-resistant crops and a preparation method thereof.

[0006] The purpose of the present invention is achieved by the following technical solutions:

[0007] In a first aspect, the present invention provides a special fertilizer for disease-resistant crops. The fertilizer is granular and includes a nutrient core, a microbial inoculant coating, and a medium and trace element coating from the inside out. By weight, the nutrient core includes 35-40 parts of nitrogen fertilizer, 20-25 parts of phosphate fertilizer, 15-20 parts of potassium fertilizer, 3-5 parts of synergist, and 1-1.5 parts of molasses; the microbial inoculant coating layer includes 1-2 parts of liquid microbial inoculant, 1-2 parts of microbial protectant, and 3-5 parts of microbial inoculant carrier; the medium and trace element coating layer includes 5-10 parts of medium and trace element fertilizer and 0.8-1.6 parts of wrapping agent.

[0008] Preferably, the nitrogen fertilizer is one or more of urea, ammonium bicarbonate, ammonium sulfate, ammonium chloride, sodium nitrate, calcium nitrate, ammonium nitrate.

[0009] Preferably, the phosphate fertilizer is one or more of monoammonium phosphate, diammonium phosphate, ammonium phosphate, polyphosphate ammonium, superphosphate, triple superphosphate, calcium magnesium phosphate fertilizer, phosphate rock powder.

[0010] Preferably, the potassium fertilizer is one or more of potassium chloride, potassium sulfate.

[0011] Preferably, the synergist is one or more of humic acid, alginic acid, chitosan, amino acid.

[0012] Preferably, the medium and trace element fertilizer is one or more of compounds of calcium, magnesium, iron, copper, zinc, manganese, molybdenum.

[0013] Preferably, the liquid microbial inoculant is composed of Bacillus subtilis, Bacillus mucilaginosus, and Pseudomonas fluorescens, wherein the effective viable count of Bacillus subtilis is not less than 200 million / mL, the effective viable count of Bacillus mucilaginosus is not less than 200 million / mL, and the effective viable count of Pseudomonas fluorescens is not less than 500 million / mL.

[0014] Preferably, the microbial protectant is a mixture of fucoidan oligosaccharide and rhamnolipid.

[0015] Preferably, the mass ratio of fucoidan oligosaccharide to rhamnolipid in the microbial protectant is 1:(1-1.5).

[0016] Preferably, the average degree of polymerization of fucoidan oligosaccharide in the microbial protectant is not higher than 5.

[0017] Preferably, the preparation method of the microbial inoculant carrier includes:

[0018] S1. Aging treatment:

[0019] After grinding diatomite and screening it through a 150-180 mesh sieve, add it to a 1mol / L sulfuric acid solution, stir and react for 1.5-2h, then wash it with water until the filtrate is neutral, and then dry it at 105°C to obtain the aged diatomite;

[0020] S2. Introduce metal ions:

[0021] Add manganese sulfate and iron sulfate into deionized water to form a sulfate solution; add the aged diatomite, and mix well until uniform to obtain a diatomite mixture;

[0022] S3. Modification treatment:

[0023] Add humic acid (50 kDa - 100 kDa) into a sodium hydroxide solution with pH = 8 - 9, stir until completely dissolved to obtain a humic acid solution; dropwise add the humic acid solution into the diatomite mixture, continuously stir during the dropping process, after the dropping is completed, adjust the pH of the system to 4 - 6, stand for 10 - 20 h, dry under reduced pressure, wash with distilled water 3 - 5 times, and dry at 105 °C to obtain a microbial inoculum carrier.

[0024] Preferably, in S1, the mass - volume ratio of diatomite to sulfuric acid solution is 1 g:(10 - 20) mL.

[0025] Preferably, in S2, the mass - volume ratio of the aged diatomite, manganese sulfate, iron sulfate and deionized water is 1 g:(0.13 - 0.18) g:(0.2 - 0.4) g:(10 - 20) mL.

[0026] Preferably, in S3, the mass - volume ratio of humic acid to sodium hydroxide solution is 1 g:(5 - 10) mL; the volume ratio of the humic acid solution to the diatomite mixture is 1:3 - 6.

[0027] Preferably, the coating agent is modified arabic gum, and the preparation method includes:

[0028] S10. Prepare phosphorylated chitosan:

[0029] Weigh chitosan and dissolve it in an acetic acid solution, dropwise add phosphoric acid solution, heat up to 50 - 60 °C, stir for 10 - 15 h, after the treatment is completed, pour it into ethanol, collect the precipitate, wash with ethanol 3 times, and dry at 60 °C to obtain phosphorylated chitosan;

[0030] S11. Prepare raw materials:

[0031] Dissolve phosphorylated chitosan in distilled water to make a phosphorylated chitosan solution; dissolve arabic gum in a sodium hydroxide solution first, heat the solution to 50 °C, and then dilute it with distilled water to make an arabic gum solution;

[0032] S12. Prepare modified arabic gum:

[0033] Slowly add the phosphorylated chitosan solution to the gum arabic solution, stir at a speed of 600 rpm at 50 - 60 °C for 2 - 4 h, then adjust the pH of the system to 5 - 6, filter and wash with distilled water 3 - 5 times, and dry at 60 °C to obtain the modified gum arabic.

