Disease-resistant water-soluble fertilizer and preparation method thereof

Abstract

The invention discloses a disease-resistant water-soluble fertilizer and a preparation method thereof, belonging to the technical field of water-soluble fertilizers. The preparation method comprises: preparing first nanoparticles, preparing second nanoparticles, dissolving, suspending and mixing; the preparation of the first nanoparticles comprises the following steps: preparing a chitosan aqueous solution, acid treatment, adsorption, cross-linking, fixing zinc ions and chelation; the preparation of the second nanoparticles comprises the following steps: activation, grafting and coating; the suspension comprises mixing the first nanoparticles, the second nanoparticles and water, stirring at 60-65 DEG C, adding potassium humate, potassium L-glutamate and polyvinyl pyrrolidone, and continuing to stir; the disease-resistant water-soluble fertilizer prepared by the invention has good appearance, storage resistance and dilution effect, fast dilution speed, is not prone to flatulence when stored at high temperature, does not need frequent fertilization, and can improve the growth rate and yield of crops while improving the disease resistance of crops.

Description

Technical Field

[0001] The invention relates to the technical field of water-soluble fertilizers, and in particular to a disease-resistant water-soluble fertilizer and a preparation method thereof. Background Art

[0002] Water-soluble fertilizer is a multi-component compound fertilizer that can be completely and quickly dissolved in water. The main functions of water-soluble fertilizer include providing nutrition for crops, improving the disease resistance of crops, increasing crop yields, and improving the quality of agricultural products. Compared with traditional superphosphate and granulated compound fertilizers, water-soluble fertilizers have the advantages of small dosage, convenient use, low cost, fast crop absorption, and high fertilizer utilization rate. In addition, they can be applied to facility agriculture such as sprinkler and drip irrigation to achieve water-fertilizer integration and achieve the effect of saving water, fertilizer, and labor.

[0003] Commonly used water-soluble fertilizers mainly include solid water-soluble fertilizers and liquid water-soluble fertilizers. The preparation methods of solid water-soluble fertilizers mainly include physical mixing and chemical synthesis. Among them, the physical mixing method specifically includes mixing a variety of water-soluble nutrients and then performing crushing, stirring, screening and other steps to finally obtain solid water-soluble fertilizers; the chemical synthesis method specifically includes mixing nutrients and chelating agents under certain reaction conditions and then performing dissolution, chelation, concentration, drying and other steps to finally obtain solid water-soluble fertilizers. The preparation method of liquid water-soluble fertilizers specifically includes mixing nutrients, chelating agents, and additives and then performing dissolution, suspension, mixing and other steps to finally obtain liquid water-soluble fertilizers. The liquid water-soluble fertilizers currently prepared are mainly concentrated liquid water-soluble fertilizers, which need to be diluted before use. Compared with solid water-soluble fertilizers, liquid water-soluble fertilizers do not need to be dissolved before use, have a fast dilution speed, and are easy to use. In addition, since the additives used in the preparation of liquid water-soluble fertilizers include surfactants, the surfactants can form a thin film on the surface of crops, increasing the contact area between crops and nutrients, further improving the utilization rate of fertilizer. Therefore, the most commonly used water-soluble fertilizers are liquid water-soluble fertilizers.

[0004] However, the following problems exist in the use of liquid water-soluble fertilizers: First, since liquid water-soluble fertilizers are mainly concentrated liquid water-soluble fertilizers, the nutrients are in an oversaturated state and are prone to crystallization during storage, further affecting the storage resistance of the liquid water-soluble fertilizers; Second, in order to increase the nitrogen content of the water-soluble fertilizers, urea is usually added during preparation. Urea is easily hydrolyzed at high temperatures, resulting in the prepared liquid water-soluble fertilizers being prone to flatulence when stored at high temperatures; Third, with the increasing number and severity of plant diseases, enhancing plant disease resistance has become a global problem. Therefore, disease-resistant water-soluble fertilizers have gradually become the current research and development focus. In order to improve the disease resistance of crops, the most commonly used method is to add chelated trace elements and water-soluble organic matter to the water-soluble fertilizers at the same time, but water is lost and it is difficult to preserve them in the soil for a long time. In order to improve the disease resistance effect, frequent fertilization is required, resulting in a large waste of nutrients.

[0005] In order to solve the above problems, the commonly used solutions are: first, adding water-soluble nanoparticles. On the one hand, water-soluble nanoparticles can play an emulsifying role, thereby avoiding the stratification and crystallization problems of liquid water-soluble fertilizers during storage, and improving the fluidity of liquid water-soluble fertilizers. On the other hand, water-soluble nanoparticles can play a role in fixing nutrients, thereby avoiding the loss of nutrients and further avoiding frequent fertilization; second, reducing the amount of urea used to avoid the occurrence of flatulence.

[0006] However, during the experiment, it was found that when preparing water-soluble nanoparticles, the most commonly used method is to use a surfactant to enrich the nanoparticles with hydroxyls. However, the surfactant generally forms hydrogen bonds with the hydroxyl groups on the surface of the nanoparticles and is coated on the surface of the nanoparticles. The hydrogen bonding effect is weak. When preparing liquid water-soluble fertilizers, the temperature is high, and the hydrogen bonding effect is further weakened. The surfactant is easily detached from the surface of the nanoparticles, resulting in reduced water solubility and poor dispersibility of the water-soluble nanoparticles, which further affects the appearance, storage resistance, and dilution rate of the liquid water-soluble fertilizer. It also affects the dilution effect of the liquid water-soluble fertilizer, which is specifically manifested in the presence of precipitation in the liquid water-soluble fertilizer after dilution. In addition, reducing the amount of urea used will lead to a decrease in the nitrogen content of the liquid water-soluble fertilizer, affecting the growth rate and yield of crops. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention provides a disease-resistant water-soluble fertilizer and a preparation method thereof. The prepared disease-resistant water-soluble fertilizer has good appearance, storage resistance, and dilution effect, and has a fast dilution speed. It is not easy to cause flatulence when stored at high temperatures, and does not require frequent fertilization. While improving the disease resistance of crops, it can also increase the growth rate and yield of crops.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0009] A method for preparing a disease-resistant water-soluble fertilizer comprises the following steps: preparing first nanoparticles, preparing second nanoparticles, dissolving, suspending, and mixing;

