Compound microbial fertilizer as well as preparation method and application thereof

Abstract

The invention provides a compound microbial fertilizer as well as a preparation method and application thereof. The compound microbial fertilizer comprises the following components in parts by weight: 10-30 parts of a compound microbial agent, 20-50 parts of a microbial agent carrier, 30-50 parts of a compound fertilizer slow release agent and 10-30 parts of modified urea aldehyde. The prepared compound microbial fertilizer is applied to tomato growth tests, high yield, stem diameter growth value, vitamin C content and sugar-acid ratio can be obtained, the compound microbial fertilizer can act for a long time, release nutrient elements such as phosphorus, nitrogen and potassium, has the effects of preserving moisture and loosening soil, can increase the yield and quality of tomato fruits, and has the advantages of high yield, high stem diameter growth value, high vitamin C content and high sugar-acid ratio. The health of rhizomes is promoted and the eating taste is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microbial fertilizer, and particularly relates to a compound microbial bacterial fertilizer as well as a preparation method and application thereof. BACKGROUND

[0002] China has a large population and a small per capita arable land area. In order to obtain more food on limited land, fertilizers play an increasingly important role in agricultural production, improve soil fertility, promote crop growth, and have important significance for the evolution of soil quality and sustainable development of agriculture.

[0003] Traditional organic fertilizers are gradually abandoned due to time-consuming and laborious production, unhygienic, slow fertilizer effect, and the like. The increase in the application amount of chemical fertilizers also gradually shows many drawbacks. Environmental protection and food safety problems have become the most concerned topics of people in recent years. For example, the abuse of chemical fertilizers causes the eutrophication of rivers and lakes, destroys the ecological system, the high content of nitrate in underground water threatens human health, and long-term application of chemical fertilizers leads to soil compaction, reduction of organic humus content, and disorder of soil microbial community, and in a severe case, causes soil desertification, and hinders the sustainable development of agriculture.

[0004] Due to a large number of microorganisms existing in the soil and the rhizosphere of plants, the interaction between beneficial bacteria and plant roots can promote plant growth, and therefore research on microbial bacterial fertilizer is gradually developed. The microbial bacterial fertilizer itself has no nutrients, but can improve the soil environment and stimulate crop growth through a large number of beneficial bacterial strains, and is considered to be one of the most promising tools for sustainable improvement of agricultural productivity. By regulating the function of soil microorganisms, it is expected to reduce the current over-reliance of agriculture on chemical fertilizers.

[0005] The use of microbial bacterial fertilizer in combination with compound fertilizer can further improve the fertility and reduce pollution, but how to have a long-term effect, continuously provide nutrients for crops, and reduce the frequency of fertilization is still a problem to be solved. SUMMARY

[0006] The purpose of the present application is to provide a biological bacterial fertilizer and a preparation method and application thereof to solve the problems in the background art.

[0007] To achieve the above purpose, the present application provides a compound microbial bacterial fertilizer, characterized in that it comprises the following components by weight: 10-30 parts of compound microbial bacterial agent, 20-50 parts of bacterial agent carrier, 30-50 parts of compound fertilizer slow-release agent, and 10-30 parts of modified urea aldehyde.

[0008] The compound fertilizer slow-release agent is a polyacrylic acid type compound fertilizer slow-release agent.

[0009] The modified urea aldehyde is sucrose modified urea aldehyde.

[0010] As a further improvement, the complex microbial inoculant is prepared by mixing Bacillus subtilis, Bacillus mucilaginosus, Trichoderma harzianum, Bacillus amyloliquefaciens in a mass ratio of 2-4:1-3:0.5-2:1, inoculating, activating and fermenting.

[0011] As a further improvement, the nutrient elements of the compound fertilizer slow-release agent at least include phosphorus, nitrogen, potassium and silicon.

