A yield-increasing functional fully biodegradable controlled-release fertilizer and its preparation method

Abstract

The present invention relates to the field of new agricultural materials, and provides an increasing-production functional fully biodegradable controlled-release fertilizer and a preparation method thereof. A functional substance is loaded onto a carrier to obtain a carrier-functional substance slow-release composite with a slow-release function, and then the composite is blended and dissolved with a fully biodegradable resin and a solvent to obtain a coating solution. The coating solution is sprayed onto the surface of fertilizer particles to coat the fertilizer particles, thereby preparing an increasing-production functional fully biodegradable resin-coated controlled-release fertilizer. This fertilizer can enable the synchronous release of the increasing-production functional substance and the fertilizer nutrients, and maximize the nutrient utilization rate. The used fully biodegradable resin film material is finally degraded into carbon dioxide and water in the soil, which is green, environmentally friendly and pollution-free. It can replace traditional non-degradable polyethylene and polyurethane film materials, meets the requirements of the green and sustainable development of agriculture in China, and has important economic, social and ecological benefits.

Description

Technical Field

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

[0002] China is a large country in fertilizer application, and the fertilizer application amount ranks first in the world. At present, polymer-coated controlled-release fertilizers can improve the nutrient utilization rate, and the fertilizer utilization rate can be increased to 80%. However, currently commercialized controlled-release fertilizers are mostly prepared from non-degradable plastics such as polyethylene, sulfur-added resin, 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 polymer that can be decomposed into carbon dioxide and water by microorganisms in the natural environment. Currently, they have been applied in fields such as food packaging films, mulch films, and plastic bottles. Developing 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 the nutrient utilization rate, the improvement amplitude is limited, and there is still nearly 50% of fertilizer nutrients lost and wasted. Yield-increasing functional substances have the functions of promoting crop growth and increasing crop yield. Combining functional substances with coated controlled-release fertilizers to achieve the nutrient controlled-release property and functionality of controlled-release fertilizer products is an effective way to further improve the nutrient utilization rate.

[0004] In the prior art, the technical solution of Chinese Patent Application No. 201911380667.8 mixes powdery fertilizers and functional substances such as brassinolide, fulvic acid, humic acid, alginic acid, diethylaminoethanol caproate, etc. without any loading and slow-release treatment evenly, adds them to a granulator for granulation to obtain a functional slow / controlled-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 directly adds fulvic acid, a functional substance without any loading and slow-release treatment, to the surface of diammonium phosphate, and then obtains a functional polyurethane-coated controlled-release fertilizer 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 extract, diethylaminoethanol caproate, cyclic dipeptide, seaweed polysaccharide, amino oligosaccharide, etc. without any loading and slow-release treatment into the controlled-release fertilizer film material to develop a composite material-coated functional coated controlled-release fertilizer such as epoxy resin / polyurethane.

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

[0006] In addition, there are also literature reports on the technical solutions of coated controlled-release fertilizers. However, generally, multiple resins need to be compounded to meet the coating granulation process, and the corresponding film materials have 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 the requirement of full biodegradability of the film material cannot be met.

[0007] Therefore, the existing coated controlled-release fertilizers are difficult to meet the needs of agricultural development. Developing new coated controlled-release fertilizers has become the consensus of those skilled in the art. Summary of the Invention

[0008] To solve the problems that the film materials of coated controlled-release fertilizers in the prior art are difficult to degrade in the environment and the functional substances in the controlled-release fertilizers are released too fast, resulting in the inability to continuously play the role of promoting growth and increasing production throughout the growth period of crops, the present invention provides a production-increasing functional fully biodegradable controlled-release fertilizer and its preparation method. Using fully biodegradable resin as the film material to prepare the coated controlled-release fertilizer, the nutrient release functional period of the controlled-release fertilizer can be released completely within 1-4 months. After the release functional period, its film material can be degraded into carbon dioxide and water under the action of microorganisms in the soil, solving the problem of pollution caused by the difficult degradation of the film material of the coated controlled-release fertilizer in the soil. At the same time, the functional substances are loaded onto the carrier to obtain a carrier-functional substance slow-release complex with a slow-release function. Then, it is blended and dissolved with the fully biodegradable resin and the solvent to obtain a coating solution, and the coating solution is sprayed onto the surface of the fertilizer particles to coat the fertilizer particles to obtain a production-increasing functional fully biodegradable controlled-release fertilizer.

[0009] The present invention first provides a preparation method of a production-increasing functional fully biodegradable controlled-release fertilizer. The specific steps are as follows:

[0010] (1) Preparation of the carrier-functional substance slow-release complex: React the functional substance, the carrier, and deionized water under mechanical stirring and heating conditions. After the reaction is completed, cool to room temperature, and then perform suction filtration, washing with deionized water, and freeze-drying to obtain the carrier-functional substance slow-release complex;

[0011] (2) Dissolve the carrier-functional substance sustained-release complex, the fully biodegradable resin, and the solvent together to obtain a coating solution;

[0012] (3) Spray the coating solution onto the surface of the fertilizer particles to coat the fertilizer particles and obtain a yield-increasing functional fully biodegradable controlled-release fertilizer.

[0013] Preferably, in step (1), the carrier 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;

[0014] Preferably, in step (1), the functional substance is one or more of dicyclononane, ethylenediamine dihydrochloride, diethyl aminoethyl hexanoate, and synergistic amine.

[0015] Preferably, in step (1), the carrier is a giant carbon tube with a particle size of 10-20 nm.

[0016] On the premise that the specific surface area of the carrier is the same, the particle size of the carrier is closely related to the amount of functional substance that can be adsorbed by the carrier per unit mass. The larger the particle size, the less functional substance is adsorbed by the carrier per unit mass; the smaller the particle size, the more functional substance is adsorbed by the carrier per unit mass.

[0017] More preferably, the functional substance is diethyl aminoethyl hexanoate.

[0018] Diethyl aminoethyl hexanoate is a high-energy plant growth regulator with broad-spectrum and breakthrough effects, and its yield-increasing ability is the best among the above-mentioned functional substances; there are a large number of micropores, mesopores, and macropores inside the giant carbon tube, and its specific surface area is the largest among the above-mentioned carriers. Through the combination of the two, the best effect of slow release and yield increase can be achieved.