[0010] The preparation of the first nanoparticles comprises the following steps: preparing a chitosan aqueous solution, acid treatment, adsorption, cross-linking, fixing zinc ions, and chelation;

[0011] The chitosan aqueous solution is prepared by mixing chitosan and acetic acid aqueous solution, and stirring at room temperature at a stirring speed of 300-400 rpm for 30-40 minutes to obtain a chitosan aqueous solution;

[0012] In the preparation of the chitosan aqueous solution, the mass volume ratio of chitosan to acetic acid aqueous solution is 18-20g:1000-1100mL;

[0013] The mass fraction of the acetic acid aqueous solution is 2-2.5%;

[0014] The weight average molecular weight of the chitosan is 150,000, and the degree of deacetylation is 90%;

[0015] The acid treatment comprises mixing the nano-diatomaceous earth and the hydrochloric acid aqueous solution, stirring at a stirring speed of 300-400 rpm for 30-40 minutes at room temperature, centrifuging, washing the precipitate with water, and drying to obtain the acid-treated diatomaceous earth;

[0016] In the acid treatment, the mass volume ratio of nano-diatomaceous earth and hydrochloric acid aqueous solution is 24-25g:250-300mL;

[0017] The mass fraction of the hydrochloric acid aqueous solution is 5%;

[0018] The average particle size of the nano diatomite is 100 nm;

[0019] The adsorption comprises mixing the acid-treated diatomaceous earth and the chitosan aqueous solution, stirring at room temperature at a stirring speed of 100-200 rpm for 3-3.5 hours, centrifuging, washing the precipitate with water, and drying to obtain the adsorbed diatomaceous earth;

[0020] In the adsorption, the mass volume ratio of the acid-treated diatomaceous earth and the chitosan aqueous solution is 20-21 g: 1800-2000 mL;

[0021] The cross-linking comprises mixing the adsorbed diatomaceous earth and water, stirring at 35-40° C. and 100-200 rpm for 50-60 min, adding glutaraldehyde aqueous solution, stirring for 2.5-3 h after the addition is completed, centrifuging, washing the precipitate with water, and drying to obtain the cross-linked diatomaceous earth;

[0022] In the cross-linking, the mass volume ratio of the adsorbed diatomaceous earth, water, and glutaraldehyde aqueous solution is 45-48 g: 1000-1200 mL: 170-180 mL;

[0023] The mass concentration of the glutaraldehyde aqueous solution is 20%;

[0024] The addition rate of the glutaraldehyde aqueous solution is 10-12 mL / min;

[0025] The zinc ion is fixed by mixing the cross-linked diatomaceous earth and the zinc chloride aqueous solution, stirring at room temperature at a stirring speed of 50-100 rpm for 20-30 min, adding a hydrochloric acid aqueous solution, continuing to stir for 1.5-2 h, centrifuging, washing the precipitate with water, and drying to obtain the diatomaceous earth with fixed zinc ions;

[0026] In the fixed zinc ion, the mass volume ratio of the cross-linked diatomaceous earth, the zinc chloride aqueous solution, and the hydrochloric acid aqueous solution is 47-50 g: 1400-1500 mL: 2-3 mL;

[0027] The mass fraction of the zinc chloride aqueous solution is 5%;

[0028] The mass fraction of the hydrochloric acid aqueous solution is 5%;

[0029] The chelation comprises mixing the diatomaceous earth with fixed zinc ions and the aqueous solution of polyvinyl alcohol 1788, stirring at room temperature at a stirring speed of 50-100 rpm for 20-30 minutes, adding the aqueous solution of hydrochloric acid, continuing to stir for 3-3.5 hours, centrifuging, washing the precipitate with water, and drying to obtain the first nanoparticles;

[0030] In the chelation, the mass volume ratio of the diatomaceous earth after the zinc ions are fixed, the polyvinyl alcohol 1788 aqueous solution, and the hydrochloric acid aqueous solution is 45-46g:3100-3300mL:6-7mL;

[0031] The mass fraction of the polyvinyl alcohol 1788 aqueous solution is 10%;

[0032] The mass fraction of the hydrochloric acid aqueous solution is 5%;

[0033] The preparation of the second nanoparticles comprises the following steps: activation, grafting, and coating;

[0034] The activation comprises mixing the nano-activated carbon and concentrated hydrochloric acid, stirring at room temperature at a stirring speed of 100-200 rpm for 8-9 hours, centrifuging, washing the precipitate with water, and drying to obtain activated activated carbon;

[0035] In the activation, the mass volume ratio of nano-activated carbon and concentrated hydrochloric acid is 42-45g:270-300mL;

[0036] The mass fraction of concentrated hydrochloric acid is 37%;

[0037] The average particle size of the nano activated carbon is 100 nm;

[0038] The grafting comprises mixing the activated activated carbon, epichlorohydrin and N,N-dimethylacetamide, stirring at 80-85°C and 100-200 rpm for 50-60 minutes, adding ethylenediamine, stirring for 50-60 minutes after the addition, adding triethylamine, stirring for 50-60 minutes, centrifuging, washing the precipitate with anhydrous ethanol and water in turn, and drying to obtain the grafted activated carbon;

[0039] In the grafting, the mass volume ratio of activated carbon, epichlorohydrin, N,N-dimethylacetamide, ethylenediamine and triethylamine is 56-60g:140-150mL:140-160mL:60-70mL:140-150mL;

[0040] The addition rate of the ethylenediamine is 3-4 mL / min;

[0041] The coating comprises mixing the grafted activated carbon and the polyvinyl pyrrolidone K30 aqueous solution, stirring at room temperature at a stirring speed of 100-200 rpm for 50-60 minutes, centrifuging, washing the precipitate with water, and drying to obtain the second nanoparticles;

[0042] In the coating, the mass volume ratio of the grafted activated carbon and the polyvinyl pyrrolidone K30 aqueous solution is 58-60g:900-1000mL;

[0043] The mass fraction of the polyvinyl pyrrolidone K30 aqueous solution is 5%;