[0012] As a further improvement, the synthesis of the compound fertilizer slow-release agent comprises the following steps:

[0013] (1) diatomite, ammonium dihydrogen phosphate and potassium humate are added to a flask equipped with a condensation reflux tube, distilled water is added under stirring and the temperature is raised to 70-90℃, and after reaction for 4-8h, the temperature is lowered to 40-60℃;

[0014] (2) acrylic acid is adjusted to pH 4-5 with an inorganic base solution under water bath condition to obtain a mixed solution A; an initiator and a crosslinking agent are added to water and stirred to dissolve to obtain a mixed solution B;

[0015] (3) the mixed solution A is slowly added to step (1) for stirring mixing, then the mixed solution B is further added dropwise, after the dropwise addition is completed, the temperature is raised to 70-90℃, and the reaction is stopped when the reaction system is viscous and stirring is difficult, and the compound fertilizer slow-release agent is obtained after post-treatment.

[0016] As a further improvement, the inorganic base solution is a potassium hydroxide solution; the initiator is potassium persulfate; and the crosslinking agent is N,N-methylene bisacrylamide.

[0017] As a further improvement, the content of effective component phosphorus pentoxide in the ammonium dihydrogen phosphate is ≥60%, and the content of nitrogen is ≥12%; the content of effective component potassium oxide in the potassium humate is ≥12%, and the content of humic acid is ≥70%.

[0018] As a further improvement, the specification of the diatomite is 100-200 mesh.

[0019] As a further improvement, the synthesis of the modified urea aldehyde comprises the following steps:

[0020] (1) urea is weighed and placed in a beaker, then formaldehyde is added for stirring and dissolving, then an inorganic base solution is added dropwise, the pH of the system is adjusted to 7-9, and the system is reacted in a 30-50℃ water bath for 1-3h to obtain a urea aldehyde solution;

[0021] (2) sucrose and a catalyst are sequentially added to step (1), then an inorganic acid solution is added, the pH of the system is adjusted to 4-6, then a paste is obtained by reacting at 60-80℃, and the paste is extruded and granulated by an extruder, and the modified urea aldehyde is obtained after post-treatment.

[0022] As a further improvement, the inorganic base solution is a potassium hydroxide solution; the catalyst is copper sulfate; and the inorganic acid solution is a phosphoric acid solution.

[0023] As a further improvement, the microbial agent carrier is biochar.

[0024] The application provides a preparation method of a compound microbial fertilizer, and has the characteristics that the method comprises the following steps:

[0025] (1) spraying a compound microbial agent on a microbial agent carrier according to weight parts, and then drying to obtain microbial agent powder;

[0026] (2) mixing the microbial agent powder obtained in the step (1) with a compound fertilizer slow-release agent and modified urea aldehyde to obtain the compound microbial fertilizer.

[0027] The application further provides application of the compound microbial fertilizer in promoting growth of crop fruits and improving crop quality.

[0028] Compared with the prior art, the application has the beneficial effects that:

[0029] The application provides a compound microbial fertilizer and a preparation method thereof, and the compound microbial fertilizer is applied to growth tests of tomatoes, so that a higher yield, stem diameter growth value, vitamin C content and sugar-acid ratio can be obtained, which indicates that the compound microbial fertilizer can have a long-term effect, release nutrient elements such as phosphorus, nitrogen and potassium, has the effects of moisturizing and loosening soil, can increase the weight and yield of tomato fruits, promote the health of roots and stems, and improve the eating taste.

[0030] The Trichoderma harzianum in the compound microbial agent can inhibit fungal pathogenic bacteria, improve the soil environment, and form dominant colonies by common fermentation with Bacillus subtilis, Bacillus mucilaginosus and Bacillus amyloliquefaciens, live in the roots or inside of crops, secrete various functional enzymes, play the roles of nitrogen fixation, phosphorus solubilization and potassium solubilization, promote the absorption of nutrients by crops, and improve the quality of crops. DETAILED DESCRIPTION

[0031] The application will be described below in combination with specific embodiments. It should be noted that the following examples are only used to illustrate the application, and are not used to limit the application. Other combinations and various modifications within the concept of the application can be made without departing from the main idea or scope of the application.