[0034] Preferably, in the S10, the mass fraction of the acetic acid solution is 2% - 4%, and the mass - to - volume ratio of chitosan to the acetic acid solution is 1 g:(10 - 20) mL.

[0035] Preferably, in the S10, the mass fraction of the phosphoric acid solution is 80% - 85%, and the addition amount of the phosphoric acid solution is 1:4 - 6 of the volume of the acetic acid solution.

[0036] Preferably, in the S11, the mass fraction of phosphorylated chitosan in the phosphorylated chitosan solution is 1 - 3%; the mass fraction of the sodium hydroxide solution is 0.5 - 2.5%; the mass fraction of gum arabic in the gum arabic solution is 2 - 4%.

[0037] Preferably, in the S12, the volume ratio of the phosphorylated chitosan solution to the gum arabic solution is 1:2 - 3.

[0038] In the second aspect, the present invention provides a preparation method of a special fertilizer for disease - resistant crops, and the steps include:

[0039] Step 1, prepare nutrient cores: Weigh nitrogen fertilizer, phosphate fertilizer, potassium fertilizer and synergist according to the weight ratio, mix them evenly and granulate them into fertilizer particles, place the fertilizer particles in a constant - temperature drying oven at 40 - 42 °C for 2 h, then add them to a coating device, and spray - coat molasses on the surface of the nutrient cores to obtain nutrient cores;

[0040] Step 2, cover with a microbial inoculant coating: Add a microbial protectant and a microbial inoculant carrier to the liquid microbial inoculant, fully shake and contact for 10 - 15 min, filter and collect the solid, and freeze - dry to obtain a microbial inoculant coating material. Subsequently, spray - coat the microbial inoculant coating material on the surface of the nutrient cores to obtain nutrient cores covered with a microbial inoculant coating;

[0041] Step 3, cover with a coating of medium and trace elements: Heat the nutrient cores covered with a microbial inoculant coating to 40 - 42 °C, spray - coat a wrapping agent on the nutrient cores covered with a microbial inoculant coating, and then further spray a medium and trace element fertilizer on the surface, and cool and dry to obtain the special fertilizer for disease - resistant crops.

[0042] Preferably, in Step 1, the diameter of the nutrient cores is 2.6 - 2.8 mm; in Step 2, the diameter of the nutrient cores covered with a microbial inoculant coating is 3.0 - 3.2 mm; in Step 3, the diameter of the special fertilizer for disease - resistant crops is 3.5 - 3.7 mm.

[0043] The beneficial effects of the present invention are as follows:

[0044] 1. The disease-resistant crop special fertilizer provided by the present invention has a multi-layer coating structure for fertilizer granules. The nutrient core in the innermost layer can slowly release macronutrients and synergists into the soil through the microbial inoculant coating layer and the medium and trace element coating layer, meeting the demand for macronutrients during the growth period of crops; the microbial inoculant coating layer contains beneficial microorganisms that improve the physical and chemical properties of the soil, improve the rhizosphere microenvironment of crops, and enhance the stress resistance of crops, effectively improving the resistance of crops to adverse environments and enhancing the quality of crops; the medium and trace element coating layer can effectively supplement the medium and trace elements lacking in the soil, further enhancing the yield and quality of crops.

[0045] 2. The disease-resistant crop special fertilizer provided by the present invention, the microbial inoculant coating layer includes a microbial protectant and a microbial inoculant carrier. The microbial protectant is composed of alginate oligosaccharide and rhamnolipid, which can effectively reduce the problem of reduced microbial activity caused by adverse environmental factors such as high temperature during the fertilizer production process. The microbial inoculant carrier introduces a complex of humic acid and manganese and iron on the basis of diatomite, which not only has rich micropores and adsorption properties, but also can provide a microenvironment for the efficient reproduction of microorganisms, reducing the impact of adverse environmental factors on microbial activity.

[0046] 3. The disease-resistant crop special fertilizer provided by the present invention adds medium and trace elements in an outer wrapping manner, avoiding the chemical reaction between the metal cations of medium and trace elements and the phosphate ions in phosphate fertilizer during the fertilizer production process, reducing the effectiveness of nutrient components.