[0044] The dissolution comprises mixing dipotassium hydrogen phosphate, potassium dihydrogen phosphate and water, stirring at 70-75° C. at a stirring speed of 200-300 rpm for 20-30 min, adding potassium sulfate and potassium nitrate, continuing stirring for 20-30 min, cooling to room temperature, adding urea, continuing stirring for 30-40 min after the addition is completed, adding EDTA-Ca, EDTA-Mg, EDTA-Zn and EDTA-Fe, and continuing stirring for 30-40 min to obtain a dissolved solution;

[0045] In the dissolution, the mass volume ratio of dipotassium hydrogen phosphate, potassium dihydrogen phosphate, water, potassium sulfate, potassium nitrate, urea, EDTA-Ca, EDTA-Mg, EDTA-Zn, and EDTA-Fe is 16-18 g: 7-8 g: 60-70 mL: 30-32 g: 5-6 g: 45-50 g: 4-5 g: 2-3 g: 2-2.5 g: 1-1.3 g;

[0046] The urea addition rate is 4-5 g / min;

[0047] The suspension comprises mixing the first nanoparticles, the second nanoparticles and water, stirring at 60-65° C. and a stirring speed of 200-300 rpm for 20-30 min, adding potassium humate, potassium L-glutamate and polyvinyl pyrrolidone, and continuing stirring for 30-40 min to obtain a suspension;

[0048] In the suspension, the mass volume ratio of the first nanoparticle, the second nanoparticle, water, potassium humate, potassium L-glutamate, and polyvinyl pyrrolidone is 16-17 g: 5-5.5 g: 60-70 mL: 11-13 g: 2-2.5 g: 1.5-1.8 g;

[0049] The mixing is performed, stirring the suspension at a stirring speed of 200-300 rpm at room temperature, and the dissolved solution is added to the suspension, and stirring is continued for 50-60 minutes after the addition is completed to obtain a disease-resistant water-soluble fertilizer;

[0050] In the mixing, the mass ratio of the first nanoparticles in the suspension to the dipotassium hydrogen phosphate in the dissolving solution is 16-17:16-18;

[0051] The addition rate of the dissolving solution is 5-6 mL / min.

[0052] A disease-resistant water-soluble fertilizer prepared by the above-mentioned preparation method.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] (1) The method for preparing the disease-resistant water-soluble fertilizer of the present invention comprises adding a first nanoparticle and a second nanoparticle during the preparation process. The method for preparing the first nanoparticle comprises preparing a chitosan aqueous solution, acid treatment, adsorption, crosslinking, fixing zinc ions, and chelation. The preparation of the chitosan aqueous solution comprises dissolving chitosan in an acetic acid aqueous solution, the acid treatment comprises using a hydrochloric acid aqueous solution to remove impurities and activate nano-diatomite, the adsorption comprises using the acid-treated nano-diatomite to adsorb chitosan in the chitosan aqueous solution, the crosslinking comprises using glutaraldehyde to crosslink the nano-diatomite that adsorbs chitosan, thereby forming a firm cross-linked chitosan coating layer on the surface of the nano-diatomite, and the fixing of zinc ions comprises adding the nano-diatomite having a cross-linked chitosan coating layer on the surface to the nano-diatomite. In the zinc chloride aqueous solution, the surface of the cross-linked chitosan coating layer binds zinc ions through coordination, and the nano diatomaceous earth that binds zinc ions is added to the polyvinyl alcohol aqueous solution by chelation. The polyvinyl alcohol and chitosan coordinate with the zinc ions at the same time, and a chelation ring can be formed between the polyvinyl alcohol and the chitosan, thereby improving the binding force of the polyvinyl alcohol on the surface of the first nanoparticle, ensuring the dispersibility of the first nanoparticle, and further improving the appearance, storage resistance, dilution effect, and dilution speed of the prepared disease-resistant water-soluble fertilizer. In the use of the disease-resistant water-soluble fertilizer, the first nanoparticle can play a role in fixing nutrients and avoiding the loss of nutrients. The chitosan and zinc ions in the first nanoparticle can also be combined with the soil or crop surface to play a continuous role. The invention discloses a method for preparing the nanoparticles, which comprises activation, grafting and coating. The activation comprises surface treatment of activated carbon with concentrated hydrochloric acid, thereby introducing a large number of hydroxyl groups on the surface of the activated carbon. The grafting comprises mixing the activated carbon with epichlorohydrin, wherein the epichlorohydrin reacts with the hydroxyl groups on the surface of the activated carbon to introduce an exocyclic ether bond containing an epoxy group, and then successively adding ethylenediamine and triethylamine to react with the exocyclic ether bond containing an epoxy group to introduce a primary amino group and a quaternary amino group. The quaternary amino group is alkaline. The coating comprises adding the grafted activated carbon to an aqueous solution of polyvinyl pyrrolidone, wherein the polyvinyl pyrrolidone is reacted with the epichlorohydrin to react with the hydroxyl groups on the surface of the activated carbon to introduce an exocyclic ether bond containing an epoxy group. Vinyl pyrrolidone forms hydrogen bonds with primary amino groups, thereby combining polyvinyl pyrrolidone with the surface of the second nanoparticles, improving the dispersibility of the second nanoparticles and the fluidity of the second nanoparticles, which helps the second nanoparticles to disperse quickly. The second nanoparticles can absorb carbon dioxide generated by urea hydrolysis, and the quaternary amino groups in the second nanoparticles can neutralize carbon dioxide, thereby avoiding the generation of flatulence. In addition, the primary amino groups and quaternary amino groups can also play a role in fixing nutrients and promoting plant absorption, thereby ensuring that the prepared disease-resistant water-soluble fertilizer is not prone to flatulence when stored at high temperatures, and also ensuring that frequent fertilization is not required, thereby improving the disease resistance of crops while increasing the growth rate and yield of crops;

[0055] (2) The method for preparing the disease-resistant water-soluble fertilizer of the present invention has a good appearance, is a uniform liquid, and has no precipitation;

[0056] (3) The method for preparing the disease-resistant water-soluble fertilizer of the present invention has good storage stability. The disease-resistant water-soluble fertilizer prepared by the present invention is sealed and stored in an environment of 25° C. for 100 days, and it is still a uniform liquid without precipitation and flatulence.