[0019] Preferably, in step (1), the ratio of the functional substance, the carrier, and deionized water is (1-10) g: (90-99) g: (100-500) mL;

[0020] More preferably, in step (1), the ratio of the functional substance, the carrier, and deionized water is 1 g: 99 g: 100 mL.

[0021] Preferably, 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 to -5 °C, and the freeze-drying time is 1-10 h.

[0022] Preferably, in step (2), the fully biodegradable resin is one or several of PHA, PVA, PHB, and PGA; the solvent is one or several of N,N-dimethylformamide, deionized water, carbon tetrachloride, ethyl acetate, toluene cyclohexanone, and hexafluoroisopropanol;

[0023] More preferably, the completely biodegradable resin described in step (2) is PHB, and the solvent is carbon tetrachloride.

[0024] PHB has a strong ability to block moisture and nutrients, and a strong ability to control the release of nutrients. Under the condition of reaching the same nutrient controlled 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.

[0025] Preferably, the ratio of the carrier-functional substance slow-release complex, the completely biodegradable resin and the solvent is (0.1-10) g: (90-99.9) g: 100 mL;

[0026] More preferably, the ratio of the carrier-functional substance slow-release complex, the completely biodegradable resin and the solvent is 5 g: 95 g: 100 mL.

[0027] Preferably, the co-blending and dissolving temperature is 10-120 °C, the co-blending and dissolving time is 1-10 h, the fertilizer particle size is 2-4 mm, the amount of fertilizer particles used is 5.5-10 kg / time, the spray gun pressure is 0.5-200 MPa, the induced air temperature is 90-160 °C, the coating time is 40-380 min, and the controlled release fertilizer coating rate is 1.0-1.7 wt% (calculated based on the carrier-functional substance slow-release complex + degradable resin).

[0028] In addition, the inventor provides a yield-increasing functional completely biodegradable controlled release fertilizer obtained by the above preparation method. The nutrient release functional period of the controlled release fertilizer can be released within 1-4 months. After the release functional period, its film material can be degraded into carbon dioxide and water under the action of microorganisms in the soil within several years, solving the problem of pollution caused by the difficult degradation of the film material of the coated controlled release fertilizer in the soil.

[0029] In addition, the present invention also claims to protect the yield-increasing functional completely biodegradable controlled release fertilizer prepared based on the above preparation method.

[0030] In summary, a yield-increasing functional completely biodegradable resin-coated controlled release fertilizer and its preparation method finally obtained in the present application have the following advantages compared with the prior art: (1) The film material of the controlled release fertilizer is completely biodegradable in farmland soil and will not cause soil white pollution problems; (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, and continuously acting on the entire growth period of the crop. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a photo of the film formed after pouring the controlled release fertilizer coating liquid described in Examples 1-3 of the present invention onto a glass plate and waiting for the solvent to volatilize, and then burying the film in the soil for 180 days.

[0032] Figure 2The controlled-release fertilizer coating liquid described in Examples 1-3 of the present invention was poured onto a glass plate, and after the solvent evaporated, a film was formed. The SEM images of the film surface before and 180 days after burying the film in the soil are shown.

[0033] Figure 3 The controlled-release fertilizer coating liquid described in Examples 1-3 of the present invention was poured onto a glass plate, and after the solvent evaporated, a film was formed. The AFM images of the film surface before and 180 days after burying the film in the soil are shown.

[0034] Figure 4 The controlled-release fertilizer coating liquid described in Examples 1-3 of the present invention was poured onto a glass plate, and after the solvent evaporated, a film was formed. The FTIR spectra of the film surface before and 180 days after burying the film in the soil are shown.

[0035] Figure 5 The controlled-release fertilizer coating liquid described in Examples 1-3 of the present invention was poured onto a glass plate, and after the solvent evaporated, a film was formed. The XPS spectra of the film surface before and 180 days after burying the film in the soil are shown. Detailed implementation manners

[0036] The technical solutions of the present invention will be further described below in conjunction with specific examples. These examples are only used to illustrate the technical solutions of the present invention in more detail and should not be construed as limiting the protection scope of the present invention.

[0037] DCPTA was purchased from Zhengzhou Chenjun Agrochemical Technology Co., Ltd., carbon dots were purchased from Hangzhou Xinqiao Biotechnology Co., Ltd., quick-acting urea was purchased from Huailu Hengsheng Chemical Co., Ltd., DA-6 was purchased from Jiangsu Caiwei Biotechnology Co., Ltd., C60 was purchased from Wuhan Karnos Technology Co., Ltd., DTA-6 was purchased from Hebi Quanfeng Biotechnology Co., Ltd., multi-walled carbon nanotubes were purchased from Jiangsu Xianfeng Nano Materials Technology Co., Ltd., DMPP was purchased from Zhongshan Dixin Chemical Co., Ltd., and porous glass powder was purchased from Donghai County Fucai Mineral Products Co., Ltd. Other substances or reagents used, if not otherwise specified, are all generally commercially available products.

[0038] The detection method of the coating rate was as follows: 10.0 g of coated urea was crushed with a hammer, then washed with deionized water to remove all urea components, and finally dried completely in an oven at 60 °C. Weighed with a ten-thousandth balance, and the average value was obtained by repeating three times, and then the final coating rate of the controlled-release urea could be calculated.

[0039] Example 1

[0040] First, a carbon dot-DCPTA slow-release complex was prepared, and the specific steps were as follows:

[0041] DCPTA, carbon dots, and deionized water were added to a three-necked flask, and the ratio was 2 g: 98 g: 300 mL, where the particle size of the carbon dots was 1-10 nm.

[0042] Heat to 40 °C for reaction under mechanical stirring at 10 rpm. The reaction time is 1 h. After the reaction, cool to room temperature, filter by suction, wash with deionized water, and freeze-dry at -5 °C for 1 h to obtain the carbon dot - dicyclononane slow-release complex.

