Yield-increasing functional full-biodegradable controlled-release fertilizer and preparation method thereof

Abstract

The invention relates to the field of agricultural new materials, and provides a production-increasing functional full-biodegradable controlled-release fertilizer and a preparation method thereof.The production-increasing functional full-biodegradable controlled-release fertilizer is prepared by loading a functional substance onto a carrier to obtain a carrier-functional substance slow-release complex with a slow-release function, then blending and dissolving the carrier-functional substance slow-release complex with full-biodegradable resin and a solvent to obtain a coating solution, and then adding the coating solution into the full-biodegradable controlled-release fertilizer to obtain a finished product. Coating liquid is sprayed to the surfaces of fertilizer particles, the fertilizer particles are coated, and the yield-increasing functional full-biodegradable resin coated controlled-release fertilizer is prepared and can enable yield-increasing functional substances and fertilizer nutrients to be released synchronously, and the nutrient utilization rate is increased to the maximum extent. The final degradation products of the fully-biodegradable resin film material in soil are carbon dioxide and water, and the fully-biodegradable resin film material is green, environment-friendly and pollution-free, can replace traditional non-degradable polyethylene and polyurethane film materials, meets the requirements of green and sustainable development of agriculture in China, and has important economic, social and ecological benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of controlled-release fertilizers, and particularly relates to a yield-increasing fully biodegradable controlled-release fertilizer and a preparation method thereof. Summary of the invention

[0002] my country is a major fertilizer application country, and its fertilizer application volume ranks first in the world. Currently, polymer-coated controlled-release fertilizers have the function of improving nutrient utilization, and fertilizer utilization can be increased to 80%. However, currently commercial controlled-release fertilizers are mostly made of non-degradable plastics such as polyethylene, sulfur-added resins, and polyurethane. After application, the residual film is difficult to degrade in the soil, and long-term application will cause the problem of "white pollution" in farmland soil. Fully biodegradable resins are a type of green and environmentally friendly polymers that can be decomposed into carbon dioxide and water by microorganisms in the natural environment. They have been used in food packaging films, ground films, plastic bottles and other fields. The development of coated controlled-release fertilizers using fully biodegradable resins can solve the problem of residual film pollution of controlled-release fertilizers in farmland.

[0003] Although coated controlled-release fertilizers can improve nutrient utilization, the improvement is limited, and nearly 50% of fertilizer nutrients are still wasted. Yield-increasing functional substances have the function of promoting crop growth and increasing crop yields. Combining functional substances with coated controlled-release fertilizers to achieve nutrient controlled release and functionality of controlled-release fertilizer products is an effective way to further improve nutrient utilization.

[0004] In the prior art, the technical solution of Chinese Patent Application No. 201911380667.8 mixes powdered fertilizer and functional substances such as brassinolide, fulvic acid, humic acid, alginic acid, and diethylaminoethanol caproate that have not been subjected to any loading and sustained-release treatment, and adds the mixture to a granulator for granulation to obtain a functional slow-release fertilizer core, and then obtains a functional coated controlled-release fertilizer through a coating process; the technical solution of Chinese Patent Application No. 201911169969.0 mixes the functional substances such as brassinolide, fulvic acid, humic acid, alginic acid, and diethylaminoethanol caproate that have not been subjected to any loading and sustained-release treatment. Acid is directly added to the surface of diammonium phosphate, and then a functional polyurethane coated controlled-release fertilizer is obtained through a coating process; the technical solution of Chinese patent application No. 201810658019.3 directly mixes functional substances such as chitosan derivatives, brassinolide, fulvic acid, humic acid, seaweed extracts, diethylaminoethanol caproate, cyclodipeptide, seaweed polysaccharides, amino acid oligosaccharides, etc. that have not undergone any load-slow-release treatment into the controlled-release fertilizer film material, and develops functional coated controlled-release fertilizers coated with composite materials such as epoxy resin / polyurethane.

[0005] The existing coated controlled-release fertilizers have the following problems: (1) The membrane materials used in the above technology are non-degradable polyurethane, polyolefin wax, polyolefin, etc., which are difficult to degrade in the soil environment. Long-term use will cause white pollution of the soil; (2) The functional substances directly added to the membrane material without any treatment will be quickly released with water in the early stage of the crop growth period, but will lose the function of increasing production and promoting growth in the later stage of the crop growth period, while the fertilizer nutrients will be slowly released to meet the requirements of the entire crop growth period, which will lead to a release time difference. The functional substances and fertilizer nutrients cannot be released synchronously. The fertilizer is released throughout the entire crop growth period, but the yield-increasing functional substances only work in the early stage of the crop growth period.

[0006] In addition, there are also literature reports on the technical solutions of coated controlled-release fertilizers, but they generally require the use of multiple resins for compounding to meet the coating granulation process, and the corresponding film material has poor water and fertilizer barrier capabilities, making it difficult to achieve the expected controlled-release effect. Other materials can also be added to the film material, but the added materials are generally non-degradable materials such as paraffin, so they cannot meet the requirements of full biodegradability of the film material.

[0007] Therefore, the existing coated controlled-release fertilizers are difficult to meet the needs of agricultural development, and developing new coated controlled-release fertilizers has become a consensus among technicians in this field. Summary of the invention

[0009] In order to solve the problem that the film material of the coated controlled-release fertilizer in the prior art is difficult to degrade in the environment, and the functional substances in the controlled-release fertilizer are released too quickly, resulting in the inability to continuously play a role in promoting growth and increasing production during the entire growth period of the crop, the present invention provides a fully biodegradable controlled-release fertilizer with a yield-increasing function and a preparation method thereof, and uses a fully biodegradable resin as a film material to prepare a coated controlled-release fertilizer. The nutrients of the controlled-release fertilizer can be released completely within a functional period of 1-4 months. After the functional period, the film material can be degraded into carbon dioxide and water under the action of microorganisms in the soil, solving the problem that the film material of the coated controlled-release fertilizer is difficult to degrade in the soil and causes pollution. At the same time, the functional substance is loaded onto a carrier to obtain a carrier-functional substance slow-release complex with a slow-release function, and then the carrier is mixed and dissolved with a fully biodegradable resin and a solvent to obtain a coating liquid, and the coating liquid is sprayed onto the surface of the fertilizer particles, and the fertilizer particles are coated to obtain a fully biodegradable controlled-release fertilizer with a yield-increasing function.

[0010] The present invention first provides a method for preparing a yield-increasing functional fully biodegradable controlled-release fertilizer, and the specific steps are as follows:

[0011] (1) Preparation of carrier-functional substance sustained-release complex: The functional substance, carrier and deionized water are reacted under mechanical stirring and heating conditions. After the reaction is completed, the complex is cooled to room temperature, filtered, washed with deionized water and freeze-dried to obtain a carrier-functional substance sustained-release complex.