[0047] 4. The disease-resistant crop special fertilizer provided by the present invention, the coating agent in the medium and trace element coating layer is modified arabic gum, which is obtained by phosphorylating chitosan and arabic gum through a phosphorylation reaction. The modified arabic gum has stronger adsorption to medium and trace element fertilizers, which can not only supply nutrients gradually during the growth period of crops, improving the nutrient utilization rate of crops, but also further protect the microbial inoculant, avoiding the impact on microbial activity during the storage and transportation of fertilizers. Detailed implementation manners

[0048] The technical solutions of the present invention will be described below through specific specific examples. It should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before and after the combined steps or that other method steps can be inserted between these explicitly mentioned steps; it should also be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. Moreover, unless otherwise specified, the numbers of the method steps are only convenient tools for identifying the method steps, rather than limiting the arrangement order of the method steps or the scope in which the present invention can be implemented. The change or adjustment of their relative relationship, without substantial change in the technical content, should also be regarded as the scope in which the present invention can be implemented.

[0049] To better understand the above technical solutions, the exemplary embodiments of the present invention will be described in more detail below. Although the exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to be able to convey the scope of the present invention completely to those skilled in the art.

[0050] The present invention will be further described below in conjunction with the following embodiments.

[0051] Embodiment 1

[0052] A special fertilizer for disease-resistant crops, the fertilizer is granular, and from the inside out, it includes a nutrient core, a microbial inoculant coating, and a medium and trace element coating; by weight, the nutrient core includes 37 parts of urea, 22 parts of monoammonium phosphate, 18 parts of potassium chloride, 4 parts of humic acid, and 1 part of molasses; the microbial inoculant coating layer includes 1.5 parts of liquid microbial inoculant, 1.5 parts of microbial protectant, and 4 parts of microbial inoculant carrier; the medium and trace element coating layer includes 7 parts of medium and trace element fertilizer and 1.2 parts of coating agent.

[0053] Among them, the liquid microbial inoculant is composed of Bacillus subtilis, Bacillus mucilaginosus, and Pseudomonas fluorescens. The effective viable count of Bacillus subtilis is not less than 200 million / mL, the effective viable count of Bacillus mucilaginosus is not less than 200 million / mL, and the effective viable count of Pseudomonas fluorescens is not less than 500 million / mL.

[0054] Among them, the microbial protectant is a mixture of alginate oligosaccharide (average degree of polymerization is 4) and rhamnolipid in a mass ratio of 1:1.

[0055] Among them, the preparation method of the microbial inoculant carrier includes:

[0056] S1. Grind 1 g of diatomaceous earth and pass it through a 160-mesh sieve, add it to 15 mL of 1 mol / L sulfuric acid solution, stir and react for 2 h, then wash with water until the filtrate is neutral, and then dry at 105 °C to obtain aged diatomaceous earth;

[0057] S2. Add 0.15 g of manganese sulfate and 0.3 g of ferric sulfate into 15 mL of deionized water to form a sulfate solution; add 1 g of aged diatomite, and mix well until uniform to obtain a diatomite mixture.

[0058] S3. Add 1 g of humic acid (80 kDa) into 8 mL of sodium hydroxide solution with pH = 8 - 9, stir until fully dissolved to obtain a humic acid solution; dropwise add the humic acid solution into the diatomite mixture, and the volume ratio of the humic acid solution to the diatomite mixture is 1:4. Stir continuously during the dropping process. After the dropping is completed, adjust the pH of the system to 4 - 6, stand for 15 h, perform vacuum drying, wash 3 times with distilled water, and dry at 105 °C to obtain a microbial inoculant carrier.

[0059] Among them, the medium and trace element fertilizer is composed of magnesium sulfate, ferrous ammonium humate, cupric sulfate monohydrate, zinc sulfate monohydrate, manganese sulfate, and sodium molybdate according to a mass ratio of 1:1:1:1:1:1.

[0060] Among them, the coating agent is modified arabic gum, and the preparation method includes:

[0061] S10. Weigh 1 g of chitosan and dissolve it in 15 mL of 4 wt% acetic acid solution. Dropwise add 85 wt% phosphoric acid solution, and the added amount is 1 / 5 of the volume of the acetic acid solution. Heat to 50 - 60 °C and stir for 12 h. After the treatment is completed, pour it into 2 times the volume of ethanol, collect the precipitate, wash 3 times with ethanol, and dry at 60 °C to obtain phosphorylated chitosan.

[0062] S11. Dissolve phosphorylated chitosan in distilled water to make a phosphorylated chitosan solution with a mass fraction of 2%; first dissolve arabic gum in a 1.5 wt% sodium hydroxide solution, heat the solution to 50 °C, and then dilute it with distilled water to make an arabic gum solution with a mass fraction of 3%.

[0063] S12. Slowly add the phosphorylated chitosan solution into the arabic gum solution. The volume ratio of the arabic gum solution to the phosphorylated chitosan solution is 2.5:1. Stir at a speed of 600 rpm at 55 °C for 3 h, then adjust the pH of the system to 5 - 6, filter, wash 3 times with distilled water, and dry at 60 °C to obtain the modified arabic gum.