[0043] Use the above carbon dot - dicyclononane slow-release complex as a raw material to prepare a yield-increasing functional fully biodegradable controlled-release urea. The specific steps are as follows:

[0044] Mix and dissolve the carbon dot - dicyclononane slow-release complex, PHA, and N,N-dimethylformamide in a ratio of 0.1 g:99.9 g:100 mL to obtain a coating solution. The temperature for mixing and dissolving is 10 °C, and the time for mixing and dissolving is 1 h.

[0045] Then spray the coating solution onto the surface of urea particles. The particle size of the urea particles is 2 mm, and the amount of urea particles used is 10 kg per time. Coating the urea particles, the spray gun pressure is 0.5 MPa, the air intake temperature is 160 °C, and the coating time is 40 min to obtain a yield-increasing functional biodegradable coated urea. The controlled-release urea coating rate is 1.0 wt%.

[0046] Comparative Example 1-1

[0047] A coated controlled-release urea, the preparation method of which is basically the same as that of the yield-increasing functional fully biodegradable controlled-release urea in Example 1. However, in Comparative Example 1-1, the carbon dot - dicyclononane slow-release complex is not used as a raw material, but dicyclononane is directly used as a raw material.

[0048] Specifically, mix dicyclononane, PHA, and N,N-dimethylformamide in a ratio of 0.002 g:99.9 g:100 mL, and the remaining steps are the same as those in Example 1.

[0049] Comparative Example 1-2

[0050] A coated controlled-release urea, the preparation method of which is basically the same as that of the yield-increasing functional fully biodegradable controlled-release urea in Example 1. However, in Comparative Example 1-2, the carbon dot - dicyclononane slow-release complex is not used as a raw material, and no functional substance is added to its raw materials.

[0051] Specifically, mix PHA and N,N-dimethylformamide in a ratio of 99.9 g:100 mL, and the remaining steps are the same as those in Example 1.

[0052] Comparative Example 1-3

[0053] A commercial ordinary coated controlled-release urea, specifically the polyurethane-coated blue film controlled-release urea produced by Shandong Agricultural University Fertilizer Industry Co., Ltd.

[0054] Comparative Examples 1-4

[0055] An instant-acting urea, purchased from Huailu Hengsheng Chemical Industry Co., Ltd., with a particle size of 2-4 mm and a nitrogen content of 46%.

[0056] Experimental Example 1-1

[0057] The release characteristics of the controlled-release urea were tested according to the international standard for controlled-release fertilizers ISO 18644. The 7-day release rate of urea refers to the cumulative nutrient release rate of urea in the fertilizer within 7 days, the 28-day release rate refers to the cumulative nutrient release rate of urea in the fertilizer within 28 days, and the release period refers to the number of days corresponding to the cumulative nutrient release rate of urea in the fertilizer reaching 80%.

[0058] The release characteristics of the functional substances in the controlled-release urea were tested according to the following method:

[0059] 10 g of the controlled-release fertilizer sample was placed into a microporous mesh bag and then put into a plastic bottle containing 200 mL of deionized water. Each treatment had 3 replicates, and then it was placed in an incubator at 25°C for cultivation. Samples were taken on the 1st, 3rd, 5th, 7th, 14th, 21st, and 28n (n≥1) days, and the release characteristics of the functional substances in the controlled-release urea film material were measured using ultraviolet-visible spectrophotometry.

[0060] The 7-day release rate of the functional substance refers to the cumulative nutrient release rate of the functional substance within 7 days, the 28-day release rate refers to the cumulative nutrient release rate of the functional substance within 28 days, and the release period refers to the number of days corresponding to the cumulative release rate of the functional substance reaching 80%.

[0061] Among them, since Comparative Examples 1-4 are instant-acting urea and do not have slow-release performance, their release characteristics were not tested.

[0062] As shown in Table 1, the yield-increasing functional fully biodegradable controlled-release urea product prepared in Example 1 had a 7-day release rate of urea of 9.13%, a 28-day release rate of 55.67%, and a nutrient controlled-release period of 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.

[0063] For the coated controlled-release urea in Comparative Example 1-1, the 7-day release rate of urea was 10.47%, the 28-day release rate was 50.43%, and the nutrient controlled-release period was 72.43 days; the 7-day release rate of the yield-increasing amine was 11.73%, the 28-day release rate was 61.27%; the nutrient controlled-release period was 47.82 days.

[0064] Therefore, compared with the coated controlled-release urea in Comparative Example 1-1, the yield-increasing functional fully biodegradable controlled-release urea product prepared in Example 1 had better synchronization in the release rate and nutrient controlled-release period of urea and the yield-increasing amine.

[0065] Pour the controlled-release fertilizer coating solution prepared in Example 1 onto a glass plate. After the solvent evaporates, a film is formed. After burying the film in the soil for 180 days, the macroscopic photograph of the film surface ( Figure 1 ), the SEM images of the film before and after burying in the soil ( Figure 2 ), and the AFM images of the film before and after burying in the soil ( Figure 3 ) can show that after 180 days of burying in the soil, the film is utilized by microorganisms in the soil, the surface has become uneven, and the film has become incomplete, and part of it has been eroded and utilized by microorganisms. By comparing the FTIR spectra of the film before and after burying in the soil ( Figure 4 ), it is found that the C-O single bond in the film becomes smaller. By comparing the XPS spectra of the film before and after burying in the soil ( Figure 5 ), it is found that the intensity of C1s in the film becomes smaller. All these indicate that microorganisms are eroding and utilizing the film by destroying the molecular structure of the film, and will eventually be slowly completely degraded into carbon dioxide and water, which are non-toxic and harmless.

[0066] Experimental Example 1-2

[0067] Using transplanted rice as the test crop, a field experiment on the preparation of a carbon dot - dicyclanil slow-release complex as a raw material for degradable coated controlled-release urea was carried out in Hedong District, Linyi City, Shandong Province from June 2023 to October 2023. The average yield of the experimental field in the previous five years was 6.10×10 3 kg / ha; the area of a single experimental plot is 30m 2 . The following examples and comparative examples all use three experimental plots for the experiment, and the final data is obtained by taking the average value.

[0068] The calculation of the yield increase rate uses Comparative Examples 1-4 as the control, and the specific calculation formula is as follows.