[0012] (2) blending and dissolving the carrier-functional substance sustained-release complex with a fully biodegradable resin and a solvent to obtain a coating solution;

[0013] (3) Spraying the coating liquid onto the surface of the fertilizer particles to coat the fertilizer particles, thereby obtaining a fully biodegradable controlled-release fertilizer with yield-increasing function.

[0014] Preferably, the carrier in step (1) is one or more of carbon dots, C60, giant carbon tubes, flour, and porous glass powder, and the particle size of the carrier is 1-100 nm;

[0015] Preferably, the functional substance in step (1) is one or more of production-increasing amines, production-increasing amine esters, aminoethyl esters, and synergistic amines.

[0016] Preferably, the carrier in step (1) is a giant carbon tube with a particle size of 10-20 nm.

[0017] Under the premise of the same specific surface area of ​​the carrier, the particle size of the carrier has a close relationship with the amount of functional substances that can be adsorbed per unit mass of the carrier. The larger the particle size, the less functional substances can be adsorbed per unit mass of the carrier; the smaller the particle size, the more functional substances can be adsorbed per unit mass of the carrier.

[0018] More preferably, the functional substance is diethylaminoethyl ester.

[0019] Aminoethyl hexanoate is a high-energy plant growth regulator with a broad spectrum and breakthrough effects, and its yield-increasing ability is the best among the functional substances mentioned above; there are a large number of micropores, mesopores and macropores inside the giant carbon tubes, and its specific surface area is the largest among the carriers mentioned above. By combining the two, the best effect of slow-release yield increase can be achieved.

[0020] Preferably, the ratio of the functional substance, the carrier, and the deionized water in step (1) is (1-10) g: (90-99) g: (100-500) mL;

[0021] More preferably, the ratio of the functional substance, the carrier and the deionized water in step (1) is 1 g:99 g:100 mL.

[0022] Preferably, in step (1), the stirring rate is 10 to 60 rpm, the heating temperature is 40 to 90° C., the reaction time is 1 to 10 h, the freeze-drying temperature is -80 to -5° C., and the freeze-drying time is 1 to 10 h.

[0023] Preferably, the fully biodegradable resin in step (2) is one or more of PHA, PVA, PHB, and PGA; the solvent is one or more of N,N-dimethylformamide, deionized water, carbon tetrachloride, ethyl acetate, toluene cyclohexanone, and hexafluoroisopropanol;

[0024] More preferably, in step (2), the fully biodegradable resin is PHB, and the solvent is carbon tetrachloride.

[0025] PHB has strong water and nutrient barrier capabilities and nutrient control release capabilities. Under the condition of achieving the same nutrient control release period, the amount of PHB used is lower; carbon tetrachloride has a low melting point, low production energy consumption, and is easier to recycle.

[0026] Preferably, the ratio of the carrier-functional substance sustained-release complex, the fully biodegradable resin and the solvent is (0.1-10) g: (90-99.9) g: 100 mL;

[0027] More preferably, the ratio of the carrier-functional substance sustained-release complex, the fully biodegradable resin and the solvent is 5g:95g:100mL.

[0028] Preferably, the blending and dissolution temperature is 10-120°C, the blending and dissolution time is 1-10h, the fertilizer particle size is 2-4mm, the fertilizer particle dosage is 5.5-10kg / time, the spray gun pressure is 0.5-200MPa, the induced air temperature is 90-160°C, the coating time is 40-380min, and the controlled-release fertilizer coating rate is 1.0-1.7wt% (calculated as carrier-functional substance sustained-release complex + degradation resin).

[0029] In addition, the inventor provides a fully biodegradable controlled-release fertilizer with yield-increasing function obtained by the above preparation method. The controlled-release fertilizer can release nutrients within 1-4 months, and after the release period, its film material can be degraded into carbon dioxide and water in the soil under the action of microorganisms within a few years, solving the problem of pollution caused by difficult degradation of coated controlled-release fertilizer film materials in the soil.

[0030] In addition, the present invention also claims protection for the yield-increasing functional fully biodegradable controlled-release fertilizer prepared based on the above preparation method.

[0031] In summary, the yield-increasing functional fully biodegradable resin-coated controlled-release fertilizer and its preparation method finally obtained in this application have the following advantages compared with the prior art: (1) The controlled-release fertilizer film material is fully biodegradable in farmland soil and will not cause the problem of white soil pollution; (2) The yield-increasing functional substance is loaded onto the carrier, achieving the effect of synchronous release of the yield-increasing functional substance and fertilizer nutrients, which continuously acts on the crop throughout its entire growth period. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a photo of the controlled-release fertilizer coating liquid described in Examples 1-3 of the present invention poured onto a glass plate, and a film was formed after the solvent evaporated. The film was buried in the soil for 180 days.

[0033] Figure 2The controlled-release fertilizer coating liquid described in Examples 1-3 of the present invention is poured onto a glass plate, and a film is formed after the solvent evaporates. The SEM images of the film surface before and 180 days after the film is buried in the soil are taken.

[0034] Figure 3 The controlled-release fertilizer coating solution described in Examples 1-3 of the present invention is poured onto a glass plate, and a film is formed after the solvent evaporates. AFM images of the film surface are taken before and 180 days after the film is buried in the soil.

[0035] Figure 4 The controlled-release fertilizer coating solution described in Examples 1-3 of the present invention is poured onto a glass plate, and a film is formed after the solvent evaporates. The FTIR spectra of the film surface before and 180 days after the film is buried in the soil are shown.

[0036] Figure 5 The controlled-release fertilizer coating liquid described in Examples 1-3 of the present invention is poured onto a glass plate, and a membrane is formed after the solvent evaporates. XPS spectra of the membrane surface before and 180 days after the membrane is buried in the soil are obtained. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described below in conjunction with specific embodiments. These embodiments are only used to illustrate the technical solution of the present invention in more detail and should not be construed as limiting the protection scope of the present invention.

[0038] The yield-increasing amine was purchased from Zhengzhou Chenjun Agrochemical Technology Co., Ltd., carbon dots were purchased from Hangzhou Xinqiao Biotechnology Co., Ltd., fast-acting urea was purchased from Hualu Hengsheng Chemical Co., Ltd., amine ester was purchased from Jiangsu Caiwei Biotechnology Co., Ltd., C60 was purchased from Wuhan Kanos Technology Co., Ltd., ammonium ester was purchased from Hebi Quanfeng Biotechnology Co., Ltd., giant carbon tubes were purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd., synergistic amine was purchased from Zhongshan Dixin Chemical Co., Ltd., porous glass powder was purchased from Donghai County Fucai Mineral Products Co., Ltd., and other substances or reagents used, unless otherwise specified, are all general commercially available products.