[0064] The preparation method of the above-mentioned disease-resistant crop special fertilizer includes the following steps:

[0065] Step 1. Prepare a nutrient core: Weigh nitrogen fertilizer, phosphate fertilizer, potassium fertilizer, and synergist according to the weight ratio, mix them evenly and granulate to make fertilizer particles. Place the fertilizer particles in a constant temperature drying oven at 42 °C for 2 h, then add them to a coating device, and spray and coat molasses on the surface of the nutrient core to obtain a nutrient core with a diameter of 2.8 mm.

[0066] Step 2, covering the microbial inoculant coating: Add the microbial protectant and the microbial inoculant carrier to the liquid microbial inoculant, shake well for 15 min, filter and collect the solid, and freeze-dry to obtain the microbial inoculant coating material. Then spray and cover the microbial inoculant coating material on the surface of the nutrient core to obtain a nutrient core covered with the microbial inoculant coating, with a diameter of 3.2 mm.

[0067] Step 3, covering the medium and trace element coating: Heat the nutrient core covered with the microbial inoculant coating to 42 °C, spray and cover the nutrient core with the microbial inoculant coating with the encapsulant, and then further spray the medium and trace element fertilizer on the surface. After cooling and drying, the special fertilizer for disease-resistant crops is obtained, with a diameter of 3.7 mm.

[0068] Example 2

[0069] A special fertilizer for disease-resistant crops, the fertilizer is granular, and from the inside out, it includes a nutrient core, a microbial inoculant coating, and a medium and trace element coating; by weight, the nutrient core includes 40 parts of ammonium chloride, 20 parts of diammonium phosphate, 18 parts of potassium sulfate, 4 parts of alginic acid, and 1.5 parts of molasses; the microbial inoculant coating layer includes 1 part of liquid microbial inoculum, 1 part of microbial protectant, and 3 parts of microbial inoculant carrier; the medium and trace element coating layer includes 5 parts of medium and trace element fertilizer and 0.8 part of encapsulant.

[0070] Among them, the liquid microbial inoculum is composed of Bacillus subtilis, Bacillus mucilaginosus, and Pseudomonas fluorescens. The effective viable count of Bacillus subtilis is not less than 200 million / mL, the effective viable count of Bacillus mucilaginosus is not less than 200 million / mL, and the effective viable count of Pseudomonas fluorescens is not less than 500 million / mL.

[0071] Among them, the microbial protectant is a mixture of alginate oligosaccharide (average degree of polymerization is 4.5) and rhamnolipid in a mass ratio of 1:1.

[0072] Among them, the preparation method of the microbial inoculant carrier includes:

[0073] S1. Grind 1 g of diatomaceous earth and pass it through a 150-mesh sieve, add it to 10 mL of 1 mol / L sulfuric acid solution, stir and react for 1.5 h, then wash with water until the filtrate is neutral, and then dry at 105 °C to obtain the aged diatomaceous earth.

[0074] S2. Add 0.13 g of manganese sulfate and 0.2 g of ferric sulfate to 10 mL of deionized water to form a sulfate solution; add 1 g of the aged diatomaceous earth, and mix well until uniform to obtain a diatomaceous earth mixture.

[0075] S3. Add 1 g of humic acid 50 kDa to 5 mL of sodium hydroxide solution at pH = 8-9, and stir until fully dissolved to obtain a humic acid solution; add the humic acid solution dropwise into the diatomaceous earth mixture, the volume ratio of the humic acid solution to the diatomaceous earth mixture is 1:3, and stir continuously during the addition. After the addition is completed, adjust the pH of the system to 4-6, let it stand for 10 hours, dry under reduced pressure, wash with distilled water 3 times, and dry at 105°C to obtain a microbial agent carrier.

[0076] Among them, the medium and trace element fertilizer is composed of magnesium sulfate, diammonium ferric humate, copper sulfate monohydrate, zinc sulfate monohydrate, manganese sulfate and sodium molybdate in a mass ratio of 1:1:1:1:1:1:1.

[0077] Wherein, the encapsulating agent is modified gum arabic, and the preparation method comprises:

[0078] S10, weigh 1g chitosan and dissolve it in 10mL, 2wt% acetic acid solution, add 80wt% phosphoric acid solution dropwise, the added amount is 1:4 of the volume of the acetic acid solution, heat to 50°C, stir for 10h, after the treatment, pour into 2 times volume of ethanol, collect the precipitate, wash with ethanol 3 times, and dry at 60°C to obtain phosphorylated chitosan;

[0079] S11, dissolving phosphorylated chitosan in distilled water to prepare a phosphorylated chitosan solution with a mass fraction of 1%; first dissolving gum arabic in a sodium hydroxide solution with a mass fraction of 0.5%, heating the solution to 50° C., and then diluting it with distilled water to prepare a gum arabic solution with a mass fraction of 2-4%;

[0080] S12. Slowly add the phosphorylated chitosan solution into the gum arabic solution, the volume ratio of the gum arabic solution to the phosphorylated chitosan solution is 2:1, stir at 50°C and 600rpm for 2h, then adjust the pH of the system to 5-6, filter, wash with distilled water for 3 times, and dry at 60°C to obtain the modified gum arabic.