[0069] Yield increase rate (%) = (yield of other examples - yield of Comparative Examples 1-4) * 100% / yield increase of Comparative Examples 1-4 = net income of other examples - net income of Comparative Examples 1-4

[0070] The specific process is as follows: The test fertilizer is evenly spread into the test field as the base fertilizer at one time, and then plowed into the soil to a depth of 8 - 10 cm. Then transplant the rice seedlings, with a plant spacing of 12 cm and a row spacing of 24 cm. The nitrogen application rate is 300 kg / ha (pure nitrogen). The test nitrogen fertilizer is: The yield-increasing functional fully biodegradable controlled-release urea prepared in Example 1 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. The quick-acting urea in the test fertilizer (purchased from Huailu Hengsheng Chemical Co., Ltd., with a particle size of 2 - 4 mm and a nitrogen content of 46%) can provide the nitrogen required for the early growth of the transplanted rice seedlings; the controlled-release urea in the test fertilizer can provide the nitrogen required for the later growth of the transplanted rice seedlings. The phosphate fertilizer is selected as triple superphosphate (purchased from Yunnan Xingkun Chemical Co., Ltd., with a total phosphorus content of ≥46.0%), and the phosphorus application rate is 150 kg / ha (pure phosphorus); the potassium fertilizer is selected as potassium sulfate (purchased from Shandong Haihua Co., Ltd., with a potassium content of ≥50.0%), and the potassium application rate is 200 kg / ha (pure potassium). All nitrogen, phosphorus, and potassium fertilizers are applied as the base fertilizer at one time during rice transplantation and no additional topdressing is required. The field management measures for the transplanted rice are the same as those of the farmers' conventional management measures.

[0071] As shown in Table 2, the grain yield of the transplanted rice with the yield-increasing functional fully biodegradable controlled-release urea prepared in Example 1 under the above treatment is: 7.23×10 3 kg / ha, the total income is: 25305.00 yuan / ha, the net income is: 7991.28 yuan / ha, and the increased income is 4058.39 yuan / ha.

[0072] Comparative Example 1-1: By weight percentage, the PHA-coated controlled-release urea prepared in Comparative Example 1-1 (added with unloaded DCPTA) 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 kept consistent with the relevant treatments in Example 1 above. The grain yield of the transplanted rice is: 6.79×10 3 kg / ha, the total income is: 23765.00 yuan / ha, the net income is: 6517.60 yuan / ha, and the increased income is 2584.71 yuan / ha.

[0073] Comparative Example 1-2: By weight percentage, the PHA-coated controlled-release urea prepared in Comparative Example 1-2 (without adding any functional substances) 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 kept consistent with the relevant treatments in Example 1 above. The grain yield of the transplanted rice is: 6.53×10 3 kg / ha, the total income is: 22855.00 yuan / ha, the net income is: 5673.92 yuan / ha, and the increased income is 1741.03 yuan / ha.

[0074] Comparative Examples 1 - 3: By weight percentage, the commercial coated controlled-release urea described in Comparative Examples 1 - 3 (polyurethane-coated blue film controlled-release urea produced by Shandong Agricultural University Fertilizer Technology Co., Ltd.) accounts for 30% of the total urea mass (90 kg / ha), and the quick-acting urea accounts for 70% of the total urea mass (210 kg / ha); other factors are kept consistent with the relevant treatments in Example 1 above. The grain yield of transplanted rice is: 6.46×10 3 kg / ha, the total income is: 22,610.00 yuan / ha, the net income is: 5,163.64 yuan / ha, and the increased income is 1,230.75 yuan / ha.

[0075] Comparative Example 1 - 4: By weight percentage, the quick-acting urea accounts for 100% (the quick-acting urea is applied in two times, including basal application and topdressing. Among them, the basal application at the time of rice transplanting accounts for 70% of the total urea mass (210 kg / ha), and the topdressing 1 month after transplanting accounts for 30% of the total urea mass (90 kg / ha); phosphate fertilizer and potassium fertilizer are applied as basal fertilizers at one time); other factors are kept consistent with the relevant treatments in Example 1 above. The grain yield of transplanted rice is: 6.19×10 3 kg / ha, the total income is: 21,665.00 yuan / ha, and the net income is: 3,932.89 yuan / ha.

[0076] Compared with Comparative Examples 1 - 1, 1 - 2, 1 - 3, and 1 - 4, the transplanted rice treated with the scheme of Example 1 of this application has the largest yield (7.23×10³ kg / ha), the largest net income (7,991.28 yuan / ha), and the increased income is 4,058.39 yuan / ha.

[0077] Example 2

[0078] First, prepare a C60 - amine - ester slow - release complex, and the specific steps are as follows:

[0079] Add amine - ester, C60, and deionized water into a three - necked flask, and the ratio is 5 g:95 g:200 mL, where the particle size of C60 is 20 - 50 nm.

[0080] Heat to 60°C under mechanical stirring at 30 rpm for reaction, the reaction time is 4 h, after the reaction, cool to room temperature, filter by suction, wash with deionized water, and freeze - dry at - 20°C for 5 h to obtain the C60 - amine - ester slow - release complex.

[0081] Use the above - mentioned C60 - amine - ester slow - release complex as a raw material to prepare a yield - increasing functional fully biodegradable controlled - release urea, and the specific steps are as follows:

[0082] The C60-amino ester slow-release complex, PVA, and deionized water were blended and dissolved at 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.

[0083] Then, the coating solution was sprayed onto the surface of urea granules. The urea granules had a particle size of 2 mm, and the amount of urea granules used was 7.5 kg per time. The urea granules were coated. The spray gun pressure was 50 MPa, the air draft temperature was 110 °C, and the coating time was 120 min, obtaining a yield-increasing functional biodegradable coated urea. The controlled-release urea coating rate was 1.3 wt%.

[0084] Comparative Example 2-1

[0085] A coated controlled-release urea was prepared in a method basically the same as that for preparing the yield-increasing functional fully biodegradable controlled-release urea in Example 2. However, in Comparative Example 2-1, C60-amino ester slow-release complex was not used as a raw material, but amino ester was directly used as a raw material.

[0086] Specifically, amino ester, PVA, and deionized water were blended at 0.15 g: 97 g: 100 mL, and the remaining steps were the same as those in Example 2.