[0039] The coating rate detection method is to take 10.0g of coated urea and smash it with a hammer, then wash it with deionized water to remove all urea components, and finally put it in an oven at 60℃ to completely dry it. Use a 1 / 10,000 balance to weigh it, repeat three times and get the average value to calculate the final controlled-release urea coating rate.

[0040] Example 1

[0041] First, a carbon dot-yield-increasing amine sustained-release complex is prepared, and the specific steps are as follows:

[0042] Add the production-increasing amine, carbon dots and deionized water into a three-necked flask in a ratio of 2g:98g:300mL, wherein the particle size of the carbon dots is 1-10nm.

[0043] The mixture was heated to 40°C for reaction under mechanical stirring at 10 rpm for 1 hour. After the reaction, the mixture was cooled to room temperature, filtered, washed with deionized water, and freeze-dried at -5°C for 1 hour to obtain a carbon dot-yield-increasing amine sustained-release complex.

[0044] The above-mentioned carbon dot-yield-increasing amine slow-release complex is used as a raw material to prepare a yield-increasing functional fully biodegradable controlled-release urea, and the specific steps are as follows:

[0045] The carbon dot-yield-increasing amine sustained-release complex, PHA and N,N-dimethylformamide were blended and dissolved in a ratio of 0.1 g:99.9 g:100 mL to obtain a coating solution. The blending and dissolving temperature was 10° C. and the blending and dissolving time was 1 h.

[0046] Then the coating liquid is sprayed onto the surface of the urea particles. The particle size of the urea particles is 2 mm, the amount of urea particles is 10 kg / time, the urea particles are coated, the spray gun pressure is 0.5 MPa, the induced air temperature is 160°C, and the coating time is 40 minutes to obtain a yield-increasing functional biodegradable coated urea with a controlled-release urea coating rate of 1.0 wt%.

[0047] Comparative Example 1-1

[0048] A coated controlled-release urea, the preparation method of which is basically the same as the method for preparing the yield-increasing functional fully biodegradable controlled-release urea in Example 1, but in Comparative Example 1-1, the carbon dot-yield-increasing amine slow-release complex is not used as the raw material, but the yield-increasing amine is directly used as the raw material.

[0049] Specifically, the yield-increasing amine, PHA and N,N-dimethylformamide were mixed according to 0.002 g: 99.9 g: 100 mL, and the remaining steps were consistent with those in Example 1.

[0050] Comparative Example 1-2

[0051] A coated controlled-release urea, the preparation method of which is basically the same as the method for preparing the yield-increasing functional fully biodegradable controlled-release urea in Example 1, but in Comparative Example 1-2, the carbon dot-yield-increasing amine slow-release complex is not used as a raw material, and no functional substance is added to the raw materials.

[0052] Specifically, PHA and N,N-dimethylformamide were blended in a ratio of 99.9 g:100 mL, and the remaining steps were consistent with those in Example 1.

[0053] Comparative Examples 1-3

[0054] A commercial common coated controlled-release urea, specifically the polyurethane coated blue film controlled-release urea produced by Shandong Agricultural University Fertilizer Technology Co., Ltd.

[0055] Comparative Examples 1-4

[0056] A quick-acting urea was purchased from Hualu Hengsheng Chemical Co., Ltd., with a particle size of 2-4 mm and a nitrogen content of 46%.

[0057] Experimental Example 1-1

[0058] The release characteristics of controlled-release urea are tested according to the international standard ISO 18644 for controlled-release fertilizers. The 7-day release rate of urea refers to the cumulative release rate of urea nutrients in the fertilizer within 7 days, the 28-day release rate refers to the cumulative release rate of urea nutrients in the fertilizer within 28 days, and the release period refers to the number of days corresponding to the cumulative release rate of urea nutrients in the fertilizer reaching 80%.

[0059] The release characteristics of functional substances in controlled-release urea are tested according to the following methods:

[0060] 10 g of controlled-release fertilizer sample was put into a microporous mesh bag and then placed in a plastic bottle containing 200 mL of deionized water. Three replicates were set for each treatment and then cultured in a 25°C incubator. Samples were taken on the 1st, 3rd, 5th, 7th, 14th, 21st, and 28th day (n≥1), and the release characteristics of functional substances in the controlled-release urea membrane were measured using UV-visible spectrophotometry.

[0061] The 7-day release rate of functional substances refers to the cumulative nutrient release rate of functional substances in 7 days, the 28-day release rate refers to the cumulative nutrient release rate of functional substances in 28 days, and the release period refers to the number of days corresponding to the cumulative release rate of functional substances reaching 80%.

[0062] Among them, since Comparative Examples 1-4 are fast-acting urea and do not have sustained-release properties, their release characteristics are not tested.

[0063] As shown in Table 1, Example 1 prepared a yield-increasing functional fully biodegradable controlled-release urea product, the 7-day release rate of urea was: 9.13%; the 28-day release rate was: 55.67%; the nutrient controlled-release period was: 81.32 days; the 7-day release rate of the yield-increasing amine was: 8.64%; the 28-day release rate was: 41.91%; the nutrient controlled-release period was: 86.98 days.

[0064] For the coated controlled-release urea of ​​comparative example 1-1, the 7-day release rate of urea is 10.47%, the 28-day release rate is 50.43%, and the nutrient controlled-release period is 72.43 days; the 7-day release rate of the production-increasing amine is 11.73%, the 28-day release rate is 61.27%, and the nutrient controlled-release period is 47.82 days.

[0065] Therefore, the yield-increasing functional fully biodegradable controlled-release urea product prepared in Example 1 has better synchronization in the release rates of urea and yield-increasing amine and the nutrient controlled-release period compared with the coated controlled-release urea of ​​Comparative Example 1-1.

[0066] The controlled-release fertilizer coating solution prepared in Example 1 was poured onto a glass plate, and a film was formed after the solvent evaporated. After the film was buried in the soil for 180 days, a macroscopic photograph of the film surface ( Figure 1 ), SEM images of the membrane before and after burial ( Figure 2 ), AFM images of the membrane before and after burial ( Figure 3 ) can show that after 180 days of burial, the membrane was used by microorganisms in the soil, and the surface had become uneven, and the membrane was no longer intact, and part of it had been eroded and used by microorganisms. FTIR spectra of the membrane before and after burial ( Figure 4 ) Comparison shows that the CO single bond in the membrane becomes smaller, and the XPS spectra of the membrane before and after burial ( Figure 5 ) comparison found that the intensity of C1s in the diaphragm became smaller. These all indicate that microorganisms are eroding and utilizing the diaphragm by destroying its molecular structure, and will eventually slowly and completely degrade it into carbon dioxide and water, which is non-toxic and harmless.