[0057] (4) The method for preparing the disease-resistant water-soluble fertilizer of the present invention is that the prepared disease-resistant water-soluble fertilizer is not prone to flatulence when stored at high temperature. The disease-resistant water-soluble fertilizer prepared by the present invention is sealed and stored in an environment of 60° C. for 1 day, and it is still a uniform liquid without precipitation and flatulence;

[0058] (5) The method for preparing the disease-resistant water-soluble fertilizer of the present invention has good dilution effect and fast dilution speed. 100 mL of the disease-resistant water-soluble fertilizer prepared by the present invention is slowly added into 40 L of water, and the adding time is controlled to be 1 min. During the adding process, the water is stirred at a stirring speed of 50 rpm. After the adding is completed, the stirring is continued for 2 min. The liquid water-soluble fertilizer can be completely dissolved without precipitation.

[0059] (6) The method for preparing the disease-resistant water-soluble fertilizer of the present invention can improve the disease resistance of crops and the growth rate and yield of crops without frequent fertilization. The disease-resistant water-soluble fertilizer prepared by the present invention is used for wheat planting. It is sprayed once at the jointing stage, booting stage and filling stage of wheat respectively. The start time of the wheat maturity period can be advanced from June 15 to June 2 or June 3, and the yield can be increased from 38.1kg / 50m 2 Increased to 41.0-41.3kg / 50m 2 The control effect on powdery mildew can reach 62.4-63.7%, and the control effect on sheath blight can reach 53.8-54.5%. DETAILED DESCRIPTION

[0060] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described.

[0061] Example 1

[0062] A method for preparing a disease-resistant water-soluble fertilizer, specifically comprising:

[0063] 1. Preparation of the first nanoparticles:

[0064] (1) Preparation of chitosan aqueous solution: 18 g of chitosan and 1000 mL of 2% acetic acid aqueous solution were mixed, and the mixture was stirred at 300 rpm for 30 min at room temperature to obtain a chitosan aqueous solution;

[0065] The weight average molecular weight of the chitosan is 150,000, and the degree of deacetylation is 90%;

[0066] (2) Acid treatment: 24 g of nano-diatomaceous earth and 250 mL of a 5% hydrochloric acid aqueous solution were mixed, stirred at 300 rpm for 30 min at room temperature, centrifuged, the precipitate was washed with water, and dried to obtain acid-treated diatomaceous earth;

[0067] The average particle size of the nano diatomite is 100 nm;

[0068] (3) Adsorption: 20 g of acid-treated diatomaceous earth and 1800 mL of chitosan aqueous solution were mixed, stirred at room temperature at a stirring speed of 100 rpm for 3 h, centrifuged, the precipitate was washed with water, and dried to obtain the adsorbed diatomaceous earth;

[0069] (4) Cross-linking: 45 g of adsorbed diatomaceous earth and 1000 mL of water were mixed, and the mixture was stirred at 35 °C at a stirring speed of 100 rpm for 50 min. 170 mL of 20% glutaraldehyde aqueous solution was slowly added at a rate of 10 mL / min. After the addition was completed, stirring was continued for 2.5 h. The mixture was centrifuged, the precipitate was washed with water, and dried to obtain cross-linked diatomaceous earth.

[0070] (5) Fixing zinc ions: 47 g of cross-linked diatomaceous earth and 1400 mL of a 5% zinc chloride aqueous solution were mixed, stirred at room temperature at a stirring speed of 50 rpm for 20 min, 2 mL of a 5% hydrochloric acid aqueous solution was added, and stirring was continued for 1.5 h. The mixture was centrifuged, the precipitate was washed with water, and dried to obtain diatomaceous earth with fixed zinc ions.

[0071] (6) Chelation: 45 g of diatomaceous earth with fixed zinc ions and 3100 mL of a 10% aqueous solution of polyvinyl alcohol 1788 were mixed, stirred at 50 rpm for 20 min at room temperature, 6 mL of a 5% aqueous solution of hydrochloric acid was added, and stirring was continued for 3 h. The mixture was centrifuged, and the precipitate was washed with water and dried to obtain the first nanoparticles.

[0072] 2. Preparation of the second nanoparticles:

[0073] (1) Activation: 42 g of nano-activated carbon and 270 mL of 37% concentrated hydrochloric acid were mixed, stirred at room temperature at a stirring speed of 100 rpm for 8 h, centrifuged, washed with water, and dried to obtain activated activated carbon;

[0074] The average particle size of the nano activated carbon is 100 nm;

[0075] (2) Grafting: 56 g of activated activated carbon, 140 mL of epichlorohydrin, and 140 mL of N,N-dimethylacetamide were mixed, and stirred at 80 °C at a stirring speed of 100 rpm for 50 min. 60 mL of ethylenediamine was slowly added at a rate of 3 mL / min. After the addition was completed, stirring was continued for 50 min. 140 mL of triethylamine was added and stirring was continued for 50 min. The mixture was centrifuged, and the precipitate was washed with anhydrous ethanol and water in turn, and dried to obtain the grafted activated carbon.

[0076] (3) Coating: 58 g of the grafted activated carbon and 900 mL of a 5% by mass polyvinyl pyrrolidone K30 aqueous solution were mixed, stirred at room temperature at a stirring speed of 100 rpm for 50 min, centrifuged, washed with water, and dried to obtain second nanoparticles;

[0077] 3. Dissolution: Mix 16g of dipotassium hydrogen phosphate, 7g of potassium dihydrogen phosphate, and 60mL of water, stir at 70°C at a stirring speed of 200rpm for 20min, add 30g of potassium sulfate and 5g of potassium nitrate, continue stirring for 20min, cool to room temperature, slowly add 45g of urea, control the addition rate to 4g / min, continue stirring for 30min after the addition is completed, add 4g of EDTA-Ca, 2g of EDTA-Mg, 2g of EDTA-Zn, and 1g of EDTA-Fe, continue stirring for 30min to obtain a dissolved solution;

[0078] 4. Suspension: 16 g of the first nanoparticles, 5 g of the second nanoparticles, and 60 mL of water were mixed, and the mixture was stirred at 60° C. and 200 rpm for 20 min. 11 g of potassium humate, 2 g of potassium L-glutamate, and 1.5 g of polyvinyl pyrrolidone were added, and the mixture was stirred for 30 min to obtain a suspension.