[0087] Comparative Example 2-2

[0088] A coated controlled-release urea was prepared in a method basically the same as that for preparing the yield-increasing functional fully biodegradable controlled-release urea in Example 2. However, in Comparative Example 2-2, C60-amino ester slow-release complex was not used as a raw material, and no functional substance was added to its raw materials.

[0089] Specifically, PVA and deionized water were blended at a ratio of 97 g: 100 mL, and the remaining steps were the same as those in Example 2.

[0090] Experimental Example 2-1

[0091] As shown in Table 1, the yield-increasing functional fully biodegradable controlled-release urea product prepared in Example 2 had a 7-day release rate of urea of 28.02%, a 28-day release rate of 64.03%, and a nutrient controlled-release period of 58.41 days; the 7-day release rate of amino ester was 22.40%, and the 28-day release rate was 55.90%; the nutrient controlled-release period was 63.98 days.

[0092] For the coated controlled-release urea of Comparative Example 2-1, the 7-day release rate of urea was 23.97%, the 28-day release rate was 63.07%, and the nutrient controlled-release period was 54.67 days; the 7-day release rate of amino ester was 32.97%, and the 28-day release rate was 70.93%; the nutrient controlled-release period was 35.58 days.

[0093] Therefore, compared with the coated controlled-release urea in Comparative Example 2-1, the yield-increasing functional fully biodegradable controlled-release urea product prepared in Example 2 has better synchronization in the release rates of urea and aminoethyl ester and the nutrient controlled-release period.

[0094] Pour the controlled-release fertilizer coating solution prepared in Example 2 onto a glass plate. After the solvent volatilizes, a film is formed. After burying the film in the soil for 180 days, the macroscopic photograph of the film surface ( Figure 1 ), the SEM images of the film before and after burying in the soil ( Figure 2 ), and the AFM images of the film before and after burying in the soil ( Figure 3 ) can show that after 180 days of burying in the soil, the film is utilized by microorganisms in the soil, and the surface has become uneven, and the film has become incomplete, and part of it has been eroded and utilized by microorganisms. By comparing the FTIR spectra of the film before and after burying in the soil ( Figure 4 ), it is found that the C-O single bond in the film becomes smaller. By comparing the XPS spectra of the film before and after burying in the soil ( Figure 5 ), it is found that the intensity of C1s in the film becomes smaller. All these indicate that microorganisms are eroding and utilizing the film by destroying the molecular structure of the film, and will eventually be slowly completely degraded into carbon dioxide and water, which are non-toxic and harmless.

[0095] Experimental Example 2-2

[0096] Using transplanted rice as the test crop, a field experiment on the degradation-coated controlled-release urea prepared with the C60-aminoethyl ester slow-release complex as the raw material was carried out in Hedong District, Linyi City, Shandong Province from June 2023 to October 2023. The average yield of the test field in the previous five years was 6.10×10 3 kg / ha; the area of a single test plot is 30 m 2 . The following examples and comparative examples all use three test plots for the experiment, and the final data are obtained by taking the average value.

[0097] Yield increase rate (%) = (yield of other examples - yield of Comparative Examples 1-4) * 100% / yield of Comparative Examples 1-4 Income increase = net income of other examples - net income of Comparative Examples 1-4

[0098] The specific process is as follows: The test fertilizer is evenly spread as base fertilizer into the test field at one time, and then plowed into the soil to a depth of 8 - 10 cm. Then transplant the rice seedlings with a plant spacing of 12 cm and a row spacing of 24 cm. The nitrogen application rate is 300 kg / ha (pure nitrogen). The test nitrogen fertilizer is: The yield-increasing functional fully biodegradable controlled-release urea prepared in Example 2 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. The quick-acting urea in the test fertilizer (purchased from Huailu Hengsheng Chemical Co., Ltd., particle size 2 - 4 mm, nitrogen content 46%) can provide the nitrogen required for the early growth of transplanted rice seedlings; the controlled-release urea in the test fertilizer can provide the nitrogen required for the later growth of transplanted rice seedlings. The phosphate fertilizer selected is triple superphosphate (purchased from Yunnan Xingkun Chemical Co., Ltd., total phosphorus content ≥ 46.0%), and the phosphorus application rate is 150 kg / ha (pure phosphorus); the potassium fertilizer selected is potassium sulfate (purchased from Shandong Haihua Co., Ltd., potassium content ≥ 50.0%), and the potassium application rate is 200 kg / ha (pure potassium). All nitrogen, phosphorus, and potassium fertilizers are applied as base fertilizer at one time during rice transplanting and no topdressing is required. The field management measures for transplanted rice are the same as those of farmers' conventional management measures.

[0099] As shown in Table 2, the grain yield of transplanted rice with the yield-increasing functional fully biodegradable controlled-release urea prepared in Example 2 under the above treatment is: 7.51×10 3 kg / ha, the total income is: 26285.00 yuan / ha, the net income is: 8938.12 yuan / ha, and the increased income is 5005.23 yuan / ha.

[0100] Comparative Example 2 - 1: By weight percentage, the PVA-coated controlled-release urea prepared in Comparative Example 2 - 1 (added with 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 kept consistent with the relevant treatments in Example 2 above. The grain yield of transplanted rice is: 6.91×10 3 kg / ha, the total income is: 24185.00 yuan / ha, the net income is: 6904.44 yuan / ha, and the increased income is 2971.55 yuan / ha.

[0101] Comparative Example 2 - 2: By weight percentage, the PVA-coated controlled-release urea prepared in Comparative Example 2 - 2 (without adding any functional substances) 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 kept consistent with the relevant treatments in Example 2 above. The grain yield of transplanted rice is: 6.82×10 3 kg / ha, the total income is: 23870.00 yuan / ha, the net income is: 6655.76 yuan / ha, and the increased income is 2722.87 yuan / ha.

[0102] Compared with Comparative Examples 2-1, 2-2, 1-3, and 1-4, the yield of transplanted rice processed by the solution of Example 2 of this application is the largest (7.51×10 3 kg / ha), the net income is the largest (8938.12 yuan / ha), and the increased income is 5005.23 yuan / ha.