[0067] Experimental Example 1-2

[0068] Using transplanted rice as the test crop, a field test of using carbon dots-yield-increasing amine slow-release complex as raw material to prepare degradable coated controlled-release urea was conducted in Hedong District, Linyi City, Shandong Province from June 2023 to October 2023. The average yield of the test field in the first five years was 6.10×10 3 kg / ha; the area of ​​a single test plot is 30m 2 The following examples and comparative examples were all tested in three test plots, and the final data were obtained by taking the average value.

[0069] The calculation of the yield increase rate is based on Comparative Examples 1-4, and the specific calculation formula is as follows.

[0070] Yield increase rate (%) = (yield of other examples - yield of comparative example 1-4) * 100% / yield of comparative example 1-4 increase in revenue = net income of other examples - net income of comparative example 1-4

[0071] The specific process is: the test fertilizer is spread into the test field as a base fertilizer at one time, and then the test fertilizer is plowed into the soil at a depth of 8-10cm, and then transplanting rice, the spacing between transplanted rice plants is 12cm, the row spacing is 24cm, the nitrogen application rate is 300kg / ha (pure), and the test nitrogen material is: the yield-increasing functional fully biodegradable controlled-release urea prepared in Example 1 accounts for 30% (90kg / ha) of the total mass of urea, and the quick-acting urea accounts for 70% (210kg / ha) of the total mass of urea. The quick-acting urea in the test fertilizer (purchased from Hualu Hengsheng Chemical Co., Ltd., with a particle size of 2-4mm and a nitrogen content of 46%) can provide the nitrogen required for the early growth of transplanted rice; the controlled-release urea in the test fertilizer can provide the nitrogen required for the late growth of transplanted rice. The phosphate fertilizer used was superphosphate (purchased from Yunnan Xingkun Chemical Co., Ltd., with a total phosphorus content of ≥46.0%), and the phosphorus application rate was 150 kg / ha (pure); the potash fertilizer used was potassium sulfate (purchased from Shandong Haihua Co., Ltd., with a potassium content of ≥50.0%), and the potassium application rate was 200 kg / ha (pure). All nitrogen, phosphorus and potassium fertilizers were applied all at once as base fertilizers when transplanting rice, and no additional topdressing was required. The management measures for transplanted rice fields were the same as the conventional management measures of farmers.

[0072] As shown in Table 2, the yield-increasing fully biodegradable controlled-release urea prepared in Example 1 under the above treatment had a rice seed yield of 7.23×10 3 kg / ha, total income is: 25305.00 yuan / ha, net income is: 7991.28 yuan / ha, and the increase is 4058.39 yuan / ha.

[0073] Comparative Example 1-1: By weight percentage, the PHA coated controlled-release urea prepared in Comparative Example 1-1 (with the addition of the yield-increasing amine that has not been subjected to loading treatment) accounts for 30% (90 kg / ha) of the total mass of urea, and the quick-acting urea accounts for 70% (210 kg / ha) of the total mass of urea; other factors are consistent with the relevant treatments in the above Example 1. The seed yield of transplanted rice is: 6.79×10 3 kg / ha, total income is: 23765.00 yuan / ha, net income is: 6517.60 yuan / ha, increased income is 2584.71 yuan / ha.

[0074] Comparative Example 1-2: By weight percentage, the PHA coated controlled-release urea prepared in Comparative Example 1-2 (without any functional substance) accounts for 30% (90 kg / ha) of the total urea mass, and the quick-acting urea accounts for 70% (210 kg / ha) of the total urea mass; other factors are consistent with the relevant treatment of Example 1 above. The seed yield of transplanted rice is: 6.53×10 3 kg / ha, total income is: 22855.00 yuan / ha, net income is: 5673.92 yuan / ha, increased income is 1741.03 yuan / ha.

[0075] Comparative Examples 1-3: By weight percentage, the commercial coated controlled-release urea (polyurethane coated blue film controlled-release urea produced by Shandong Agricultural University Fertilizer Technology Co., Ltd.) described in Comparative Examples 1-3 accounted for 30% (90 kg / ha) of the total urea mass, and the quick-acting urea accounted for 70% (210 kg / ha) of the total urea mass; other factors were consistent with the relevant treatments in the above Example 1. The seed yield of transplanted rice was: 6.46×10 3 kg / ha, total income is: 22610.00 yuan / ha, net income is: 5163.64 yuan / ha, increased income is 1230.75 yuan / ha.

[0076] Comparative Examples 1-4: The proportion of quick-acting urea by weight percentage was 100% (quick-acting urea was applied twice, namely, basal application and topdressing, of which basal application accounted for 70% (210 kg / ha) of the total urea weight when transplanting rice seedlings, and topdressing accounted for 30% (90 kg / ha) of the total urea weight one month after transplanting; phosphorus fertilizer and potassium fertilizer were applied once as basal fertilizer); other factors were consistent with the relevant treatments in the above Example 1. The seed yield of transplanted rice was: 6.19×10 3 kg / ha, total income is: 21665.00 yuan / ha, net income is: 3932.89 yuan / ha.

[0077] Compared with comparative examples 1-1, 1-2, 1-3, and 1-4, the transplanted rice treated by the scheme of application example 1 has the largest yield (7.23×103 kg / ha) and the largest net income (7991.28 yuan / ha), with an increase of 4058.39 yuan / ha.

[0078] Example 2

[0079] First, a C60-aminoester sustained-release complex is prepared, and the specific steps are as follows:

[0080] Add amine ester, C60 and deionized water into a three-necked flask in a ratio of 5g:95g:200mL, wherein the particle size of C60 is 20-50nm.

[0081] The mixture was heated to 60°C for reaction under mechanical stirring at 30 rpm for 4 hours. After the reaction, the mixture was cooled to room temperature, filtered, washed with deionized water, and freeze-dried at -20°C for 5 hours to obtain a C60-aminoester sustained-release complex.

[0082] The above-mentioned C60-aminoester sustained-release complex is used as a raw material to prepare the yield-increasing functional fully biodegradable controlled-release urea, and the specific steps are as follows:

[0083] The C60-aminoester sustained-release complex, PVA and deionized water were blended and dissolved in a ratio of 3 g:97 g:100 mL to obtain a coating solution. The blending and dissolving temperature was 50° C. and the blending and dissolving time was 3 h.

[0084] Then the coating liquid is sprayed onto the surface of the urea particles. The particle size of the urea particles is 2 mm, the amount of urea particles is 7.5 kg / time, the urea particles are coated, the spray gun pressure is 50 MPa, the induced air temperature is 110°C, and the coating time is 120 min. A yield-increasing functional biodegradable coated urea is obtained, and the controlled-release urea coating rate is 1.3 wt%.