[0081] The method for preparing the disease-resistant crop fertilizer comprises the following steps:

[0082] Step 1, preparing nutrient core: according to the weight ratio, nitrogen fertilizer, phosphorus fertilizer, potassium fertilizer and synergist are weighed, mixed evenly and granulated into fertilizer granules, the fertilizer granules are placed at 40°C and dried at a constant temperature for 2 hours, and then added to the coating device, and molasses is sprayed on the surface of the nutrient core to obtain a nutrient core with a diameter of 2.6 mm;

[0083] Step 2, Coating with microbial inoculant coating: Add microbial protectant and microbial inoculant carrier into liquid microbial inoculant, shake well for 10 min, filter and collect the solid, and obtain the microbial inoculant coating material by freeze-drying. Then spray and coat the microbial inoculant coating material on the surface of the nutrient core to obtain a nutrient core coated with microbial inoculant coating, with a diameter of 3.0 mm;

[0084] Step 3, Coating with medium and trace element coating: Heat the nutrient core coated with microbial inoculant coating to 40 °C, spray and coat the wrapping agent on the nutrient core coated with microbial inoculant coating, and then further spray medium and trace element fertilizer on the surface. After cooling and drying, the special fertilizer for disease-resistant crops is obtained, with a diameter of 3.5 mm.

[0085] Example 3

[0086] A special fertilizer for disease-resistant crops, the fertilizer is granular, and from the inside out, it includes a nutrient core, a microbial inoculant coating, and a medium and trace element coating; by weight, the nutrient core includes 35 parts of ammonium nitrate, 25 parts of superphosphate, 15 parts of potassium sulfate, 4 parts of chitosan, and 1.5 parts of molasses; the microbial inoculant coating layer includes 2 parts of liquid microbial inoculant, 2 parts of microbial protectant, and 5 parts of microbial inoculant carrier; the medium and trace element coating layer includes 10 parts of medium and trace element fertilizer and 1.6 parts of wrapping agent.

[0087] Among them, the liquid microbial inoculant is composed of Bacillus subtilis, Bacillus mucilaginosus, and Pseudomonas fluorescens. The effective viable count of Bacillus subtilis is not less than 200 million / mL, the effective viable count of Bacillus mucilaginosus is not less than 200 million / mL, and the effective viable count of Pseudomonas fluorescens is not less than 500 million / mL.

[0088] Among them, the microbial protectant is a mixture of alginate oligosaccharide (average degree of polymerization is 5) and rhamnolipid in a mass ratio of 1:1.

[0089] Among them, the preparation method of the microbial inoculant carrier includes:

[0090] S1. Grind 1 g of diatomite, sieve it through a 180-mesh sieve, add it to 20 mL of 1 mol / L sulfuric acid solution, stir and react for 2 h, then wash it with water until the filtrate is neutral, and then dry it at 105 °C to obtain aged diatomite;

[0091] S2. Add 0.18 g of manganese sulfate and 0.4 g of ferric sulfate to 20 mL of deionized water to form a sulfate solution; add 1 g of aged diatomite, and mix well until uniform to obtain a diatomite mixture;

[0092] S3. Add 1 g of 100 kDa humic acid to 10 mL of sodium hydroxide solution with pH = 8 - 9, stir until fully dissolved to obtain a humic acid solution; add the humic acid solution dropwise to the diatomite mixture, with the volume ratio of the humic acid solution to the diatomite mixture being 1:6. Stir continuously during the dropping process. After the dropping is completed, adjust the pH of the system to 4 - 6, let it stand for 20 h, perform reduced-pressure drying, wash it 5 times with distilled water, and dry it at 105 °C to obtain the microbial inoculum carrier.

[0093] Among them, the medium and trace element fertilizer consists of magnesium sulfate, ferrous ammonium humate, copper sulfate monohydrate, zinc sulfate monohydrate, manganese sulfate, and sodium molybdate in a mass ratio of 1:1:1:1:1:1.

[0094] Among them, the coating agent is modified arabic gum, and the preparation method includes:

[0095] S10. Weigh 1 g of chitosan and dissolve it in 20 mL of 4 wt% acetic acid solution. Dropwise add 85 wt% phosphoric acid solution, and the added amount is 1:6 of the volume of the acetic acid solution. Heat it to 60 °C and stir for 15 h. After the treatment is completed, pour it into 3 times the volume of ethanol, collect the precipitate, wash it 3 times with ethanol, and dry it at 60 °C to obtain phosphorylated chitosan.

[0096] S11. Dissolve the phosphorylated chitosan in distilled water to make a 3% mass fraction phosphorylated chitosan solution; first dissolve arabic gum in a 2.5% mass fraction sodium hydroxide solution, heat the solution to 50 °C, and then dilute it with distilled water to make a 4% mass fraction arabic gum solution.