[0103] Example 3

[0104] First, a multi-walled carbon nanotube - diethyl aminoethyl hexanoate slow-release complex is prepared, and the specific steps are as follows:

[0105] Add diethyl aminoethyl hexanoate, multi-walled carbon nanotubes, and deionized water to a three-necked flask, with a ratio of 1 g:99 g:100 mL, and the particle size of the multi-walled carbon nanotubes is 10 - 20 nm.

[0106] Heat to 75°C for reaction under mechanical stirring at 50 rpm, with a reaction time of 8 h. After the reaction, cool to room temperature, perform suction filtration and wash with deionized water, and freeze-dry at -50°C for 7 h to obtain the multi-walled carbon nanotube - diethyl aminoethyl hexanoate slow-release complex.

[0107] Use the above-mentioned multi-walled carbon nanotube - diethyl aminoethyl hexanoate slow-release complex as a raw material to prepare a yield-increasing functional fully biodegradable controlled-release urea, and the specific steps are as follows:

[0108] Mix and dissolve the multi-walled carbon nanotube - diethyl aminoethyl hexanoate slow-release complex, PHB, and carbon tetrachloride in a ratio of 5 g:95 g:100 mL to obtain a coating solution. The temperature for mixing and dissolving is 70°C, and the time for mixing and dissolving is 6 h.

[0109] Then spray the coating solution onto the surface of urea particles. The particle size of the urea particles is 3 mm, the dosage of the urea particles is 6.5 kg / time, coat the urea particles, with a spray gun pressure of 100 MPa, an induced air temperature of 90°C, and a coating time of 220 min to obtain a yield-increasing functional biodegradable coated urea, and the controlled-release urea coating rate is 1.5 wt%.

[0110] Comparative Example 3-1

[0111] A coated controlled-release urea, the preparation method of which is basically the same as that of the yield-increasing functional fully biodegradable controlled-release urea in Example 3. However, in Comparative Example 3-1, the multi-walled carbon nanotube - diethyl aminoethyl hexanoate slow-release complex is not used as a raw material, but diethyl aminoethyl hexanoate is directly used as a raw material.

[0112] Specifically, diethyl aminoethyl hexanoate, PHB, and carbon tetrachloride are mixed in a ratio of 0.05 g:95 g:100 mL, and the remaining steps are the same as those in Example 3.

[0113] Comparative Example 3-2

[0114] A coated controlled-release urea, the preparation method of which is basically the same as that of the yield-increasing functional fully biodegradable controlled-release urea prepared in Example 3, but in Comparative Example 3-2, the giant carbon tube-dichlorophenoxyacetic acid slow-release complex is not used as a raw material, and no functional substances are added to its raw materials.

[0115] 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.

[0116] Experimental Example 3-1

[0117] As shown in Table 1, the yield-increasing functional fully biodegradable controlled-release urea product prepared in Example 3, 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 dichlorophenoxyacetic acid was: 2.10%, the 28-day release rate was: 26.43%; the nutrient controlled-release period was: 106.67 days.

[0118] For the coated controlled-release urea of Comparative Example 3-1, the 7-day release rate of urea was: 1.10%, the 28-day release rate was 20.53%, and the nutrient controlled-release period was: 89.50 days; the 7-day release rate of dichlorophenoxyacetic acid was: 4.40%, the 28-day release rate was: 37.53%; the nutrient controlled-release period was: 49.55 days.

[0119] Therefore, compared with the coated controlled-release urea of Comparative Example 3-1, the yield-increasing functional fully biodegradable controlled-release urea product prepared in Example 3 has better synchronization in the release rate and nutrient controlled-release period of urea and dichlorophenoxyacetic acid.

[0120] Pour the controlled-release fertilizer coating solution prepared in Example 3 onto a glass plate. After the solvent volatilizes, a film is formed. After the film is buried in the soil for 180 days, the macroscopic photograph of the film surface ( Figure 1 ), the SEM images of the film before and after being buried in the soil ( Figure 2 ), and the AFM images of the film before and after being buried in the soil ( Figure 3 ) can show that after being buried in the soil for 180 days, the film is utilized by microorganisms in the soil, the surface has become uneven, and the film has become incomplete, and part of it has been eroded and utilized by microorganisms. By comparing the FTIR spectra of the film before and after being buried in the soil ( Figure 4 ), it is found that the C-O single bond in the film becomes smaller. By comparing the XPS spectra of the film before and after being buried in the soil ( Figure 5 ), it is found that the intensity of C1s in the film becomes smaller. All these indicate that microorganisms are eroding and utilizing the film by destroying the molecular structure of the film, and will eventually be slowly completely degraded into carbon dioxide and water, which are non-toxic and harmless.

[0121] Experimental Example 3-2

[0122] Using transplanted rice as the test crop, a field experiment on degradable coated controlled-release urea prepared from a giant carbon tube-dichlorophenoxyacetic acid slow-release complex was conducted in Hedong District, Linyi City, Shandong Province from June 2023 to October 2023. The average yield of the experimental field in the previous five years was 6.10×10 3 kg / ha; the area of a single experimental plot was 30m 2 , and the following examples and comparative examples were all tested using three experimental plots, and the final data were obtained by taking the average value.

[0123] Yield increase rate (%) = (yield of other examples - yield of Comparative Examples 1-4) * 100% / yield of Comparative Examples 1-4. Income increase = net income of other examples - net income of Comparative Examples 1-4

[0124] The specific process is as follows: The test fertilizer is spread into the experimental field as a base fertilizer at one time, and then the test fertilizer is plowed into the soil to a depth of 8-10 cm, and then transplanted. The plant spacing of the transplanted rice is 12 cm, the row spacing is 24 cm, and the nitrogen application rate is 300 kg / ha (in terms of pure nitrogen). The test nitrogen fertilizer is: the yield-increasing functional fully biodegradable controlled-release urea prepared in Example 3 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. The quick-acting urea in the test fertilizer (purchased from Hualu Hengsheng Chemical Co., Ltd., particle size 2-4 mm, nitrogen content 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 later growth of transplanted rice. The phosphate fertilizer is selected as triple superphosphate (purchased from Yunnan Xingkun Chemical Co., Ltd., total phosphorus content ≥ 46.0%), and the phosphorus application rate is 150 kg / ha (in terms of pure phosphorus); the potassium fertilizer is selected as potassium sulfate (purchased from Shandong Haihua Co., Ltd., potassium content ≥ 50.0%), and the potassium application rate is 200 kg / ha (in terms of pure potassium). All nitrogen, phosphorus, and potassium fertilizers are applied as base fertilizers at one time during rice transplanting and no additional topdressing is required. The field management measures for transplanted rice are the same as those of farmers' conventional management measures.

