Chitosan-based liquid medical fertilizer and preparation method thereof

Abstract

The invention belongs to the technical field of slow release of medical fertilizers, and particularly relates to a chitosan-based liquid medical fertilizer and a preparation method thereof. A chitosan-based nano material is used as a pesticide carrier, a bactericidal active component is used as a load, the nano bactericide is prepared, and gamma-polyglutamic acid is used for wrapping the nano bactericide to prepare the liquid pesticide fertilizer. The chitosan-based liquid pesticide fertilizer provided by the invention is simple in preparation process, the prepared liquid pesticide fertilizer is good in biocompatibility and safe to the environment, the labor cost and the economic cost can be reduced by simultaneously applying the pesticide and the fertilizer, the problem that most pesticides are lost into soil and atmosphere can be solved, and the chitosan-based liquid pesticide fertilizer has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of sustained-release medicinal fertilizer, and in particular relates to a chitosan-based liquid medicinal fertilizer and a preparation method thereof. Background Art

[0002] Wheat stem rot is a disease in wheat production caused by the combined infection of pathogens such as Pseudomonas graminearum and Fusarium graminearum. The pathogen can survive for a long time in the soil and plant diseased residues. Wheat stem rot is one of the soil-borne diseases. After the disease occurs, it spreads quickly and causes damage to a wide range. It will cause serious reduction in wheat production and reduce grain quality. It has become one of the main diseases restricting the healthy development of the wheat industry.

[0003] In order to increase wheat production and prevent and control wheat diseases and pests, many wheat growers apply large amounts of chemical fertilizers and pesticides during the wheat production process. This not only causes pesticide residues in wheat grains, but also leads to a decrease in the organic matter content in the soil, affecting the ecological structure of the soil, reducing the number of beneficial bacteria, and thereby increasing the probability of wheat stem rot. It also poses a great threat to the environment on which people depend for survival and deepens people's concerns about food security and environmental safety. Therefore, there is an urgent need for an environmentally friendly, pesticide and fertilizer control method that leaves less residue in the soil and can increase wheat production to control wheat diseases and pests.

[0004] In addition, most of the current liquid fertilizers are mixed with liquid fertilizers and pesticides, which may have unreasonable ratios of fertilizers and drugs, produce adverse chemical reactions, thereby polluting the environment, and causing great damage to crops. In recent years, nanoparticles have been used in agriculture due to their unique physical and chemical properties, and have broad application prospects. The application of chitosan-based nanoparticles in agricultural delivery systems and colloidal nano delivery systems loaded with pesticides also provides a feasibility reference for the implementation of the present invention. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a chitosan-based liquid medicated fertilizer and a preparation method thereof. The chitosan-based liquid medicated fertilizer of the present invention can solve the above problems to a certain extent. The medicated fertilizer product realizes the two-in-one of pesticides and fertilizers. The simultaneous application of pesticides and fertilizers reduces labor intensity and time. The liquid medicated fertilizer of the present invention is easy to use, safe for the environment, has little residue in the soil, and can improve the effective utilization rate of pesticides and fertilizers.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] The first technical purpose of the present invention is to provide a chitosan-based liquid medicinal fertilizer, wherein the chitosan-based liquid medicinal fertilizer comprises the following components based on the total weight of the liquid medicinal fertilizer:

[0008] 1.2 parts of chitosan, 1.6 parts of carboxymethyl chitosan, 4-16 parts of gamma-polyglutamic acid, 0.086-0.284 parts of bactericidal active ingredients, 2 parts of glutaraldehyde, 3 parts of liquid paraffin, 0.5-1.5 parts of Tween, 0.5-1.5 parts of Span, and 1300-1500 parts of water.

[0009] Optionally, the bactericidal active ingredient is one of meconium chloride, tebuconazole and fludioxonil.

[0010] A second technical purpose of the present invention is to provide a method for preparing the chitosan-based liquid fertilizer as described above.

[0011] The preparation method of the chitosan-based liquid fertilizer specifically comprises the following steps:

[0012] Step 1, using chitosan-based nanomaterials as carriers and bactericidal active ingredients as loads to prepare nano bactericides;

[0013] Step 2: using γ-polyglutamic acid to encapsulate the nano bactericide to obtain the chitosan-based liquid fertilizer.

[0014] Optionally, the chitosan-based nanomaterial is prepared as follows:

[0015] Liquid paraffin is dripped into the chitosan solution, and then a certain amount of glutaraldehyde solution is added. After a period of reaction, carboxymethyl chitosan solution is added, and chitosan-based nanomaterials are obtained after cross-linking.

