A high water-resistance intelligent fully biodegradable bag-controlled fertilizer and preparation method thereof

Abstract

The present invention relates to the field of new agricultural materials, and specifically provides a highly water-resistant intelligent fully biodegradable bag controlled fertilizer and a preparation method thereof. The fertilizer is packaged in a fully biodegradable bag to achieve controlled nutrient release. Compared with the coated controlled-release fertilizer, the amount of film material is reduced by 3-6 times, solving the problem that the farmland controlled-release fertilizer film material is difficult to degrade in the soil and has high cost; the water-explosive inorganic nanoparticles coated with a compatible material are added to the controlled-release film material to obtain an intelligent fully biodegradable bag controlled fertilizer with high water-resistant function in the early stage and sensitive to moisture and timed explosion in the later stage. By accurately controlling the thickness of the coated barrier layer, the time for water to enter the barrier layer and the controlled release time of nutrients (1-3 months) can be accurately controlled, and intelligent release can be achieved at different growth stages of crops, greatly improving the nutrient utilization rate of the controlled-release fertilizer. And the water-explosive nanoparticles will produce growth-promoting gas when they explode in water, which can promote the growth and development of crops. The present invention has simple processing technology, low energy consumption and high efficiency.

Description

Technical Field

[0001] The invention belongs to the field of new agricultural materials and new fertilizers, and specifically relates to a highly water-resistant intelligent fully biodegradable bag-controlled fertilizer and a preparation method thereof. Background Art

[0002] Slow-release fertilizers have the advantages of improving nutrient utilization, saving labor and time, reducing fat and increasing efficiency. The promotion and application of slow-release fertilizers is of great significance to the increase and stability of my country's agricultural grain production. At present, the annual production and sales volume of coated controlled-release fertilizers in my country exceeds 21 million tons, and the agricultural application amount can reach 3.15 million tons, with a cumulative promotion area of ​​about 525 million mu.

[0003] However, traditional coated controlled-release fertilizers have problems such as difficult degradation of film materials and high costs, which limit the promotion and application of slow-release fertilizers. The traditional controlled-release fertilizer industry is in urgent need of green transformation and upgrading. At present, the film material usage of traditional petrochemical resin coated controlled-release fertilizers such as polyethylene, polyurethane, and epoxy resin is about 3.0%. Compared with traditional coated controlled-release fertilizers, the film material usage of bag-sealed controlled-release fertilizers can be reduced by 3-6 times to only 0.5-1.0%. The price of petrochemical resins is 10,000-15,000 yuan / ton, and the price of fully biodegradable resins is 12,000-13,000 yuan / ton. The prices of the two are basically the same. Therefore, the production cost of fully biodegradable bag-controlled fertilizers can be greatly reduced by significantly reducing the film material usage by 3-6 times. The development of low-cost bag-sealed fully biodegradable controlled-release fertilizers has important economic, social and ecological benefits, and has great prospects for development and utilization.

[0004] However, in actual applications, we found that biodegradable bag-controlled fertilizers still have the disadvantages of poor water-blocking performance of the membrane material, imprecise nutrient release, and asynchrony with crop absorption. At different stages of crop growth, the demand for nutrients is inconsistent. Some specific growth periods require a large amount of nutrients, while in other periods the demand for nutrients is not urgent. Traditional conventional controlled-release fertilizers release nutrients slowly and evenly, which will cause nutrient waste in the stage when crops require less fertilizer, and cannot meet the demand of crops for fertilizer nutrients in the stage when crops require a lot of fertilizer. Therefore, it is urgent to develop an intelligent fully biodegradable bag-controlled fertilizer with both high water resistance and moisture-sensitive intelligent blasting function, so that the nutrient release of this type of fertilizer is synchronized with crop absorption, thereby maximizing nutrient utilization efficiency.

[0005] At present, the patents related to rupture release are mainly concentrated in the field of drug release: 200710037076.1, 201310178489.7, 201310426145.3, 201710664741.3, 201210081020.7, 201610679565.6, 201610998279.6, 202111648310.0. Analyzing the above patents, they have common shortcomings: (1) The membrane material is extremely unstable when it comes into contact with water. After being soaked in water for a short time, the membrane shell will disintegrate, and the functional time of the product is very short, usually only a few hours. (2) The principle of membrane rupture is unclear, and the purpose of precise controlled release cannot be achieved. In essence, it is not intelligent timed release, and it is more appropriate to describe it as "sustained release". Summary of the invention

[0006] The technical problems to be solved by the present invention are: (1) solving the problem that controlled-release fertilizer films for farmland are difficult to degrade in the soil environment and the film materials have high costs; (2) solving the problem that controlled-release fertilizer films have poor water barrier properties and inaccurate nutrient release, so that nutrient release is synchronized with crop absorption and nutrient utilization efficiency is maximized.