[0125] As shown in Table 2, the grain yield of transplanted rice under the above treatment with the yield-increasing functional fully biodegradable controlled-release urea prepared in Example 3 was: 8.54×10 3 kg / ha, the total income was: 29,890.00 yuan / ha, the net income was: 12,563.02 yuan / ha, and the income increase was 8,630.13 yuan / ha.

[0126] Comparative Example 3-1: By weight percentage, the PHB-coated controlled-release urea prepared in Comparative Example 3-1 (added with unloaded dichlorophenoxyacetic acid) 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 kept consistent with the relevant treatments in Example 3 above. The grain yield of transplanted rice was: 7.03×10 3kg / ha, the total income is: 24,605.00 yuan / ha, the net income is: 7,344.34 yuan / ha, and the increased income is 3,411.45 yuan / ha.

[0127] Comparative Example 3-2: By weight percentage, the PHB-coated controlled-release urea prepared in Comparative Example 3-2 (without adding any functional substances) 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 kept consistent with the relevant treatments in Example 3 above. The grain yield of transplanted rice is: 6.94×10 3 kg / ha, the total income is: 24,290.00 yuan / ha, the net income is: 7,095.66 yuan / ha, and the increased income is 3,162.77 yuan / ha.

[0128] Compared with Comparative Examples 3-1, 3-2, 1-3, and 1-4, the transplanted rice treated with the scheme of Example 3 of this application has the largest yield (8.54×10 3 kg / ha), the largest net income (12,563.02 yuan / ha), and the increased income of 8,630.13 yuan / ha.

[0129] Example 4

[0130] First, prepare a porous glass powder-synergistic amine slow-release complex, and the specific steps are as follows:

[0131] Add synergistic amine, porous glass powder, and deionized water to a three-necked flask, with a ratio of 10 g: 90 g: 500 mL, and the particle size of the porous glass powder is 50-100 nm.

[0132] Heat to 90 °C for reaction under mechanical stirring at 60 rpm, the reaction time is 10 h, cool to room temperature after the reaction, filter by suction, wash with deionized water, and freeze-dry at -80 °C for 10 h to obtain a porous glass powder-synergistic amine slow-release complex.

[0133] Use the above-mentioned porous glass powder-synergistic amine slow-release complex as a raw material to prepare an increasing-production functional fully biodegradable controlled-release urea, and the specific steps are as follows:

[0134] Mix and dissolve the porous glass powder-synergistic amine slow-release complex, PGA, and ethyl acetate according to a ratio of 10 g: 90 g: 100 mL to obtain a coating solution, the mixing and dissolving temperature is 70 °C, and the mixing and dissolving time is 10 h.

[0135] Then the coating solution was sprayed onto the surface of urea particles with a particle size of 4 mm and a dosage of 5.5 kg / time. The urea particles were coated with a spray gun pressure of 200 MPa, an induced air temperature of 140 °C, and a coating time of 380 min, obtaining a yield-increasing functional biodegradable coated urea with a controlled-release urea coating rate of 1.7 wt%.

[0136] Comparative Example 4-1

[0137] A coated controlled-release urea was prepared by a method basically the same as that for preparing the yield-increasing functional fully biodegradable controlled-release urea in Example 4. However, in Comparative Example 4-1, porous glass powder-synergist amine sustained-release complex was not used as a raw material, but synergist amine was directly used as a raw material.

[0138] Specifically, synergist amine, PGA, and ethyl acetate were blended at a ratio of 1 g: 90 g: 100 mL, and the remaining steps were the same as those in Example 4.

[0139] Comparative Example 4-2

[0140] A coated controlled-release urea was prepared by a method basically the same as that for preparing the yield-increasing functional fully biodegradable controlled-release urea in Example 4. However, in Comparative Example 4-2, porous glass powder-synergist amine sustained-release complex was not used as a raw material, and no functional substance was added to its raw materials.

[0141] Specifically, PGA and ethyl acetate were blended at a ratio of 90 g: 100 mL, and the remaining steps were the same as those in Example 4.

[0142] Experimental Example 4-1

[0143] As shown in Table 1, the yield-increasing functional fully biodegradable controlled-release urea product prepared in Example 4 had a 7-day release rate of urea of 4.73%, a 28-day release rate of 30.40%, and a nutrient controlled-release period of 102.72 days; the 7-day release rate of synergist amine was 2.73%, the 28-day release rate was 24.13%; and the nutrient controlled-release period was 111.25 days.

[0144] For the coated controlled-release urea of Comparative Example 4-1, the 7-day release rate of urea was 2.27%, the 28-day release rate was 15.10%, and the nutrient controlled-release period was 99.20 days; the 7-day release rate of synergist amine was 2.75%, the 28-day release rate was 33.47%; and the nutrient controlled-release period was 53.24 days.

[0145] Therefore, compared with the coated controlled-release urea of Comparative Example 4-1, the yield-increasing functional fully biodegradable controlled-release urea product prepared in Example 4 had better synchronization in the release rate and nutrient controlled-release period of urea and synergist amine.

[0146] Experimental Example 4-2

[0147] Using transplanted rice as the test crop, a field experiment on degradable coated controlled-release urea prepared from a porous glass powder-synergistic amine slow-release complex was conducted in Hedong District, Linyi City, Shandong Province from June 2023 to October 2023. The average yield of the experimental field in the previous five years was 6.10×10 3 kg / ha; the area of a single experimental plot was 30m 2 . The following examples and comparative examples were all tested with three experimental plots, and the final data were obtained by taking the average value.