[0016] Furthermore, the volume ratio of the γ-polyglutamic acid solution to the chitosan solution is 1:1-2:1, the volume ratio of the chitosan solution to the carboxymethyl chitosan solution is 1:1, and the concentration of the γ-polyglutamic acid solution is 1-4 g / L.

[0017] Furthermore, the bactericidal active ingredient is added after glutaraldehyde is added and reacted for a period of time, and Tween 80 and Span 80 are added for emulsification before the glutaraldehyde solution is added.

[0018] Furthermore, the reaction system requires conditions of 45°C in a water bath with continuous stirring.

[0019] Furthermore, the volume ratio of Tween 80 to Span 80 is 1:1-1:2.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The chitosan-based liquid fertilizer prepared by the present invention has a simple production process, is safe for the environment, and is easy to use. It can be used by spraying or by root irrigation.

[0022] 2. The chitosan-based liquid fertilizer prepared by the present invention is an application technology that combines disease prevention agents with foliar fertilizers and applies pesticides and fertilizers at the same time, which can not only improve the utilization rate of pesticides, but also reduce the use of chemical fertilizers, and reduce time costs, labor costs and economic costs.

[0023] 3. The chitosan-based liquid fertilizer prepared by the present invention encapsulates the bactericidal active ingredients in chitosan-based nanomaterials, effectively reducing the loss of pesticides, extending their effective period, and reducing the pollution of pesticides to the soil and the environment, thereby improving crop quality.

[0024] 4. The chitosan-based liquid fertilizer prepared by the present invention uses γ-polyglutamic acid to encapsulate the nano-fungicide, which can not only improve the sustained-release performance of the pesticide, but also provide a large number of essential elements required for plant growth, thereby providing nutrition for wheat growth.

[0025] 5. During the growth process of wheat, the application of pesticides and amino acids can prevent the occurrence of wheat diseases and promote the growth of wheat roots. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0027] Figure 1 This is a scanning electron microscope image of the chitosan-based liquid medicinal fertilizer product of Example 1 of the present invention. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this application are performed using conventional test methods in the art. It should be understood that the terms described in this application are only used to describe specific implementation methods and are not used to limit the content disclosed in this application.

[0030] Unless otherwise specified, the technical and scientific terms used in this document have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0031] In order to better illustrate the content of the present application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present application.

[0032] Under the premise of no conflict, the technical features disclosed in the embodiments of the present application can be combined arbitrarily, and the resulting technical solutions belong to the contents disclosed in the embodiments of the present application.

[0033] The invention discloses a chitosan-based liquid medicinal fertilizer and a preparation method thereof.

[0034] In order to better understand the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as a limitation of the present invention. Some non-essential improvements and adjustments made by technicians in this field based on the above invention content are also considered to fall within the protection scope of the present invention.

[0035] Embodiment 1:

[0036] During the growth process of wheat, chitosan-based liquid fertilizer was applied in mid-to-late September, late February, early March, mid-March, mid-April, late April, early May, mid-May, and late May.

[0037] Chitosan-based liquid fertilizer is prepared according to the following steps:

[0038] (1) 400 μL of acetic acid solution was added to 39.60 mL of distilled water, and 120 mg of chitosan was slowly added at 550 r / min to completely dissolve the chitosan, followed by ultrasonic oscillation for 2 h (ultrasonic frequency: 40 kHz) to obtain the first solution;

[0039] (2) adding 160 mg of carboxymethyl chitosan into 40.0 mL of distilled water at 550 r / min to completely dissolve the carboxymethyl chitosan to obtain a second solution;

[0040] (3) dissolving 200 μL of 50% glutaraldehyde in 19.80 mL of distilled water to obtain a third solution;

[0041] (4) dissolving 0.8 g of γ-polyglutamic acid in 400 mL of distilled water at 550 r / min until completely dissolved to obtain a fourth solution;

[0042] (5) Under stirring in a 45°C water bath, add 300 μL of liquid paraffin to 40.0 mL of the first solution and stir for 30 min.

[0043] (6) Add 200 μL of a mixed solution of Tween 80 and Span 80 (volume ratio 1:1) and emulsify for 30 min to obtain the fifth solution;

[0044] (7) Weigh 13.2 mg of tebuconazole original drug and dissolve it in 500 μL of dimethyl sulfoxide solution. After ultrasonic oscillation for 1 min, add it to the fifth solution and react for 30 min.