[0097] S12. Slowly add the phosphorylated chitosan solution to the arabic gum solution, with the volume ratio of the arabic gum solution to the phosphorylated chitosan solution being 3:1. Stir at 60 °C at a speed of 600 rpm for 4 h, then adjust the pH of the system to 5 - 6, filter, wash it 5 times with distilled water, and dry it at 60 °C to obtain the modified arabic gum.

[0098] The preparation method of the above-mentioned disease-resistant crop special fertilizer includes the following steps:

[0099] Step 1. Prepare the nutrient core: Weigh nitrogen fertilizer, phosphate fertilizer, potassium fertilizer, and synergist according to the weight ratio, mix them evenly and granulate them into fertilizer particles. Place the fertilizer particles in a constant temperature drying oven at 42 °C for 2 h, then add them to the coating device, and spray and coat molasses on the surface of the nutrient core to obtain the nutrient core with a diameter of 2.8 mm.

[0100] Step 2, covering the microbial inoculant coating: Add the microbial protectant and the microbial inoculant carrier to the liquid microbial inoculant, shake well and contact for 15 min, filter and collect the solid, and freeze-dry to obtain the microbial inoculant coating material. Then spray and cover the microbial inoculant coating material on the surface of the nutrient core to obtain a nutrient core covered with the microbial inoculant coating, with a diameter of 3.2 mm.

[0101] Step 3, covering the medium and trace element coating: Heat the nutrient core covered with the microbial inoculant coating to 42 °C, spray and cover the wrapping agent on the nutrient core with the microbial inoculant coating, and then further spray the medium and trace element fertilizer on the surface. After cooling and drying, the special fertilizer for disease-resistant crops is obtained, with a diameter of 3.7 mm.

[0102] Comparative Example 1

[0103] A granular fertilizer, different from Example 1 in that no coating treatment is carried out, the microbial inoculant carrier, the microbial protectant and the wrapping agent are not added, and other components remain unchanged.

[0104] By weight, it includes 37 parts of urea, 22 parts of monoammonium phosphate, 18 parts of potassium chloride, 4 parts of humic acid, 1 part of molasses, 1.5 parts of microbial inoculant (where the effective viable count of Bacillus subtilis is not less than 200 million / g, the effective viable count of Bacillus mucilaginosus is not less than 200 million / g, and the effective viable count of Pseudomonas fluorescens is not less than 500 million / g), and 7 parts of medium and trace element fertilizer (composed of magnesium sulfate, ammonium ferrous dihydroxyethylenediaminetetraacetate, copper sulfate monohydrate, zinc sulfate monohydrate, manganese sulfate and sodium molybdate in a mass ratio of 1:1:1:1:1:1). The fertilizer particles with a diameter of 3.7 mm are obtained by granulation and screening.

[0105] Comparative Example 2

[0106] A coated granular fertilizer, different from Example 1 in that the microbial protectant is not added, the microbial inoculant carrier is replaced with ordinary diatomaceous earth, and the wrapping agent is replaced with arabic gum, and other components remain unchanged.

[0107] In parts by weight, the fertilizer is granular and consists of a nutrient core, a microbial inoculant coating, and a medium and trace element coating from the inside out; in parts by weight, the nutrient core includes 37 parts of urea, 22 parts of monoammonium phosphate, 18 parts of potassium chloride, 4 parts of humic acid, and 1 part of molasses; the microbial inoculant coating layer includes 1.5 parts of a liquid microbial inoculant composed of Bacillus subtilis, Bacillus mucilaginosus, and Pseudomonas fluorescens (where the effective viable count of Bacillus subtilis is not less than 200 million / mL, the effective viable count of Bacillus mucilaginosus is not less than 200 million / mL, and the effective viable count of Pseudomonas fluorescens is not less than 500 million / mL), 4 parts of a microbial inoculant carrier (ordinary diatomaceous earth); the medium and trace element coating layer includes 7 parts of a medium and trace element fertilizer composed of magnesium sulfate, diammonium iron humate, copper sulfate monohydrate, zinc sulfate monohydrate, manganese sulfate, and sodium molybdate in a mass ratio of 1:1:1:1:1:1, and 0.8 parts of a coating agent (arabic gum).

[0108] Comparative Example 3

[0109] A coated granular fertilizer, different from Example 1 in that the microbial inoculant carrier is replaced with ordinary diatomaceous earth, and the coating agent is replaced with arabic gum and chitosan, with other components remaining unchanged.