[0079] 5. Mixing: Stir the entire suspension obtained by suspending in step 4 at a stirring speed of 200 rpm at room temperature, and slowly add the entire solution obtained by dissolving in step 3 to the entire suspension obtained by suspending in step 4, controlling the adding speed to 5 mL / min. After the addition is completed, continue stirring for 50 minutes to obtain a disease-resistant water-soluble fertilizer.

[0080] This embodiment also provides a disease-resistant water-soluble fertilizer prepared by the aforementioned preparation method.

[0081] Example 2

[0082] A method for preparing a disease-resistant water-soluble fertilizer, specifically comprising:

[0083] 1. Preparation of the first nanoparticles:

[0084] (1) Preparation of chitosan aqueous solution: 19 g of chitosan and 1050 mL of 2.2% acetic acid aqueous solution were mixed, and the mixture was stirred at 350 rpm for 35 min at room temperature to obtain a chitosan aqueous solution;

[0085] The weight average molecular weight of the chitosan is 150,000, and the degree of deacetylation is 90%;

[0086] (2) Acid treatment: 24.5 g of nano-diatomaceous earth and 280 mL of a 5% hydrochloric acid aqueous solution were mixed, stirred at room temperature at a stirring speed of 350 rpm for 35 min, centrifuged, the precipitate was washed with water, and dried to obtain acid-treated diatomaceous earth;

[0087] The average particle size of the nano diatomite is 100 nm;

[0088] (3) Adsorption: 20.5 g of acid-treated diatomaceous earth and 1900 mL of chitosan aqueous solution were mixed, stirred at room temperature at a stirring speed of 150 rpm for 3.5 h, centrifuged, the precipitate was washed with water, and dried to obtain the adsorbed diatomaceous earth;

[0089] (4) Cross-linking: 46 g of adsorbed diatomaceous earth and 1100 mL of water were mixed, and the mixture was stirred at 38 °C at a stirring speed of 150 rpm for 55 min. 175 mL of 20% glutaraldehyde aqueous solution was slowly added at a rate of 11 mL / min. After the addition was completed, stirring was continued for 3 h, and the mixture was centrifuged. The precipitate was washed with water and dried to obtain cross-linked diatomaceous earth.

[0090] (5) Fixing zinc ions: 48 g of cross-linked diatomaceous earth and 1450 mL of a 5% zinc chloride aqueous solution were mixed, stirred at room temperature at a stirring speed of 80 rpm for 25 min, 3 mL of a 5% hydrochloric acid aqueous solution was added, and stirring was continued for 2 h. The mixture was centrifuged, the precipitate was washed with water, and dried to obtain diatomaceous earth with fixed zinc ions.

[0091] (6) Chelation: 45.5 g of diatomaceous earth with fixed zinc ions and 3200 mL of a 10% aqueous solution of polyvinyl alcohol 1788 were mixed, stirred at 80 rpm for 25 min at room temperature, 6.5 mL of a 5% aqueous solution of hydrochloric acid was added, and stirring was continued for 3.5 h. The mixture was centrifuged, and the precipitate was washed with water and dried to obtain the first nanoparticles.

[0092] 2. Preparation of the second nanoparticles:

[0093] (1) Activation: 44 g of nano-activated carbon and 280 mL of 37% concentrated hydrochloric acid were mixed, stirred at room temperature at a stirring speed of 150 rpm for 8.5 h, centrifuged, washed with water, and dried to obtain activated activated carbon;

[0094] The average particle size of the nano activated carbon is 100 nm;

[0095] (2) Grafting: 58 g of activated activated carbon, 145 mL of epichlorohydrin, and 145 mL of N,N-dimethylacetamide were mixed, and stirred at 82 °C at a stirring speed of 150 rpm for 55 min. 65 mL of ethylenediamine was slowly added at a rate of 3 mL / min. After the addition was completed, stirring was continued for 55 min. 145 mL of triethylamine was added and stirring was continued for 55 min. The mixture was centrifuged, and the precipitate was washed with anhydrous ethanol and water in turn, and dried to obtain the grafted activated carbon.

[0096] (3) Coating: 59 g of the grafted activated carbon and 950 mL of a 5% by mass polyvinyl pyrrolidone K30 aqueous solution were mixed, stirred at room temperature at a stirring speed of 150 rpm for 55 min, centrifuged, washed with water, and dried to obtain second nanoparticles;

[0097] 3. Dissolution: Mix 17g of dipotassium hydrogen phosphate, 7.5g of potassium dihydrogen phosphate, and 65mL of water, stir at 72°C at a stirring speed of 250rpm for 25min, add 31g of potassium sulfate and 5.5g of potassium nitrate, continue stirring for 25min, cool to room temperature, slowly add 48g of urea, control the addition rate to 5g / min, continue stirring for 35min after the addition is completed, add 4.5g of EDTA-Ca, 2.5g of EDTA-Mg, 2.3g of EDTA-Zn, and 1.2g of EDTA-Fe, continue stirring for 35min to obtain a dissolved solution;

[0098] 4. Suspension: 16.5 g of the first nanoparticles, 5.2 g of the second nanoparticles, and 65 mL of water were mixed, and the mixture was stirred at 62° C. and 250 rpm for 25 min. 12 g of potassium humate, 2.3 g of potassium L-glutamate, and 1.6 g of polyvinyl pyrrolidone were added, and the mixture was stirred for 35 min to obtain a suspension.

[0099] 5. Mixing: Stir the entire suspension obtained by suspending in step 4 at a stirring speed of 250 rpm at room temperature, and slowly add the entire solution obtained by dissolving in step 3 to the entire suspension obtained by suspending in step 4, control the addition speed to 5 mL / min, and continue stirring for 55 minutes after the addition is completed to obtain a disease-resistant water-soluble fertilizer.

[0100] This embodiment also provides a disease-resistant water-soluble fertilizer prepared by the aforementioned preparation method.