[0045] (8) Add 12.0 mL of the third solution dropwise using a peristaltic pump and react for 1 h to obtain the sixth solution;

[0046] (9) Using a peristaltic pump, 40.0 mL of the second solution was added dropwise to the sixth solution and reacted for 1.5 h to obtain the seventh solution;

[0047] (10) Using a peristaltic pump, 40.0 mL of the fourth solution was added to the seventh solution and reacted for 1.5 h to obtain the final chitosan-based liquid fertilizer.

[0048] Chitosan-based liquid fertilizer needs to be diluted when applied, and the volume ratio of chitosan to water is 1:10. It is used for root irrigation at the roots of wheat plants, with 150 mL applied to each plant.

[0049] Embodiment 2:

[0050] During the growth process of wheat, chitosan-based liquid fertilizer was applied in mid-to-late September, late February, early March, mid-March, mid-April, late April, early May, mid-May, and late May.

[0051] Chitosan-based liquid fertilizer is prepared according to the following steps:

[0052] (1) 400 μL of acetic acid solution was added to 39.60 mL of distilled water, and 120 mg of chitosan was slowly added at 550 r / min to completely dissolve the chitosan, followed by ultrasonic oscillation for 2 h (ultrasonic frequency: 40 kHz) to obtain the first solution;

[0053] (2) adding 160 mg of carboxymethyl chitosan into 40.0 mL of distilled water at 550 r / min to completely dissolve the carboxymethyl chitosan to obtain a second solution;

[0054] (3) dissolving 200 μL of 50% glutaraldehyde in 19.80 mL of distilled water to obtain a third solution;

[0055] (4) dissolving 0.8 g of γ-polyglutamic acid in 400 mL of distilled water at 550 r / min until completely dissolved to obtain a fourth solution;

[0056] (5) Under stirring in a 45°C water bath, add 300 μL of liquid paraffin to 40.0 mL of the first solution and stir for 30 min.

[0057] (6) Add 200 μL of a mixed solution of Tween 80 and Span 80 (volume ratio 1:1) and emulsify for 30 min to obtain the fifth solution;

[0058] (7) Weigh 19.8 mg of tebuconazole original drug and dissolve it in 500 μL of dimethyl sulfoxide solution. After ultrasonic oscillation for 1 min, add it to the fifth solution and react for 30 min.

[0059] (8) Add 12.0 mL of the third solution dropwise using a peristaltic pump and react for 1 h to obtain the sixth solution;

[0060] (9) Using a peristaltic pump, 40.0 mL of the second solution was added dropwise to the sixth solution and reacted for 1.5 h to obtain the seventh solution;

[0061] (10) Using a peristaltic pump, 40.0 mL of the fourth solution was added to the seventh solution and reacted for 1.5 h to obtain the final chitosan-based liquid fertilizer.

[0062] Chitosan-based liquid fertilizer needs to be diluted when applied, and the volume ratio of chitosan to water is 1:10. It is used for root irrigation at the roots of wheat plants, with 150 mL applied to each plant.

[0063] In order to further demonstrate the beneficial effects of the present invention and to better understand the present invention, the following comparative examples and test examples are used to further illustrate the technical features disclosed in the present invention, but they should not be understood as limiting the present invention. Other improvements made by those skilled in the art based on the above invention content without creative work are also considered to fall within the scope of protection of the present invention.

[0064] Comparative Example 1

[0065] During the growth process of wheat, chitosan-based liquid fertilizer was applied in mid-to-late September, late February, early March, mid-March, mid-April, late April, early May, mid-May, and late May.

[0066] Chitosan-based liquid fertilizer is prepared according to the following steps:

[0067] (1) 400 μL of acetic acid solution was added to 39.60 mL of distilled water, and 120 mg of chitosan was slowly added at 550 r / min to completely dissolve the chitosan, followed by ultrasonic oscillation for 2 h (ultrasonic frequency: 40 kHz) to obtain the first solution;

[0068] (2) adding 160 mg of carboxymethyl chitosan into 40.0 mL of distilled water at 550 r / min to completely dissolve the carboxymethyl chitosan to obtain a second solution;

[0069] (3) dissolving 48 mg of sodium tripolyphosphate in 12.0 mL of distilled water to obtain a third solution;

[0070] (4) dissolving 0.8 g of γ-polyglutamic acid in 400 mL of distilled water at 550 r / min until completely dissolved to obtain a fourth solution;

[0071] (5) Under stirring in a 45°C water bath, add 300 μL of liquid paraffin to 40.0 mL of the first solution and stir for 30 min.