[0110] In parts by weight, the fertilizer is granular and consists of a nutrient core, a microbial inoculant coating, and a medium and trace element coating from the inside out; in parts by weight, the nutrient core includes 37 parts of urea, 22 parts of monoammonium phosphate, 18 parts of potassium chloride, 4 parts of humic acid, and 1 part of molasses; the microbial inoculant coating layer includes 1.5 parts of a liquid microbial inoculant composed of Bacillus subtilis, Bacillus mucilaginosus, and Pseudomonas fluorescens (where the effective viable count of Bacillus subtilis is not less than 200 million / mL, the effective viable count of Bacillus mucilaginosus is not less than 200 million / mL, and the effective viable count of Pseudomonas fluorescens is not less than 500 million / mL), 1.5 parts of a microbial protectant (the same as in Example 1), 4 parts of a microbial inoculant carrier (ordinary diatomaceous earth); the medium and trace element coating layer includes 7 parts of a medium and trace element fertilizer composed of magnesium sulfate, diammonium iron humate, copper sulfate monohydrate, zinc sulfate monohydrate, manganese sulfate, and sodium molybdate in a mass ratio of 1:1:1:1:1:1, and 0.8 parts of a coating agent (arabic gum and chitosan with a mass ratio of 7.5:2).

[0111] Comparative Example 4

[0112] Conventional fertilizer compound fertilizer with a nitrogen-phosphorus-potassium ratio of 15-15-15.

[0113] Experimental detection

[0114] The test site was selected in a tomato planting area in Jingmen City, Hubei Province. The basic physical and chemical properties of the soil were as follows: pH = 7.41, organic matter content 3.26%, available nitrogen 92.4 mg / kg, available phosphorus 25.6 mg / kg, and available potassium 167.7 mg / kg. The test adopted a randomized block design, and the plot area was 60 m 2 , with a total of 7 treatments including Examples 1 - 3 and Comparisons 1 - 4. Each treatment had 3 replicates. The planting was carried out by the ridging method, and the fertilization amount for each treatment was 40 kg / mu. Except for the different types of fertilizers, other field measures such as sowing, irrigation, and weeding were the same. The picked tomatoes were used for the determination of soluble sugar, vitamin C, and lycopene content and the calculation of mu yield. At the same time, the disease incidence rates of early blight, gray mold, late blight, and leaf mold were measured.

[0115] Table 1 Comparison of quality and yield indexes of tomatoes under different treatments

[0116]

[0117] In terms of quality indexes, compared with the conventional compound fertilizer (Comparison 4) and the fertilizer without the double - layer coating structure (Comparison 1), after applying the disease - resistant crop - specific fertilizer of the present invention, the soluble sugar content, vitamin C content, and lycopene content of tomatoes were significantly improved. At the same time, there was also a certain degree of improvement compared with Comparisons 2 and 3. In terms of yield indexes, compared with the conventional compound fertilizer (Comparison 4) and the fertilizer without the double - layer coating structure (Comparison 1), after applying the disease - resistant crop - specific fertilizer of the present invention, the tomato yields increased by more than 17.03% and 10.79% respectively. At the same time, there was also a certain degree of improvement compared with Comparisons 2 and 3.

[0118] Table 2 Effects of different treatments on the disease incidence rate of tomatoes

[0119] Quality Index Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Early blight 1.9％ 2.0％ 2.3％ 8.5％ 5.8％ 4.2％ 13.4％ Gray mold 2.4％ 2.7％ 2.5％ 16.1％ 6.2％ 4.9％ 26.2％ Late blight 0.8％ 1.1％ 1.0％ 12.2％ 6.1％ 3.0％ 18.2％ Fulvia leaf mold 1.8％ 1.9％ 2.3％ 14.8％ 8.2％ 5.6％ 22.3％

[0120] It can be seen from Table 2 that compared with the conventional compound fertilizer (Comparison 4) and the fertilizer without the double - layer coating structure (Comparison 1), after applying the disease - resistant crop - specific fertilizer of the present invention, the number of diseased plants of early blight, gray mold, late blight, and leaf mold in tomatoes decreased significantly, and there was also a certain degree of improvement compared with Comparisons 2 and 3.

[0121] In summary, the disease - resistant crop - specific fertilizer provided by the present invention can improve the quality and yield of tomatoes, and at the same time can significantly reduce the impact of diseases such as early blight, gray mold, late blight, and leaf mold on tomatoes.

[0122] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0123] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A disease-resistant crop fertilizer, characterized in that: From the inside to the outside, it includes a nutrient core, a microbial agent coating, and a medium and trace element coating; in parts by weight, the nutrient core includes 35-40 parts of nitrogen fertilizer, 20-25 parts of phosphorus fertilizer, 15-20 parts of potassium fertilizer, 3-5 parts of synergist, and 1-1.5 parts of molasses; the microbial agent coating layer includes 1-2 parts of liquid microbial liquid, 1-2 parts of microbial protective agent, and 3-5 parts of microbial agent carrier; the medium and trace element coating layer includes 5-10 parts of medium and trace element fertilizer and 0.8-1.6 parts of encapsulating agent.