[0032] In the following examples, the remaining compounds used in the examples, except for microbial inoculant, compound fertilizer slow-release agent, modified urea aldehyde, urea aldehyde, can be purchased from the market, wherein Bacillus subtilis, Bacillus mucilaginosus, Trichoderma harzianum, Bacillus amyloliquefaciens are purchased from Beijing Keda Biological Technology Co., Ltd., product numbers are CMCC(B)63501, BNCC335819, BNCC336568, BNCC132483 respectively, potassium humate is purchased from Xinjiang Longjia Humic Acid Co., Ltd., ammonium dihydrogen phosphate is purchased from Jinan Zhucheng Chemical Co., Ltd., diatomite is purchased from Lingshou Zhuole Building Material Co., Ltd., sucrose and urea are purchased from Tianjin Kemio Chemical Reagent Co., Ltd., biochar is purchased from Henan Xingnuo Environmental Protection Material Co., Ltd.; commercially available compound fertilizer slow-release agent is purchased from Gansu Sudi Fertilizer Co., Ltd., model number is 8-12-5.

[0033] Preparation of microbial inoculant, comprising the following steps:

[0034] Bacillus subtilis, Bacillus mucilaginosus, Trichoderma harzianum and Bacillus amyloliquefaciens strains are inoculated in NB medium (formula: peptone 10 g, beef extract 3 g, NaCl 5 g, distilled water 1 L, pH = 7.2-7.4) respectively, and activated in a constant temperature incubator at 150 r / min and 30℃ for 12 h to obtain activated bacterial solution; 1 mL of activated bacterial solution is inoculated in a 100 mL volumetric flask containing 50 mL of NB medium, and seed solution is prepared by shaking at 30℃ for 24 h at a speed of 200 r / min.

[0035] (2) The seed solution is inoculated in a 100 L liquid fermentation tank for fermentation culture, and the culture is incubated until the absorbance of the suspension is OD 600 ≈1.0, to obtain fermentation liquor of the four strains, and then mixed according to a mass ratio of 3:2:1:1 to obtain microbial inoculant.

[0036] Synthesis of compound fertilizer slow-release agent, comprising the following steps:

[0037] (1) 10 g of diatomite, 20 g of ammonium dihydrogen phosphate and 20 g of potassium humate are added to a flask equipped with a condensation reflux tube, 200 mL of distilled water is added under stirring and heated to 80℃, and after reaction for 6 h, the temperature is lowered to 50℃;

[0038] (2) 100 g of acrylic acid is adjusted to pH 4.5 with 1 mol / L potassium hydroxide solution under 5℃ water bath condition to obtain mixed solution A; 2.2 g of potassium persulfate and 0.3 g of N,N-methylene bisacrylamide are added to 100 mL of water and stirred to dissolve to obtain mixed solution B;

[0039] (3) Slowly add the mixed solution A to the stirring mixture in step (1), then add the mixed solution B to it, and then raise the temperature to 80℃. Stop the reaction when the reaction system is sticky and stirring is difficult. Take out the reaction product, wash repeatedly with anhydrous ethanol, and then dry and crush at 80℃ to obtain the slow-release agent for compound fertilizer.

[0040] The synthesis of modified urea aldehyde comprises the following steps:

[0041] (1) Weigh 50g of urea into a beaker, then add 17.86g of formaldehyde, and then add a 5% potassium hydroxide solution by mass concentration after the urea is completely dissolved. Adjust the pH of the system to 8, and then react in a 40℃ water bath for 1.5h to obtain a urea aldehyde solution;

[0042] (2) Add 7.57g of sucrose and 0.75g of copper sulfate to step (1) in sequence, then add a 2% phosphoric acid solution by mass concentration, adjust the pH of the system to 5, and then react at 70℃ for 40min to obtain a paste, and then extrude and granulate with an extruder, and then dry at 80℃ to constant weight to obtain modified urea aldehyde.

[0043] The synthesis of urea aldehyde comprises the following steps:

[0044] (1) Weigh 50g of urea into a beaker, then add 17.86g of formaldehyde, and then add a 5% potassium hydroxide solution by mass concentration after the urea is completely dissolved. Adjust the pH of the system to 8, and then react in a 40℃ water bath for 1.5h to obtain a urea aldehyde solution;

[0045] (2) Add a 2% phosphoric acid solution by mass concentration to the urea aldehyde solution, adjust the pH of the system to 5, and then react at 70℃ for 40min to obtain a paste, and then extrude and granulate with an extruder, and then dry at 80℃ to constant weight to obtain urea aldehyde.