[0085] Comparative Example 2-1

[0086] A coated controlled-release urea, the preparation method of which is basically the same as the method for preparing the yield-increasing functional fully biodegradable controlled-release urea in Example 2, but in Comparative Example 2-1, C60-aminoester sustained-release complex is not used as a raw material, but aminoester is directly used as a raw material.

[0087] Specifically, the amine ester, PVA and deionized water are mixed according to 0.15g:97g:100mL, and the remaining steps are consistent with those in Example 2.

[0088] Comparative Example 2-2

[0089] A coated controlled-release urea, the preparation method of which is basically the same as the method for preparing the yield-increasing functional fully biodegradable controlled-release urea in Example 2, but in Comparative Example 2-2, C60-aminoester sustained-release complex is not used as a raw material, and no functional substance is added to the raw materials.

[0090] Specifically, PVA and deionized water were blended in a ratio of 97 g:100 mL, and the remaining steps were consistent with those in Example 2.

[0091] Experimental Example 2-1

[0092] As shown in Table 1, Example 2 prepared a yield-increasing functional fully biodegradable controlled-release urea product, the 7-day release rate of urea was 28.02%, the 28-day release rate was 64.03%, and the nutrient controlled-release period was 58.41 days; the 7-day release rate of the amine ester was 22.40%, the 28-day release rate was 55.90%; the nutrient controlled-release period was 63.98 days.

[0093] For the coated controlled-release urea of ​​comparative example 2-1, the 7-day release rate of urea is 23.97%, the 28-day release rate is 63.07%, and the nutrient controlled-release period is 54.67 days; the 7-day release rate of amine ester is 32.97%, the 28-day release rate is 70.93%, and the nutrient controlled-release period is 35.58 days.

[0094] Therefore, the yield-increasing functional fully biodegradable controlled-release urea product prepared in Example 2 has better synchronization in the release rate of urea and amine ester and the nutrient controlled-release period compared with the coated controlled-release urea of ​​Comparative Example 2-1.

[0095] The controlled-release fertilizer coating solution prepared in Example 2 was poured onto a glass plate, and a film was formed after the solvent evaporated. After the film was buried in the soil for 180 days, a macroscopic photograph of the film surface ( Figure 1 ), SEM images of the membrane before and after burial ( Figure 2 ), AFM images of the membrane before and after burial ( Figure 3 ) can show that after 180 days of burial, the membrane was used by microorganisms in the soil, and the surface had become uneven, and the membrane was no longer intact, and part of it had been eroded and used by microorganisms. FTIR spectra of the membrane before and after burial ( Figure 4 ) Comparison shows that the CO single bond in the membrane becomes smaller, and the XPS spectra of the membrane before and after burial ( Figure 5 ) comparison found that the intensity of C1s in the diaphragm became smaller. These all indicate that microorganisms are eroding and utilizing the diaphragm by destroying its molecular structure, and will eventually slowly and completely degrade it into carbon dioxide and water, which is non-toxic and harmless.

[0096] Experimental Example 2-2

[0097] Using transplanted rice as the test crop, a field test of using C60-aminoester slow-release complex as raw material to prepare degradable coated controlled-release urea was conducted in Hedong District, Linyi City, Shandong Province from June 2023 to October 2023. The average yield of the test field in the first five years was 6.10×10 3 kg / ha; the area of ​​a single test plot is 30m 2 The following examples and comparative examples were all tested in three test plots, and the final data were obtained by taking the average value.

[0098] Yield increase rate (%) = (yield of other examples - yield of comparative example 1-4) * 100% / yield of comparative example 1-4 increase in revenue = net income of other examples - net income of comparative example 1-4

[0099] The specific process is: the test fertilizer is spread into the test field as a base fertilizer at one time, and then the test fertilizer is plowed into the soil at a depth of 8-10cm, and then transplanting rice, the spacing between transplanted rice plants is 12cm, the row spacing is 24cm, the nitrogen application rate is 300kg / ha (pure), and the test nitrogen material is: the yield-increasing functional fully biodegradable controlled-release urea prepared in Example 2 accounts for 30% (90kg / ha) of the total mass of urea, and the quick-acting urea accounts for 70% (210kg / ha) of the total mass of urea. The quick-acting urea in the test fertilizer (purchased from Hualu Hengsheng Chemical Co., Ltd., with a particle size of 2-4mm and a nitrogen content of 46%) can provide the nitrogen required for the early growth of transplanted rice; the controlled-release urea in the test fertilizer can provide the nitrogen required for the late growth of transplanted rice. The phosphate fertilizer used was superphosphate (purchased from Yunnan Xingkun Chemical Co., Ltd., with a total phosphorus content of ≥46.0%), and the phosphorus application rate was 150 kg / ha (pure); the potash fertilizer used was potassium sulfate (purchased from Shandong Haihua Co., Ltd., with a potassium content of ≥50.0%), and the potassium application rate was 200 kg / ha (pure). All nitrogen, phosphorus and potassium fertilizers were applied all at once as base fertilizers when transplanting rice, and no additional topdressing was required. The management measures for transplanted rice fields were the same as the conventional management measures of farmers.

[0100] As shown in Table 2, the yield-increasing fully biodegradable controlled-release urea prepared in Example 2 under the above treatment had a rice seed yield of 7.51×10 3 kg / ha, total income is: 26285.00 yuan / ha, net income is: 8938.12 yuan / ha, increased income is 5005.23 yuan / ha.

[0101] Comparative Example 2-1: By weight percentage, the PVA coated controlled-release urea prepared in Comparative Example 2-1 (with the addition of unloaded amine ester) accounts for 30% (90 kg / ha) of the total mass of urea, and the quick-acting urea accounts for 70% (210 kg / ha) of the total mass of urea; other factors are consistent with the relevant treatment of Example 2 above. The seed yield of transplanted rice is: 6.91×10 3 kg / ha, total income is: 24185.00 yuan / ha, net income is: 6904.44 yuan / ha, increased income is 2971.55 yuan / ha.

[0102] Comparative Example 2-2: In terms of weight percentage, the PVA coated controlled-release urea prepared in Comparative Example 2-2 (without any functional substance) accounts for 30% (90 kg / ha) of the total urea mass, and the quick-acting urea accounts for 70% (210 kg / ha) of the total urea mass; other factors are consistent with the relevant treatments in the above Example 2. The seed yield of transplanted rice is: 6.82×10 3 kg / ha, total income is: 23870.00 yuan / ha, net income is: 6655.76 yuan / ha, increased income is 2722.87 yuan / ha.

[0103] Compared with comparative examples 2-1, 2-2, 1-3, and 1-4, the transplanted rice yield treated by the solution of application example 2 was the largest (7.51×10 3 kg / ha), with the largest net income (8938.12 yuan / ha), and an increase of 5005.23 yuan / ha.