2. The disease-resistant crop fertilizer according to claim 1, characterized in that: The nitrogen fertilizer is one or more of urea, ammonium bicarbonate, ammonium sulfate, ammonium chloride, sodium nitrate, calcium nitrate, and ammonium nitrate; the phosphate fertilizer is one or more of monoammonium phosphate, diammonium phosphate, ammonium phosphate, ammonium polyphosphate, superphosphate, double superphosphate, calcium magnesium phosphate, and phosphate rock powder; the potassium fertilizer is one or more of potassium chloride and potassium sulfate.

3. The disease-resistant crop fertilizer according to claim 1, characterized in that: The synergist is one or more of humic acid, alginic acid, chitosan and amino acid.

4. The disease-resistant crop fertilizer according to claim 1, characterized in that: The medium and trace element fertilizer is one or more compounds of calcium, magnesium, iron, copper, zinc, manganese and molybdenum.

5. The disease-resistant crop fertilizer according to claim 1, characterized in that: The liquid microbial bacterial liquid consists of Bacillus subtilis, Bacillus gelatinosa and Pseudomonas fluorescens, wherein the effective live bacteria count of Bacillus subtilis is not less than 200 million / mL, the effective live bacteria count of Bacillus gelatinosa is not less than 200 million / mL, and the effective live bacteria count of Pseudomonas fluorescens is not less than 500 million / mL.

6. The disease-resistant crop fertilizer according to claim 1, characterized in that: The microbial protective agent is a mixture of brown algae oligosaccharide and rhamnolipid; the mass ratio of brown algae oligosaccharide to rhamnolipid is 1:1-1.

5.

7. The disease-resistant crop fertilizer according to claim 1, characterized in that: The preparation method of the microbial agent carrier comprises: S1, grinding the diatomaceous earth and passing it through a 150-180 mesh sieve, adding it to a 1 mol / L sulfuric acid solution, stirring and reacting for 1.5-2 hours, then washing with water until the filtrate is neutral, and then drying at 105°C to obtain aged diatomaceous earth; S2, adding manganese sulfate and ferric sulfate into deionized water to form a sulfate solution; adding aged diatomaceous earth, and mixing thoroughly until uniform, to obtain a diatomaceous earth mixed solution; S3. Add humic acid into a sodium hydroxide solution with a pH of 8-9, stir until fully dissolved, and obtain a humic acid solution; drop the humic acid solution into the diatomaceous earth mixed solution, stir continuously during the dropwise addition, adjust the pH of the system to 4-6 after the dropwise addition is completed, let stand for 10-20 hours, dry under reduced pressure, wash with distilled water 3-5 times, and dry at 105°C to obtain a microbial agent carrier.

8. The disease-resistant crop fertilizer according to claim 1, characterized in that: The encapsulating agent is modified gum arabic, and the preparation method comprises: S10, weigh chitosan and dissolve it in acetic acid solution, add phosphoric acid solution dropwise, heat to 50-60°C, stir for 10-15h, pour into ethanol after treatment, collect precipitate, wash with ethanol 3 times, and dry at 60°C to obtain phosphorylated chitosan; S11, dissolving phosphorylated chitosan in distilled water to prepare a phosphorylated chitosan solution; dissolving gum arabic in a sodium hydroxide solution, heating the solution to 50° C., and then diluting it with distilled water to prepare a gum arabic solution; S12, slowly adding the phosphorylated chitosan solution into the gum arabic solution, stirring at 50-60°C and 600rpm for 2-4h, then adjusting the pH of the system to 5-6, filtering, washing with distilled water for 3-5 times, and drying at 60°C to obtain the modified gum arabic.

9. A method for preparing the disease-resistant crop fertilizer according to claim 1, characterized in that: The steps include: Step 1, preparing the nutrient core: according to the weight ratio, nitrogen fertilizer, phosphorus fertilizer, potassium fertilizer and synergist are weighed, mixed evenly and granulated into fertilizer granules, the fertilizer granules are placed at 40-42° C. and dried at a constant temperature for 2 hours, and then a coating device is added to spray molasses on the surface of the nutrient core to obtain the nutrient core; Step 2, covering the microbial agent coating: adding the microbial protective agent and the microbial agent carrier to the liquid microbial agent, fully shaking and contacting for 10-15 minutes, filtering and collecting the solid, freeze-drying to obtain the microbial agent coating material, and then covering the microbial agent coating material on the surface of the nutrient core to obtain the nutrient core covered with the microbial agent coating; Step 3, covering with medium and trace element coating: heating the nutrient core covered with the microbial agent coating to 40-42°C, spraying the coating agent on the nutrient core covered with the microbial agent coating, and then further spraying medium and trace element fertilizer on the surface, and obtaining the disease-resistant crop special fertilizer after cooling and drying.

10. The method for preparing a disease-resistant crop fertilizer according to claim 9, characterized in that: The diameter of the nutrient core in the first step is 2.6-2.8 mm; the diameter of the nutrient core covered with the microbial agent film in the second step is 3.0-3.2 mm; the diameter of the disease-resistant crop fertilizer in the third step is 3.5-3.7 mm.

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