[0046] The preparation method of examples 1-3 and comparative examples 1-3 comprises the following steps:

[0047] (1) Spray the compound microbial agent on the microbial agent carrier according to the weight fraction, and then dry naturally at room temperature to obtain microbial powder;

[0048] (2) Mix the microbial powder obtained in step (1) with the slow-release agent for compound fertilizer and modified urea aldehyde to obtain a compound microbial fertilizer.

[0049] The components and contents used in examples 1-3 and comparative examples 1-3 are shown in Table 1 below:

[0050] Table 1

[0051]

[0052] Promoting growth test of the composite microbial fertilizer prepared from the polyacrylic acid type compound fertilizer slow release agent of the application and the compound fertilizer slow release agent of the prior art was carried out on tomato seedlings, and the test method was as follows.

[0053] Test area setting: 7 different treatments were set, including blank control group, examples 1-3 and comparative examples 1-3, and the tomato seedlings (variety Zhefen 702) were planted in the test area soil, and the area of each small area was 18.0 m 2 ; each treatment was repeated 3 times, and the random block arrangement was adopted, and the planting was carried out in the way of ridge, the ridge height was about 0.3 m, the plant spacing was 0.3 m, and 50 cm x 20 cm ridges were set around each small area to separate the adjacent small areas;

[0054] Fertilization method: the tomato seedlings were planted in each test area, and the blank control group was not fertilized but watered during the planting period; the rest used the composite microbial fertilizer of examples 1-3 and comparative examples 1-3 for fertilization, and the fertilization amount was 1000 kg / hm 2 .

[0055] After the fruit ripened, picking was started, and the yield of each area was recorded according to the area setting; the stem diameter before and after planting was measured by a vernier caliper to obtain the stem diameter growth value; the content of organic acid (total acid) in the tomato fruit was measured according to the method in the national standard "Determination of total acid in food", the content of vitamin C in the tomato fruit was measured by iodometric method; the content of soluble sugar in the tomato fruit was measured by anthrone colorimetry, and the sugar acid ratio was calculated according to the ratio of total soluble sugar to total acid.

[0056] The test results are shown in Table 2, and the details are as follows:

[0057] Table 2

[0058]

[0059] As can be seen from examples 2 and comparative examples 1-2 in Table 2, compared with the composite microbial fertilizer prepared by using conventional compound fertilizer or commercially available compound fertilizer slow release agent, the composite microbial fertilizer prepared by using the polyacrylic acid type compound fertilizer slow release agent has higher yield, stem diameter growth value, vitamin C content and sugar acid ratio in the growth test of tomato, which indicates that the polyacrylic acid type compound fertilizer slow release agent prepared by grafting polyacrylic acid as coating material and the material containing phosphorus, nitrogen and potassium nutrients can have long-term effect, increase the yield and quality of tomato fruit, promote the health of roots and stems, and improve the eating taste; and since diatomite itself can absorb water and is light, it can play the role of moisture retention and soil loosening in the soil, and can be used as a long-acting silicon fertilizer in cooperation with phosphorus, nitrogen and potassium, to further promote the growth of crops.

[0060] As can be seen from the example 2 and the comparative example 3, compared with the composite microbial fertilizer prepared by using unmodified urea aldehyde, the composite microbial fertilizer prepared by using the urea aldehyde modified by sucrose has higher yield, stem diameter growth value, vitamin C content and sugar acid ratio in the growth test of tomatoes, which indicates that the introduction of sucrose can improve the release efficiency of nitrogen elements and organic matters in the soil, stimulate the urease activity of the soil, provide favorable conditions for the growth and reproduction of microorganisms in the soil, and improve the yield of crops.