[0072] (6) Add 200 μL of a mixed solution of Tween 80 and Span 80 (volume ratio 1:1) and emulsify for 30 min to obtain the fifth solution;

[0073] (7) Weigh 13.2 mg of tebuconazole original drug and dissolve it in 500 μL of dimethyl sulfoxide solution. After ultrasonic oscillation for 1 min, add it to the fifth solution and react for 30 min.

[0074] (8) Add 12.0 mL of the third solution dropwise using a peristaltic pump and react for 1 h to obtain the sixth solution;

[0075] (9) Using a peristaltic pump, 40.0 mL of the second solution was added dropwise to the sixth solution and reacted for 1.5 h to obtain the seventh solution;

[0076] (10) Using a peristaltic pump, 40.0 mL of the fourth solution was added to the seventh solution and reacted for 1.5 h to obtain the final chitosan-based liquid fertilizer.

[0077] Chitosan-based liquid fertilizer needs to be diluted when applied, and the volume ratio of chitosan to water is 1:10. It is used for root irrigation at the roots of wheat plants, with 150 mL applied to each plant.

[0078] Comparative Example 2

[0079] During the growth process of wheat, chitosan-based liquid fertilizer was applied in mid-to-late September, late February, early March, mid-March, mid-April, late April, early May, mid-May, and late May.

[0080] Chitosan-based liquid fertilizer is prepared according to the following steps:

[0081] (1) 400 μL of acetic acid solution was added to 39.60 mL of distilled water, and 120 mg of chitosan was slowly added at 550 r / min to completely dissolve the chitosan, followed by ultrasonic oscillation for 2 h (ultrasonic frequency: 40 kHz) to obtain the first solution;

[0082] (2) adding 160 mg of carboxymethyl chitosan into 40.0 mL of distilled water at 550 r / min to completely dissolve the carboxymethyl chitosan to obtain a second solution;

[0083] (3) dissolving 200 μL of 50% glutaraldehyde in 19.80 mL of distilled water to obtain a third solution;

[0084] (4) dissolving 0.8 g of γ-polyglutamic acid in 400 mL of distilled water at 550 r / min until completely dissolved to obtain a fourth solution;

[0085] (5) Under stirring in a 30°C water bath, add 300 μL of liquid paraffin to 40.0 mL of the first solution and stir for 30 min.

[0086] (6) Add 200 μL of a mixed solution of Tween 80 and Span 80 (volume ratio 1:1) and emulsify for 30 min to obtain the fifth solution;

[0087] (7) Weigh 13.2 mg of tebuconazole original drug and dissolve it in 500 μL of dimethyl sulfoxide solution. After ultrasonic oscillation for 1 min, add it to the fifth solution and react for 30 min.

[0088] (8) Add 12.0 mL of the third solution dropwise using a peristaltic pump and react for 1 h to obtain the sixth solution;

[0089] (9) Using a peristaltic pump, 40.0 mL of the second solution was added dropwise to the sixth solution and reacted for 1.5 h to obtain the seventh solution;

[0090] (10) Using a peristaltic pump, 40.0 mL of the fourth solution was added to the seventh solution and reacted for 1.5 h to obtain the final chitosan-based liquid fertilizer.

[0091] Chitosan-based liquid fertilizer needs to be diluted when applied, and the volume ratio of chitosan to water is 1:10. It is used for root irrigation at the roots of wheat plants, with 150 mL applied to each plant.

[0092] Comparative Example 3

[0093] During the growth of wheat, 150 mL of a mixed solution of commercial tebuconazole and nitrogen fertilizer was applied to the roots of wheat in mid-to-late September, late February, early March, mid-March, mid-April, late April, early May, mid-May, and late May.

[0094] Comparative Example 4

[0095] In this comparative example, no treatment was performed during the wheat growth process.

[0096] The wheat field was divided into 4 areas, each area had 60 wheat plants, and the wheat plants were managed according to the methods of Example 1, Example 2, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4, respectively.