[0101] Example 3

[0102] A method for preparing a disease-resistant water-soluble fertilizer, specifically comprising:

[0103] 1. Preparation of the first nanoparticles:

[0104] (1) Preparation of chitosan aqueous solution: 20 g of chitosan and 1100 mL of 2.5% acetic acid aqueous solution were mixed, and the mixture was stirred at 400 rpm for 40 min at room temperature to obtain a chitosan aqueous solution;

[0105] The weight average molecular weight of the chitosan is 150,000, and the degree of deacetylation is 90%;

[0106] (2) Acid treatment: 25 g of nano-diatomaceous earth and 300 mL of a 5% hydrochloric acid aqueous solution were mixed, stirred at 400 rpm for 40 min at room temperature, centrifuged, the precipitate was washed with water, and dried to obtain acid-treated diatomaceous earth;

[0107] The average particle size of the nano diatomite is 100 nm;

[0108] (3) Adsorption: 21 g of acid-treated diatomaceous earth and 2000 mL of chitosan aqueous solution were mixed, stirred at room temperature at a stirring speed of 200 rpm for 3.5 h, centrifuged, the precipitate was washed with water, and dried to obtain the adsorbed diatomaceous earth;

[0109] (4) Cross-linking: 48 g of adsorbed diatomaceous earth and 1200 mL of water were mixed, and the mixture was stirred at 200 rpm for 60 min at 40 °C. 180 mL of 20% glutaraldehyde aqueous solution was slowly added at a rate of 12 mL / min. After the addition was completed, the mixture was stirred for 3 h, centrifuged, and the precipitate was washed with water and dried to obtain cross-linked diatomaceous earth.

[0110] (5) Fixing zinc ions: 50 g of cross-linked diatomaceous earth and 1500 mL of a 5% zinc chloride aqueous solution were mixed, stirred at room temperature at a stirring speed of 100 rpm for 30 min, 3 mL of a 5% hydrochloric acid aqueous solution was added, and stirring was continued for 2 h. The mixture was centrifuged, the precipitate was washed with water, and dried to obtain diatomaceous earth with fixed zinc ions.

[0111] (6) Chelation: 46 g of diatomaceous earth with fixed zinc ions and 3300 mL of a 10% aqueous solution of polyvinyl alcohol 1788 were mixed, and the mixture was stirred at 100 rpm for 30 min at room temperature. 7 mL of a 5% aqueous solution of hydrochloric acid was added, and the mixture was stirred for 3.5 h. The mixture was centrifuged, and the precipitate was washed with water and dried to obtain the first nanoparticles.

[0112] 2. Preparation of the second nanoparticles:

[0113] (1) Activation: 45 g of nano-activated carbon and 300 mL of 37% concentrated hydrochloric acid were mixed, stirred at room temperature at a stirring speed of 200 rpm for 9 h, centrifuged, washed with water, and dried to obtain activated activated carbon;

[0114] The average particle size of the nano activated carbon is 100 nm;

[0115] (2) Grafting: 60 g of activated activated carbon, 150 mL of epichlorohydrin, and 160 mL of N,N-dimethylacetamide were mixed, and stirred at 85 °C at a stirring speed of 200 rpm for 60 min. 70 mL of ethylenediamine was slowly added at a rate of 4 mL / min. After the addition was completed, stirring was continued for 60 min. 150 mL of triethylamine was added and stirring was continued for 60 min. The mixture was centrifuged, and the precipitate was washed with anhydrous ethanol and water in turn, and dried to obtain the grafted activated carbon.

[0116] (3) Coating: 60 g of the grafted activated carbon and 1000 mL of a 5% by mass polyvinyl pyrrolidone K30 aqueous solution were mixed, stirred at room temperature at a stirring speed of 200 rpm for 60 min, centrifuged, washed with water, and dried to obtain second nanoparticles;

[0117] 3. Dissolution: Mix 18g of dipotassium hydrogen phosphate, 8g of potassium dihydrogen phosphate, and 70mL of water, stir at 75°C at a stirring speed of 300rpm for 30min, add 32g of potassium sulfate and 6g of potassium nitrate, continue stirring for 30min, cool to room temperature, slowly add 50g of urea, control the addition rate to 5g / min, continue stirring for 40min after the addition is completed, add 5g of EDTA-Ca, 3g of EDTA-Mg, 2.5g of EDTA-Zn, and 1.3g of EDTA-Fe, continue stirring for 40min to obtain a dissolved solution;

[0118] 4. Suspension: 17 g of the first nanoparticles, 5.5 g of the second nanoparticles, and 70 mL of water were mixed, and stirred at 65°C at a stirring speed of 300 rpm for 30 min, 13 g of potassium humate, 2.5 g of potassium L-glutamate, and 1.8 g of polyvinyl pyrrolidone were added, and stirring was continued for 40 min to obtain a suspension;

[0119] 5. Mixing: Stir the entire suspension obtained by suspending in step 4 at a stirring speed of 300 rpm at room temperature, and slowly add the entire solution obtained by dissolving in step 3 to the entire suspension obtained by suspending in step 4, control the addition speed to 6 mL / min, and continue stirring for 60 minutes after the addition is completed to obtain a disease-resistant water-soluble fertilizer.

[0120] This embodiment also provides a disease-resistant water-soluble fertilizer prepared by the aforementioned preparation method.

[0121] Comparative Example 1

[0122] Based on Example 2, the first step of preparing the first nanoparticles is changed to:

[0123] 24.5 g of nano-diatomaceous earth and 280 mL of a 5% hydrochloric acid aqueous solution were mixed, stirred at a stirring speed of 350 rpm at room temperature for 35 min, centrifuged, the precipitate was washed with water, and dried, and then mixed with 3200 mL of a 10% polyvinyl alcohol 1788 aqueous solution, stirred at a stirring speed of 80 rpm at room temperature for 3.5 h, centrifuged, the precipitate was washed with water, and dried to obtain first nanoparticles;

[0124] The average particle size of the nano diatomaceous earth is 100 nm.

[0125] The remaining operations are the same as those in Example 2.

[0126] Comparative Example 2

[0127] On the basis of Example 2, the preparation of the second nanoparticles in step 2 is omitted, and the addition of the second nanoparticles in step 4, the suspension step, is omitted.

[0128] The remaining operations are the same as those in Example 2.