[0148] Yield increase rate (%) = (yield of other examples - yields of Comparative Examples 1-4) * 100% / yields of Comparative Examples 1-4 Income increase = net income of other examples - net income of Comparative Examples 1-4

[0149] The specific process is as follows: The test fertilizer is evenly spread into the experimental field as the base fertilizer at one time, and then the test fertilizer is plowed into the soil to a depth of 8-10 cm, and then transplanted. The plant spacing of the transplanted rice is 12 cm, the row spacing is 24 cm, and the nitrogen application rate is 300 kg / ha (in terms of pure nitrogen). The test nitrogen fertilizer is: the yield-increasing functional fully biodegradable controlled-release urea prepared in Example 4 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. The quick-acting urea in the test fertilizer (purchased from Huailu Hengsheng Chemical Co., Ltd., particle size 2-4 mm, nitrogen content 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 later growth of transplanted rice. The phosphate fertilizer is selected as triple superphosphate (purchased from Yunnan Xingkun Chemical Co., Ltd., total phosphorus content ≥ 46.0%), and the phosphorus application rate is 150 kg / ha (in terms of pure phosphorus); the potassium fertilizer is selected as potassium sulfate (purchased from Shandong Haihua Co., Ltd., potassium content ≥ 50.0%), and the potassium application rate is 200 kg / ha (in terms of pure potassium). All nitrogen, phosphorus, and potassium fertilizers are applied as the base fertilizer at one time during rice transplanting and no additional topdressing is required. The field management measures for transplanted rice are the same as those of farmers' conventional management measures.

[0150] As shown in Table 2, the grain yield of transplanted rice under the above treatment with the yield-increasing functional fully biodegradable controlled-release urea prepared in Example 4 was: 8.02×10 3 kg / ha, the total income was: 28,070.00 yuan / ha, the net income was: 10,776.18 yuan / ha, and the income increase was 6,843.29 yuan / ha.

[0151] Comparative Example 4-1: By weight percentage, the PGA-coated controlled-release urea prepared in Comparative Example 4-1 (added with synergistic amine without loading treatment) accounted for 30% of the total mass of urea (90 kg / ha), and the quick-acting urea accounted for 70% of the total mass of urea (210 kg / ha); other factors were kept consistent with the relevant treatments in Example 4 above. The grain yield of transplanted rice was: 7.05×10 3 kg / ha, the total income was: 24,675.00 yuan / ha, the net income was: 7,447.50 yuan / ha, and the increased income was: 3,514.61 yuan / ha.

[0152] Comparative Example 4-2: By weight percentage, the PGA-coated controlled-release urea prepared in Comparative Example 4-2 (without adding any functional substances) accounted for 30% of the total mass of urea (90 kg / ha), and the quick-acting urea accounted for 70% of the total mass of urea (210 kg / ha); other factors were kept consistent with the relevant treatments in Example 4 above. The grain yield of transplanted rice was: 6.87×10 3 kg / ha, the total income was: 24,045.00 yuan / ha, the net income was: 6,883.82 yuan / ha, and the increased income was: 2,950.93 yuan / ha.

[0153] Compared with Comparative Examples 4-1, 4-2, 1-3, and 1-4, the transplanted rice treated with the scheme of Example 4 of this application had the highest yield (8.02×10 3 kg / ha), the highest net income (10,776.18 yuan / ha), and the increased income was 6,843.29 yuan / ha.

[0154] Table 1 7-day release rate, 28-day release rate and nutrient controlled-release period of the coated controlled-release fertilizer in the present invention

[0155]

[0156]

[0157] Table 2 Yield, income, etc. of rice after applying the fertilizers of the examples and comparative examples to transplanted rice in Linyi

[0158]

[0159] Note: The purchase price of paddy is 3.5 yuan / kg, and 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 expenditure: 25 yuan / mu / time for both base fertilizer and top dressing, pesticide application (60 yuan / mu), and field management (80 yuan / mu).

[0160] It can be seen that Example 3 in the above examples has the best effect and can be widely promoted and applied.

[0161] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any equivalent replacement, modification, etc. made by those skilled in the art within the spirit and principle of the present invention without any creative work shall be included within the protection scope of the present invention.

Claims

1. A preparation method of an increasing-yield functional 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. The carrier 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; the functional substance is one or more of production-increasing amines, production-increasing amine esters, aminoethyl esters, and synergistic amines; The ratio of the functional substance, the carrier and the deionized water is (1-10) g: (90-99) g: (100-500) mL; (2) blending and dissolving the carrier-functional substance sustained-release complex with a fully biodegradable resin and a solvent to obtain a coating solution; The fully biodegradable resin is one or more of PHA, PVA, PHB, and PGA; (3) Spraying the coating liquid onto the surface of the fertilizer particles to coat the fertilizer particles and obtain a fully biodegradable controlled-release fertilizer with yield-increasing functionality.

2. The preparation method of the yield-increasing functional fully biodegradable controlled-release fertilizer according to claim 1, wherein, The carrier is a giant carbon tube with a particle size of 10-20 nm, and the functional substance is aminoethyl hexanoate.

3. The preparation method of the yield-increasing functional fully biodegradable controlled-release fertilizer according to claim 1 or 2, characterized in that 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.

4. The preparation method of the yield-increasing functional fully biodegradable controlled-release fertilizer according to claim 1 or 2, characterized in that, The solvent in step (2) is one or more of N,N-dimethylformamide, deionized water, carbon tetrachloride, ethyl acetate, toluene cyclohexanone, and hexafluoroisopropanol.

5. The preparation method of the yield-increasing functional fully biodegradable controlled-release fertilizer according to claim 1 or 2, 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.

6. The preparation method of the yield-increasing functional fully biodegradable controlled-release fertilizer according to claim 1 or 2, characterized in that, The blending and dissolving temperature is 10 to 120° C., and the blending and dissolving time is 1 to 10 hours.

7. The preparation method of the yield-increasing functional fully biodegradable controlled-release fertilizer according to claim 1 or 2, characterized in that, In step (3), the particle size of the fertilizer particles is 2 to 4 mm, the amount of 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%.

8. A fully biodegradable controlled-release fertilizer with yield-increasing function prepared by the preparation method according to any one of claims 1 to 7.

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