[0061] As can be seen from the test results of the examples 1-3, the composite microbial fertilizer prepared by the preparation method provided by the application can be applied to the growth test of tomatoes, and higher yield, stem diameter growth value, vitamin C content and sugar acid ratio can be obtained, which indicates that the composite microbial fertilizer can have long-term effect, release phosphorus, nitrogen, potassium and other nutrient elements, and has the effects of moisturizing and loosening soil, can increase the yield and quality of tomato fruits, promote the health of roots and stems, and improve the eating taste.

[0062] The above embodiments are only for illustrating the technical concept and characteristics of the application, and the purpose is to enable the person skilled in the art to understand the content of the application and implement it, and cannot limit the protection scope of the application, and any equivalent changes or modifications made according to the spirit and essence of the application should be covered within the protection scope of the application.

Claims

1. A composite microbial fertilizer, characterized in that: The invention comprises the following components in parts by weight: 10-30 parts of a composite microbial agent, 20-50 parts of an agent carrier, 30-50 parts of a compound fertilizer slow-release agent, and 10-30 parts of modified urea aldehyde; The compound fertilizer slow-release agent is a polyacrylic acid type compound fertilizer slow-release agent; The modified urea aldehyde is sucrose modified urea aldehyde.

2. A composite microbial fertilizer according to claim 1, characterized in that The composite microbial agent is prepared by mixing Bacillus subtilis, Bacillus mucilaginosus, Trichoderma harzianum and Bacillus amyloliquefaciens in a mass ratio of 2-4:1-3:0.5-2:1, and undergoing inoculation, activation and fermentation.

3. A composite microbial fertilizer according to claim 1, characterized in that: The nutrient elements of the compound fertilizer slow-release agent at least include phosphorus, nitrogen, potassium and silicon.

4. A composite microbial fertilizer according to claim 1, characterized in that The synthesis of the compound fertilizer slow-release agent comprises the following steps: (1) Add diatomaceous earth, ammonium dihydrogen phosphate, and potassium humate to a flask equipped with a condenser reflux tube, add distilled water while stirring, and heat to 70-90°C. After reacting for 4-8 hours, cool to 40-60°C; (2) adjusting the pH of acrylic acid to 4-5 with an inorganic alkaline solution in a water bath to obtain a mixed solution A; adding an initiator and a cross-linking agent to water and stirring to dissolve, to obtain a mixed solution B; (3) Slowly drop the mixed solution A into step (1) and stir to mix, then drop the mixed solution B therein, raise the temperature to 70-90° C. after the addition, stop the reaction when the reaction system becomes viscous and difficult to stir, and perform post-processing to obtain a compound fertilizer slow-release agent.

5. A composite microbial fertilizer according to claim 4, characterized in that: The effective component phosphorus pentoxide content in the ammonium dihydrogen phosphate is ≥60%, and the nitrogen content is ≥12%; the effective component potassium oxide content in the potassium humate is ≥12%, and the humic acid content is ≥70%.

6. A composite microbial fertilizer according to claim 4, characterized in that: The specification of the diatomaceous earth is 100-200 meshes.

7. A composite microbial fertilizer according to claim 1, characterized in that: The synthesis of the modified urea-aldehyde comprises the following steps: (1) Weigh urea and place it in a beaker, then add formaldehyde and stir to dissolve, then dropwise add an inorganic alkali solution, adjust the pH of the system to 7-9, and react in a water bath at 30-50°C for 1-3 hours to obtain a urea-aldehyde solution; (2) Sucrose and a catalyst are sequentially added to step (1), and then an inorganic acid solution is added to adjust the pH of the system to 4-6, followed by reaction at 60-80° C. to obtain a paste, which is extruded and granulated using an extruder, and post-processed to obtain modified urea aldehyde.

8. A composite microbial fertilizer according to claim 1, characterized in that: The bacterial agent carrier is biochar.

9. The method for preparing a composite microbial fertilizer according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) spraying the composite microbial agent onto a microbial agent carrier according to weight, and then drying to obtain microbial powder; (2) The microbial powder obtained in step (1) is mixed with a compound fertilizer slow-release agent and modified urea-aldehyde to obtain a compound microbial fertilizer.

10. Use of the composite microbial fertilizer according to any one of claims 1 to 8 in promoting the growth of crop fruits and improving the quality of crops.

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