[0129] Test Example 1

[0130] The appearance of the disease-resistant water-soluble fertilizers prepared in Examples 1-3 and Comparative Examples 1-2 was observed, and the results were as follows:

[0131]

[0132] Test Example 2

[0133] 100 mL of the disease-resistant water-soluble fertilizer prepared in Examples 1-3 and Comparative Examples 1-2 and 5 transparent packaging bottles with a specification of 100 mL were taken respectively, and the disease-resistant water-soluble fertilizers were respectively put into the transparent packaging bottles and sealed, and then stored in an environment of 25° C. for 100 days, and then the presence of flatulence and the appearance were observed. The observation results are as follows:

[0134]

[0135] Test Example 3

[0136] 100 mL of the disease-resistant water-soluble fertilizer prepared in Examples 1-3 and Comparative Examples 1-2 and 5 transparent packaging bottles with a specification of 100 mL were taken respectively, and the disease-resistant water-soluble fertilizers were respectively put into the transparent packaging bottles and sealed, and then stored in an environment of 60° C. for 1 day, and then the presence of flatulence and the appearance were observed. The observation results are as follows:

[0137]

[0138] Test Example 4

[0139] Take 100 mL of the disease-resistant water-soluble fertilizer prepared in Example 1-3 and Comparative Example 1-2 and 5 parts of 40 L of water, respectively, and then slowly add 100 mL of the disease-resistant water-soluble fertilizer prepared in Example 1-3 and Comparative Example 1-2 to 40 L of water, respectively, and control the addition time to be 1 min. During the addition process, stir the water at a stirring speed of 50 rpm. After the addition is completed, continue stirring for 2 min, and observe the dilution effect. The observation results are as follows:

[0140]

[0141] Test Example 5

[0142] In Shouguang City, Weifang City, Shandong Province, a 300m 2 The wheat planting land is divided into 6 plots, each with an area of ​​50m 2 , and numbered them, numbered them as planting plots 1-6, isolated them from each other, and then on October 10, 2023, wheat seeds of the variety Jimai 22 were sown on planting plots 1-6, with a sowing density of 200 seeds / cm 2 , except for the use of fertilizers, other planting management methods such as pesticide use and watering management in planting plots 1-6 are kept the same;

[0143] Regarding the use of fertilizers, before sowing the No. 1-6 planting plots, compound fertilizer 25-13-7 was used as base fertilizer, and the base fertilizer dosage of the No. 1-6 planting plots was 2.3 kg. Urea was used to strengthen nitrogen nutrition for the No. 1-6 planting plots during the jointing stage of wheat, and the urea dosage of the No. 1-6 planting plots was 1 kg. Then, the No. 1-5 planting plot was used as a test planting plot, and the 400-fold solution of the disease-resistant water-soluble fertilizer prepared in Example 1-3 and Comparative Example 1-2 was used to spray the No. 1-5 planting plots once during the jointing stage, booting stage, and filling stage of wheat, respectively. The No. 6 planting plot was used as a blank control, and no water-soluble fertilizer was used. The specific corresponding relationship is as follows:

[0144]

[0145] When the 400-fold solution of the disease-resistant water-soluble fertilizer prepared in Example 1-3 and Comparative Example 1-2 was used to spray the planting sites 1-5, the amount of the disease-resistant water-soluble fertilizer used in the planting sites 1-5 was 300 mL each time;

[0146] The maturity period and yield of planting plots 1-6 were counted respectively, and the statistical results are as follows:

[0147]

[0148] The incidence of powdery mildew and sheath blight in planting plots 1-6 during the planting period was statistically analyzed. Based on the statistical incidence of powdery mildew and sheath blight, the control effect of powdery mildew and sheath blight was calculated. The calculation formula and results are as follows:

[0149] Control effect = (incidence of blank control - incidence of test planting area) / incidence of blank control × 100%;

[0150]

[0151] It can be seen from the results of Test Examples 1-5 that by adding the first nanoparticles in the preparation of the disease-resistant water-soluble fertilizer, the appearance, storage resistance, dilution effect, and dilution speed of the prepared disease-resistant water-soluble fertilizer can be improved, and it can also ensure that frequent fertilization is not required, thereby improving the disease resistance of crops and increasing the growth rate and yield of crops;

[0152] By adding the second nanoparticles in the preparation of disease-resistant water-soluble fertilizers, it can be ensured that the prepared disease-resistant water-soluble fertilizers are not prone to flatulence problems when stored at high temperatures, and it can also ensure that frequent fertilization is not required, thereby improving the growth rate and yield of crops while improving the disease resistance of crops.

[0153] Unless otherwise specified, all percentages used in the present invention are by mass.