[0097] The incidence rate and disease index of wheat in each embodiment and comparative example were investigated, and the results are shown in the following table:

[0098] Incidence rate = total number of diseased plants / total number of investigated plants × 100%

[0099] Disease index = 100 × Σ (number of diseased plants at each level × relative level value) / (total number of plants surveyed × highest level)

[0100] Grading standard: Grade 0, no lesions; Grade 1, lesion area accounts for less than 5% of the total leaf area; Grade 3, lesion area accounts for 6%-15% of the total leaf area; Grade 5, lesion area accounts for 16%-25% of the total leaf area; Grade 7, lesion area accounts for 26%-50% of the total leaf area; Grade 9, lesion area accounts for more than 50% of the total leaf area.

[0101] deal with Incidence Disease index Disease classification Example 1 13.33％ 3.70 light Example 2 11.67％ 2.04 light Comparative Example 1 46.67％ 40.58 Heavy Comparative Example 2 52.33％ 50.35 Heavy Comparative Example 3 58.33％ 56.48 Heavy Comparative Example 4 96.67％ 96.67 Heavy

[0102] It can be seen that the chitosan-based liquid fertilizer prepared by the present invention significantly reduces the incidence rate and disease index of wheat plants. The bactericidal active ingredient in Example 2 is higher than that in Example 1, so the incidence rate is reduced; in Comparative Example 1, the cross-linking substance is sodium tripolyphosphate, and the prepared liquid fertilizer product has precipitation, not a uniform suspension, and the prepared product is unsuccessful, so the incidence rate is significantly increased compared with Example 1; in Comparative Example 2, the experimental temperature is 30°C, and the prepared fertilizer particles are not Figure 1 The spherical shape shown does not extend the effective period, so the incidence rate is significantly higher than that of Example 1; in Comparative Example 3, the bactericidal substance is only a bactericide, and the incidence rate is significantly increased, which may be because the active ingredient of the bactericide is released faster, and the present invention improves the control effect of the bactericide by loading the bactericide with nanomaterials and can extend its effective period; while in Comparative Example 4, there is no treatment, and the incidence rate is significantly increased. It can be seen that in the prevention and control process of the present invention, the role of nano bactericides and γ-polyglutamic acid can effectively reduce the incidence rate of wheat plants.

[0103] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A chitosan-based liquid fertilizer, characterized in that: The chitosan-based liquid fertilizer comprises the following components based on the total weight of the liquid fertilizer: 1.2 parts of chitosan, 1.6 parts of carboxymethyl chitosan, 4-16 parts of gamma-polyglutamic acid, 0.086-0.284 parts of bactericidal active ingredients, 2 parts of glutaraldehyde, 3 parts of liquid paraffin, 0.5-1.5 parts of Tween, 0.5-1.5 parts of Span, and 1300-1500 parts of water.

2. The chitosan-based liquid fertilizer according to claim 1, characterized in that The bactericidal active ingredient is one of benomyl, tebuconazole and fludioxonil.

3. A method for preparing a chitosan-based liquid medicinal fertilizer as claimed in claim 1, characterized in that: The method specifically comprises the following steps: Step 1, using chitosan-based nanomaterials as carriers and bactericidal active ingredients as loads to prepare nano bactericides; Step 2: using γ-polyglutamic acid to encapsulate the nano bactericide to obtain the chitosan-based liquid fertilizer.

4. The method for preparing the chitosan-based liquid medicinal fertilizer according to claim 3, characterized in that: The preparation of the chitosan-based nanomaterial is as follows: Liquid paraffin is dripped into the chitosan solution, and then a certain amount of glutaraldehyde solution is added. After a period of reaction, carboxymethyl chitosan solution is added, and chitosan-based nanomaterials are obtained after cross-linking.

5. The method for preparing the chitosan-based liquid medicinal fertilizer according to claim 4, characterized in that: The volume ratio of the γ-polyglutamic acid solution to the chitosan solution is 1:1-2:1, the volume ratio of the chitosan solution to the carboxymethyl chitosan solution is 1:1, and the concentration of the γ-polyglutamic acid solution is 1-4 g / L.

6. The method for preparing the chitosan-based liquid medicinal fertilizer according to claim 4, characterized in that: The bactericidal active ingredient is added after glutaraldehyde is added and reacted for a period of time, and Tween 80 and Span 80 are added for emulsification before the glutaraldehyde solution is added.

7. The method for preparing the chitosan-based liquid medicinal fertilizer according to claim 6, characterized in that: The reaction system required conditions are a water bath at 45°C and continuous stirring.

8. The method for preparing the chitosan-based liquid medicinal fertilizer according to claim 6, characterized in that: The volume ratio of Tween 80 to Span 80 is 1:1-1:2.

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