[0104] Example 3

[0105] First, a giant carbon tube-aminoethyl hexanoate sustained-release complex is prepared, and the specific steps are as follows:

[0106] Add ammonium ethyl ester, giant carbon tubes and deionized water into a three-necked flask in a ratio of 1g:99g:100mL, wherein the particle size of the giant carbon tubes is 10-20nm.

[0107] The mixture was heated to 75°C for reaction under mechanical stirring at 50 rpm for 8 hours. After the reaction, it was cooled to room temperature, filtered, washed with deionized water, and freeze-dried at -50°C for 7 hours to obtain a giant carbon tube-aminoethyl ester sustained-release complex.

[0108] The above-mentioned giant carbon tube-aminoethyl hexanoate slow-release complex is used as a raw material to prepare a yield-increasing functional fully biodegradable controlled-release urea, and the specific steps are as follows:

[0109] The giant carbon tube-aminoethyl hexanoate sustained-release complex, PHB and carbon tetrachloride were blended and dissolved in a ratio of 5g:95g:100mL to obtain a coating solution. The blending and dissolving temperature was 70°C and the blending and dissolving time was 6h.

[0110] Then the coating liquid is sprayed onto the surface of the urea particles. The particle size of the urea particles is 3 mm, the amount of urea particles is 6.5 kg / time, the urea particles are coated, the spray gun pressure is 100 MPa, the induced air temperature is 90°C, and the coating time is 220 min. A yield-increasing functional biodegradable coated urea is obtained, and the controlled-release urea coating rate is 1.5 wt%.

[0111] Comparative Example 3-1

[0112] A coated controlled-release urea, the preparation method of which is basically the same as the method for preparing the yield-increasing functional fully biodegradable controlled-release urea in Example 3, but in Comparative Example 3-1, the giant carbon tube-aminoethyl hexanoate sustained-release complex is not used as the raw material, but aminoethyl hexanoate is directly used as the raw material.

[0113] Specifically, ammonium hexanoate, PHB and carbon tetrachloride were mixed according to 0.05 g:95 g:100 mL, and the remaining steps were consistent with those in Example 3.

[0114] Comparative Example 3-2

[0115] A coated controlled-release urea, the preparation method of which is basically the same as the method for preparing the yield-increasing functional fully biodegradable controlled-release urea in Example 3, but in Comparative Example 3-2, the giant carbon tube-aminoethyl hexanoate sustained-release complex is not used as a raw material, and no functional substance is added to the raw materials.

[0116] Specifically, PHB and carbon tetrachloride were blended in a ratio of 95 g:100 mL, and the remaining steps were the same as those in Example 3.

[0117] Experimental Example 3-1

[0118] As shown in Table 1, Example 3 prepared a yield-increasing functional fully biodegradable controlled-release urea product, the 7-day release rate of urea was 1.17%, the 28-day release rate was 29.80%, and the nutrient controlled-release period was 95.58 days; the 7-day release rate of aminoethyl hexanoate was 2.10%, the 28-day release rate was 26.43%; the nutrient controlled-release period was 106.67 days.

[0119] For the coated controlled-release urea of ​​comparative example 3-1, the 7-day release rate of urea is 1.10%, the 28-day release rate is 20.53%, and the nutrient controlled-release period is 89.50 days; the 7-day release rate of aminoethyl hexanoate is 4.40%, the 28-day release rate is 37.53%, and the nutrient controlled-release period is 49.55 days.

[0120] Therefore, the yield-increasing functional fully biodegradable controlled-release urea product prepared in Example 3 has better synchronization in the release rates of urea and diethylaminoethyl ester and the nutrient controlled-release period compared with the coated controlled-release urea of ​​Comparative Example 3-1.

[0121] The controlled-release fertilizer coating solution prepared in Example 3 was poured onto a glass plate, and a film was formed after the solvent evaporated. After the film was buried in the soil for 180 days, a macroscopic photograph of the film surface ( Figure 1 ), SEM images of the membrane before and after burial ( Figure 2 ), AFM images of the membrane before and after burial ( Figure 3 ) can show that after 180 days of burial, the membrane was used by microorganisms in the soil, and the surface had become uneven, and the membrane was no longer intact, and part of it had been eroded and used by microorganisms. FTIR spectra of the membrane before and after burial ( Figure 4 ) Comparison shows that the CO single bond in the membrane becomes smaller, and the XPS spectra of the membrane before and after burial ( Figure 5 ) comparison found that the intensity of C1s in the diaphragm became smaller. These all indicate that microorganisms are eroding and utilizing the diaphragm by destroying its molecular structure, and will eventually slowly and completely degrade it into carbon dioxide and water, which is non-toxic and harmless.

[0122] Experimental Example 3-2

[0123] Using transplanted rice as the test crop, a field experiment was conducted in Hedong District, Linyi City, Shandong Province from June 2023 to October 2023 to prepare degradable coated controlled-release urea using giant carbon tube-aminoethyl ester slow-release complex as raw material. The average yield of the test field in the first five years was 6.10×10 3 kg / ha; the area of ​​a single test plot is 30m 2 The following examples and comparative examples were all tested in three test plots, and the final data were obtained by taking the average value.

[0124] Yield increase rate (%) = (yield of other examples - yield of comparative example 1-4) * 100% / yield of comparative example 1-4 increase in revenue = net income of other examples - net income of comparative example 1-4

[0125] The specific process is: the test fertilizer is spread into the test field as a base fertilizer at one time, and then the test fertilizer is plowed into the soil at a depth of 8-10cm, and then transplanted, the spacing between transplanted rice plants is 12cm, the row spacing is 24cm, the nitrogen application rate is 300kg / ha (pure), and the test nitrogen material is: the yield-increasing functional fully biodegradable controlled-release urea prepared in Example 3 accounts for 30% (90kg / ha) of the total mass of urea, and the quick-acting urea accounts for 70% (210kg / ha) of the total mass of urea. The quick-acting urea in the test fertilizer (purchased from Hualu Hengsheng Chemical Co., Ltd., with a particle size of 2-4mm and a nitrogen content of 46%) can provide the nitrogen required for the early growth of transplanted rice; the controlled-release urea in the test fertilizer can provide the nitrogen required for the late growth of transplanted rice. The phosphate fertilizer used was superphosphate (purchased from Yunnan Xingkun Chemical Co., Ltd., with a total phosphorus content of ≥46.0%), and the phosphorus application rate was 150 kg / ha (pure); the potash fertilizer used was potassium sulfate (purchased from Shandong Haihua Co., Ltd., with a potassium content of ≥50.0%), and the potassium application rate was 200 kg / ha (pure). All nitrogen, phosphorus and potassium fertilizers were applied all at once as base fertilizers when transplanting rice, and no additional topdressing was required. The management measures for transplanted rice fields were the same as the conventional management measures of farmers.