[0154] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a disease-resistant water-soluble fertilizer, characterized in that: The method comprises the following steps: preparing first nanoparticles, preparing second nanoparticles, dissolving, suspending and mixing; The preparation of the first nanoparticles comprises the following steps: preparing a chitosan aqueous solution, acid treatment, adsorption, cross-linking, fixing zinc ions, and chelation; The preparation of the chitosan aqueous solution comprises mixing chitosan and an acetic acid aqueous solution, and stirring at room temperature to obtain a chitosan aqueous solution; The acid treatment comprises mixing nano-diatomaceous earth and hydrochloric acid aqueous solution, stirring at room temperature, centrifuging, washing the precipitate, and drying to obtain acid-treated diatomaceous earth; The adsorption comprises mixing the acid-treated diatomaceous earth and the chitosan aqueous solution, stirring at room temperature, centrifuging, washing the precipitate, and drying to obtain the adsorbed diatomaceous earth; The cross-linking comprises mixing the adsorbed diatomaceous earth and water, stirring at 35-40° C., adding glutaraldehyde aqueous solution, continuing stirring after the addition is completed, centrifuging, washing the precipitate, and drying to obtain the cross-linked diatomaceous earth; The zinc ion fixing method comprises mixing the cross-linked diatomaceous earth and the zinc chloride aqueous solution, stirring at room temperature, adding the hydrochloric acid aqueous solution, continuing stirring, centrifuging, washing the precipitate, and drying to obtain the diatomaceous earth with fixed zinc ions; The chelation comprises mixing the diatomaceous earth with fixed zinc ions and the aqueous solution of polyvinyl alcohol 1788, stirring at room temperature, adding the aqueous solution of hydrochloric acid, continuing stirring, centrifuging, washing the precipitate, and drying to obtain the first nanoparticles; The preparation of the second nanoparticles comprises the following steps: activation, grafting, and coating; The activation comprises mixing the nano-activated carbon and concentrated hydrochloric acid, stirring at room temperature, centrifuging, washing the precipitate, and drying to obtain activated activated carbon; The grafting comprises mixing the activated activated carbon, epichlorohydrin and N,N-dimethylacetamide, stirring at 80-85° C., adding ethylenediamine, continuing to stir after the addition is completed, adding triethylamine, continuing to stir, centrifuging, washing the precipitate, and drying to obtain the grafted activated carbon; The coating comprises mixing the grafted activated carbon and polyvinyl pyrrolidone K30 aqueous solution, stirring at room temperature, centrifuging, washing the precipitate, and drying to obtain the second nanoparticles; The dissolution comprises mixing dipotassium hydrogen phosphate, potassium dihydrogen phosphate and water, stirring at 70-75° C., adding potassium sulfate and potassium nitrate, continuing stirring, cooling to room temperature, adding urea, continuing stirring after the addition is completed, adding EDTA-Ca, EDTA-Mg, EDTA-Zn and EDTA-Fe, continuing stirring to obtain a dissolved solution; The suspension comprises mixing the first nanoparticles, the second nanoparticles and water, stirring at 60-65° C., adding potassium humate, potassium L-glutamate and polyvinyl pyrrolidone, and continuing to stir to obtain a suspension; The suspension is stirred at room temperature, and the dissolved liquid is added into the suspension. After the addition is completed, stirring is continued to obtain a disease-resistant water-soluble fertilizer.

2. The method for preparing the disease-resistant water-soluble fertilizer according to claim 1, characterized in that: In the preparation of the chitosan aqueous solution, the mass volume ratio of chitosan to acetic acid aqueous solution is 18-20g:1000-1100mL; The mass fraction of the acetic acid aqueous solution is 2-2.5%; The weight average molecular weight of the chitosan is 150,000, and the degree of deacetylation is 90%.

3. The method for preparing the disease-resistant water-soluble fertilizer according to claim 1, characterized in that: In the acid treatment, the mass volume ratio of nano-diatomaceous earth and hydrochloric acid aqueous solution is 24-25g:250-300mL; The mass fraction of the hydrochloric acid aqueous solution is 5%; The average particle size of the nano diatomite is 100 nm; In the adsorption, the mass volume ratio of the acid-treated diatomaceous earth and the chitosan aqueous solution is 20-21 g: 1800-2000 mL; In the cross-linking, the mass volume ratio of the adsorbed diatomaceous earth, water, and glutaraldehyde aqueous solution is 45-48 g: 1000-1200 mL: 170-180 mL; The mass concentration of the glutaraldehyde aqueous solution is 20%; The addition rate of the glutaraldehyde aqueous solution is 10-12 mL / min.

4. The method for preparing the disease-resistant water-soluble fertilizer according to claim 1, characterized in that: In the fixed zinc ion, the mass volume ratio of the cross-linked diatomaceous earth, the zinc chloride aqueous solution, and the hydrochloric acid aqueous solution is 47-50 g: 1400-1500 mL: 2-3 mL; The mass fraction of the zinc chloride aqueous solution is 5%; The mass fraction of the hydrochloric acid aqueous solution is 5%.

5. The method for preparing the disease-resistant water-soluble fertilizer according to claim 1, characterized in that: In the chelation, the mass volume ratio of the diatomaceous earth after the zinc ions are fixed, the polyvinyl alcohol 1788 aqueous solution, and the hydrochloric acid aqueous solution is 45-46g:3100-3300mL:6-7mL; The mass fraction of the polyvinyl alcohol 1788 aqueous solution is 10%; The mass fraction of the hydrochloric acid aqueous solution is 5%.

6. The method for preparing the disease-resistant water-soluble fertilizer according to claim 1, characterized in that: In the activation, the mass volume ratio of nano-activated carbon and concentrated hydrochloric acid is 42-45g:270-300mL; The mass fraction of concentrated hydrochloric acid is 37%; The average particle size of the nano activated carbon is 100 nm; In the grafting, the mass volume ratio of activated carbon, epichlorohydrin, N,N-dimethylacetamide, ethylenediamine and triethylamine is 56-60g:140-150mL:140-160mL:60-70mL:140-150mL; The addition rate of the ethylenediamine is 3-4 mL / min; In the coating, the mass volume ratio of the grafted activated carbon and the polyvinyl pyrrolidone K30 aqueous solution is 58-60g:900-1000mL; The mass fraction of the polyvinyl pyrrolidone K30 aqueous solution is 5%.

7. The method for preparing the disease-resistant water-soluble fertilizer according to claim 1, characterized in that: In the dissolution, the mass volume ratio of dipotassium hydrogen phosphate, potassium dihydrogen phosphate, water, potassium sulfate, potassium nitrate, urea, EDTA-Ca, EDTA-Mg, EDTA-Zn, and EDTA-Fe is 16-18 g: 7-8 g: 60-70 mL: 30-32 g: 5-6 g: 45-50 g: 4-5 g: 2-3 g: 2-2.5 g: 1-1.3 g; The urea addition rate is 4-5 g / min.

8. The method for preparing the disease-resistant water-soluble fertilizer according to claim 1, characterized in that: In the suspension, the mass volume ratio of the first nanoparticles, the second nanoparticles, water, potassium humate, potassium L-glutamate, and polyvinyl pyrrolidone is 16-17 g: 5-5.5 g: 60-70 mL: 11-13 g: 2-2.5 g: 1.5-1.8 g.

9. The method for preparing the disease-resistant water-soluble fertilizer according to claim 1, characterized in that: In the mixing, the mass ratio of the first nanoparticles in the suspension to the dipotassium hydrogen phosphate in the dissolving solution is 16-17:16-18; The addition rate of the dissolving solution is 5-6 mL / min.

10. A disease-resistant water-soluble fertilizer prepared by the preparation method according to any one of claims 1 to 9.

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