[0126] As shown in Table 2, the yield-increasing fully biodegradable controlled-release urea prepared in Example 3 under the above treatment had a rice seed yield of 8.54×10 3 kg / ha, total income is: 29890.00 yuan / ha, net income is: 12563.02 yuan / ha, increased income is 8630.13 yuan / ha.

[0127] Comparative Example 3-1: By weight percentage, the PHB coated controlled-release urea prepared in Comparative Example 3-1 (with the addition of aminoethyl hexanoate that has not been subjected to loading treatment) accounts for 30% (90 kg / ha) of the total mass of urea, and the quick-acting urea accounts for 70% (210 kg / ha) of the total mass of urea; other factors remain consistent with the relevant treatments in the above Example 3. The seed yield of transplanted rice is: 7.03×10 3kg / ha, total income is: 24605.00 yuan / ha, net income is: 7344.34 yuan / ha, increased income is 3411.45 yuan / ha.

[0128] Comparative Example 3-2: By weight percentage, the PHB coated controlled-release urea prepared in Comparative Example 3-2 (without any functional substance) accounts for 30% (90 kg / ha) of the total urea mass, and the quick-acting urea accounts for 70% (210 kg / ha) of the total urea mass; other factors are consistent with the relevant treatments in the above Example 3. The seed yield of transplanted rice is: 6.94×10 3 kg / ha, total income is: 24290.00 yuan / ha, net income is: 7095.66 yuan / ha, and the increase is 3162.77 yuan / ha.

[0129] Compared with comparative examples 3-1, 3-2, 1-3, and 1-4, the transplanted rice yield treated by the solution of application example 3 was the largest (8.54×10 3 kg / ha), with the largest net income (12563.02 yuan / ha), and an increase of 8630.13 yuan / ha.

[0130] Example 4

[0131] First, a porous glass powder-synergistic amine sustained-release complex is prepared, and the specific steps are as follows:

[0132] Add synergistic amine, porous glass powder and deionized water into a three-necked flask in a ratio of 10g:90g:500mL, wherein the particle size of the porous glass powder is 50-100nm.

[0133] The mixture was heated to 90°C for reaction under mechanical stirring at 60 rpm for 10 hours. After the reaction, the mixture was cooled to room temperature, filtered, washed with deionized water, and freeze-dried at -80°C for 10 hours to obtain a porous glass powder-synergist amine sustained-release complex.

[0134] The above-mentioned porous glass powder-synergistic amine slow-release complex is used as a raw material to prepare the yield-increasing functional fully biodegradable controlled-release urea, and the specific steps are as follows:

[0135] The porous glass powder-synergistic amine sustained-release complex, PGA and ethyl acetate were blended and dissolved in a ratio of 10 g:90 g:100 mL to obtain a coating solution. The blending and dissolving temperature was 70° C. and the blending and dissolving time was 10 h.

[0136] Then the coating liquid is sprayed onto the surface of the urea particles. The particle size of the urea particles is 4 mm, the amount of urea particles is 5.5 kg / time, the urea particles are coated, the spray gun pressure is 200 MPa, the induced air temperature is 140°C, and the coating time is 380 min. A yield-increasing functional biodegradable coated urea is obtained, and the controlled-release urea coating rate is 1.7 wt%.

[0137] Comparative Example 4-1

[0138] A coated controlled-release urea, the preparation method of which is basically the same as the method for preparing the yield-increasing functional fully biodegradable controlled-release urea in Example 4, but in Comparative Example 4-1, the porous glass powder-synergist amine slow-release complex is not used as the raw material, but the synergist amine is directly used as the raw material.

[0139] Specifically, the synergistic amine, PGA and ethyl acetate were blended according to 1 g:90 g:100 mL, and the remaining steps were consistent with Example 4.

[0140] Comparative Example 4-2

[0141] A coated controlled-release urea, the preparation method of which is basically the same as the method for preparing the yield-increasing functional fully biodegradable controlled-release urea in Example 4, but in Comparative Example 4-2, the porous glass powder-synergistic amine slow-release complex is not used as a raw material, and no functional substance is added to the raw materials.

[0142] Specifically, PGA and ethyl acetate are blended in a ratio of 90 g:100 mL, and the remaining steps are consistent with those in Example 4.

[0143] Experimental Example 4-1

[0144] As shown in Table 1, Example 4 prepared a yield-increasing functional fully biodegradable controlled-release urea product, the 7-day release rate of urea was 4.73%, the 28-day release rate was 30.40%, and the nutrient controlled-release period was 102.72 days; the 7-day release rate of the synergistic amine was 2.73%, the 28-day release rate was 24.13%; the nutrient controlled-release period was 111.25 days.

[0145] For the coated controlled-release urea of ​​comparative example 4-1, the 7-day release rate of urea is 2.27%, the 28-day release rate is 15.10%, and the nutrient controlled-release period is 99.20 days; the 7-day release rate of synergistic amine is 2.75%, the 28-day release rate is 33.47%; and the nutrient controlled-release period is 53.24 days.

[0146] Therefore, the yield-increasing functional fully biodegradable controlled-release urea product prepared in Example 4 has better synchronization in the release rate of urea and synergistic amine and the nutrient controlled-release period compared with the coated controlled-release urea of ​​Comparative Example 4-1.

[0147] Experimental Example 4-2

[0148] Using transplanted rice as the test crop, a field test of using porous glass powder-synergistic amine slow-release complex as raw material to prepare degradable coated controlled-release urea was conducted in Hedong District, Linyi City, Shandong Province from June 2023 to October 2023. The average yield of the test field in the first five years was 6.10×10 3 kg / ha; the area of ​​a single test plot is 30m 2 The following examples and comparative examples were all tested in three test plots, and the final data were obtained by taking the average value.

[0149] Yield increase rate (%) = (yield of other examples - yield of comparative example 1-4) * 100% / yield of comparative example 1-4 increase in revenue = net income of other examples - net income of comparative example 1-4

[0150] The specific process is: the test fertilizer is spread into the test field as a base fertilizer at one time, and then the test fertilizer is plowed into the soil at a depth of 8-10cm, and then transplanting rice, the spacing between transplanted rice plants is 12cm, the row spacing is 24cm, the nitrogen application rate is 300kg / ha (pure), and the test nitrogen material is: the yield-increasing functional fully biodegradable controlled-release urea prepared in Example 4 accounts for 30% (90kg / ha) of the total mass of urea, and the quick-acting urea accounts for 70% (210kg / ha) of the total mass of urea. The quick-acting urea in the test fertilizer (purchased from Hualu Hengsheng Chemical Co., Ltd., with a particle size of 2-4mm and a nitrogen content of 46%) can provide the nitrogen required for the early growth of transplanted rice; the controlled-release urea in the test fertilizer can provide the nitrogen required for the late growth of transplanted rice. The phosphate fertilizer used was superphosphate (purchased from Yunnan Xingkun Chemical Co., Ltd., with a total phosphorus content of ≥46.0%), and the phosphorus application rate was 150 kg / ha (pure); the potash fertilizer used was potassium sulfate (purchased from Shandong Haihua Co., Ltd., with a potassium content of ≥50.0%), and the potassium application rate was 200 kg / ha (pure). All nitrogen, phosphorus and potassium fertilizers were applied all at once as base fertilizers when transplanting rice, and no additional topdressing was required. The management measures for transplanted rice fields were the same as the conventional management measures of farmers.

[0151] As shown in Table 2, the yield-increasing fully biodegradable controlled-release urea prepared in Example 4 under the above treatment had a rice seed yield of 8.02×10 3 kg / ha, total income is: 28070.00 yuan / ha, net income is: 10776.18 yuan / ha, and the increase is 6843.29 yuan / ha.

[0152] Comparative Example 4-1: By weight percentage, the PGA coated controlled-release urea prepared in Comparative Example 4-1 (with the addition of the synergistic amine that has not been subjected to loading treatment) accounts for 30% (90 kg / ha) of the total mass of urea, and the quick-acting urea accounts for 70% (210 kg / ha) of the total mass of urea; other factors are consistent with the relevant treatment of the above Example 4. The seed yield of transplanted rice is: 7.05×10 3 kg / ha, total income is: 24675.00 yuan / ha, net income is: 7447.50 yuan / ha, increased income is 3514.61 yuan / ha.

[0153] Comparative Example 4-2: By weight percentage, the PGA coated controlled-release urea prepared in Comparative Example 4-2 (without any functional substance) accounts for 30% (90 kg / ha) of the total urea mass, and the quick-acting urea accounts for 70% (210 kg / ha) of the total urea mass; other factors are consistent with the relevant treatment of Example 4 above. The seed yield of transplanted rice is: 6.87×10 3 kg / ha, total income is: 24045.00 yuan / ha, net income is: 6883.82 yuan / ha, increased income is 2950.93 yuan / ha.

[0154] Compared with comparative examples 4-1, 4-2, 1-3, and 1-4, the transplanted rice yield treated by the solution of application example 4 was the largest (8.02×10 3 kg / ha), with the largest net income (10776.18 yuan / ha), and an increase of 6843.29 yuan / ha.

[0155] Table 1 7-day release rate, 28-day release rate and nutrient controlled release period of the coated controlled release fertilizer of the present invention

[0156]

[0157]

[0158] Table 2 Rice yield, income, etc. after application of fertilizers in the embodiments and comparative examples on transplanted rice in Linyi

[0159]

[0160] Note: The purchase price of rice is 3.5 yuan / kg. Other expenses include: seed cost (50 yuan / mu), transplanting cost (300 yuan / mu), pesticide cost (200 yuan / mu), water cost (60 yuan / mu), mechanical tillage cost (60 yuan / mu), harvesting and transportation cost (50 yuan / mu); labor expenses: base fertilizer and topdressing are both 25 yuan / mu / time, spraying (60 yuan / mu), and field management (80 yuan / mu).

[0161] It can be seen that among the above embodiments, embodiment 3 has the best effect and can be widely promoted and applied.

[0162] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any equivalent substitutions, modifications, etc. made by technicians in this field without any creative work within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a yield-increasing fully biodegradable controlled-release fertilizer, characterized in that: The specific steps are as follows: (1) Preparation of carrier-functional substance sustained-release complex: The functional substance, carrier and deionized water are reacted under mechanical stirring and heating conditions. After the reaction is completed, the complex is cooled to room temperature, filtered, washed with deionized water and freeze-dried to obtain a carrier-functional substance sustained-release complex. (2) blending and dissolving the carrier-functional substance sustained-release complex with a fully biodegradable resin and a solvent to obtain a coating solution; (3) Spraying the coating liquid onto the surface of the fertilizer particles to coat the fertilizer particles, thereby obtaining a yield-increasing functional fully biodegradable controlled-release fertilizer.

2. The method for preparing the yield-increasing functional fully biodegradable controlled-release fertilizer according to claim 1, characterized in that: The carrier in step (1) is one or more of carbon dots, C60, giant carbon tubes, flour, and porous glass powder, and the particle size of the carrier is 1-100nm; the functional substance is one or more of production-increasing amines, amine-increasing esters, amine esters, and synergistic amines.

3. The method for preparing the yield-increasing functional fully biodegradable controlled-release fertilizer according to claim 2, characterized in that: The carrier is a giant carbon tube with a particle size of 10-20 nm, and the functional substance is aminoethyl hexanoate.

4. The method for preparing the yield-increasing functional fully biodegradable controlled-release fertilizer according to any one of claims 1 to 3, characterized in that: The ratio of the functional substance, the carrier and the deionized water is (1-10) g: (90-99) g: (100-500) mL.

5. The method for preparing the yield-increasing functional fully biodegradable controlled-release fertilizer according to any one of claims 1 to 3, characterized in that: In step (1), the stirring rate is 10-60 rpm, the heating temperature is 40-90° C., the reaction time is 1-10 h, the freeze-drying temperature is -80--5° C., and the freeze-drying time is 1-10 h.

6. The method for preparing the yield-increasing functional fully biodegradable controlled-release fertilizer according to any one of claims 1 to 3, characterized in that: The fully biodegradable resin in step (2) is one or more of PHA, PVA, PHB, and PGA; the solvent is one or more of N,N-dimethylformamide, deionized water, carbon tetrachloride, ethyl acetate, toluene cyclohexanone, and hexafluoroisopropanol.

7. The method for preparing the yield-increasing functional fully biodegradable controlled-release fertilizer according to any one of claims 1 to 3, characterized in that: The ratio of the carrier-functional substance sustained-release complex, the fully biodegradable resin and the solvent in step (2) is (0.1-10) g: (90-99.9) g: 100 mL.

8. The method for preparing the yield-increasing functional fully biodegradable controlled-release fertilizer according to any one of claims 1 to 3, characterized in that: The blending and dissolving temperature is 10 to 120° C., and the blending and dissolving time is 1 to 10 hours.

9. The method for preparing the yield-increasing functional fully biodegradable controlled-release fertilizer according to any one of claims 1 to 3, characterized in that: In step (3), the particle size of the fertilizer particles is 2 to 4 mm, the amount of the fertilizer particles is 5.5 to 10 kg / time, the spray gun pressure is 0.5 to 200 MPa, the induced air temperature is 90 to 160° C., the coating time is 40 to 380 min, and the controlled-release fertilizer coating rate is 1.0 to 1.7 wt %.

10. A fully biodegradable controlled-release fertilizer with yield-increasing function prepared by the preparation method according to any one of claims 1 to 9.

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