[0007] The design ideas of the present invention are as follows: (1) Develop a fully biodegradable bag-controlled fertilizer using fully biodegradable film materials. The film materials are fully biodegradable in the soil, and the cost of the film materials is reduced by 3-6 times, solving the problem of difficult degradation and high cost of controlled-release fertilizer film materials. (2) Add inorganic nanoparticles that have been coated and modified with compatible materials to degradable controlled-release film materials to obtain an intelligent fully biodegradable bag-controlled fertilizer that has a high water-blocking function in the early stage and is sensitive to moisture and explodes at a fixed time in the later stage. In this way, in the early stage when the crop's demand for nutrients is not obvious, nutrients are not released or released less, and in the later growth stage when the crop needs a lot of fertilizer, it breaks and releases, and the nutrients are released in large quantities in a short time, thereby achieving the purpose of maximizing the efficiency of crop utilization of nutrients and solving the problem of poor water-blocking performance and inaccurate nutrient release of controlled-release fertilizer film materials.

[0008] The basic principle of the present invention is as follows: a barrier layer formed by a compatible material is coated on the surface of water-explosive inorganic nanoparticles, and the barrier layer has a certain barrier capacity for water and nutrients. The coated nanoparticles are added to a fully biodegradable film material to prepare a fully biodegradable bag-controlled fertilizer. In the early stage of nutrient release of this type of fertilizer, the coated nanoparticles in the film material play a role in blocking water entry and nutrient dissolution, achieving a high barrier effect in the early stage; but in the late stage of nutrient release of this type of fertilizer, when water enters the interior through the micropores in the barrier layer and contacts the water-explosive inorganic nanoparticles coated with the compatible material, due to the barrier layer formed by the compatible material, the contact time between water and the water-explosive nanoparticles is inconsistent, and a rapid reaction will occur at the moment of contact, instantly generating a large amount of gas, similar to a nano "micro bomb", and the volume expands rapidly, thereby breaking the film material, and the internal nutrients can be quickly released to supply the nutrient needs of crops.

[0009] In order to achieve the purpose of timed rupture and precise release in the present invention, a barrier layer is formed by coating the surface of the water-explosive inorganic nanoparticles with compatible materials of different thicknesses. Since the barrier layer has different barrier capabilities for water, water will enter the interior at different times to contact the water-explosive inorganic nanoparticles. At the moment of contact between water and the nanoparticles, a large amount of gas will be rapidly generated to blast the fully biodegradable controlled-release membrane material, and nutrients will be quickly released to supply crop needs. Therefore, by precisely controlling the thickness of the coated barrier layer, the time when water enters the barrier layer and the controlled-release time of nutrients can be precisely controlled, and the nutrients can be intelligently released at different growth stages of the crop, achieving the purpose of topdressing at different growth stages of the crop, and no longer requiring artificial topdressing, saving labor and time, and maximizing the nutrient utilization rate of the controlled-release fertilizer.

[0010] The present invention first provides a method for preparing a highly water-resistant intelligent fully biodegradable bag-controlled fertilizer, comprising the following steps:

[0011] 1) dissolving a compatible material A in a solvent B, then adding nano-scale water-explosive particles C, and subjecting the mixture to mechanical stirring and vacuum drying to obtain modified nano-particles D coated with the compatible material;

[0012] 2) The modified nanoparticles D coated with the compatible material and the fully biodegradable resin E are blended, and the fully biodegradable controlled release membrane F is prepared through granulation and film blowing processes;

[0013] 3) The fully biodegradable controlled-release film material F is used to heat-seal and encapsulate the fertilizer G to obtain a highly water-resistant intelligent fully biodegradable bag-controlled fertilizer H.

[0014] Preferably, the compatible material A is one or more of natural rubber, PET, PHB, and PLLA;

[0015] Preferably, the solvent B is one or more of gasoline, trichlorobutane, butylene oxide, cyclohexanone, and isopropane;

[0016] Preferably, the nano-scale water-explosive particles C are one or more of sodium, potassium, barium, rubidium, strontium, cesium or their hydrides or peroxides, or magnesium nitride and calcium carbide;

[0017] Preferably, in the step 1), the vacuum drying pressure is 0.01-0.1 MPa, the vacuum drying temperature is 30-90° C., the mechanical stirring rate is 10-1000 r / min, and the usage ratio of the compatible material A, the solvent B and the nano-scale water-explosive particles C is (0.1-1) g: (100-500) mL: (1-10) g;

[0018] Preferably, the particle size of the modified nanoparticle D is 1-1000 nm, and the coating layer thickness is 1-50 nm;

[0019] Preferably, the fully biodegradable resin E is one or more of PHA, PCL, PBSA, and PGA;

[0020] Preferably, the specific process for preparing the fully biodegradable controlled release membrane F in step 2) is as follows: the modified nanoparticles D and the fully biodegradable resin E are blended in a high-speed mixer at a blending ratio of (0.1-8) g: (100-200) g for 1-20 min at a mixing rate of 50-1000 r / min, and then the mixture is granulated by a twin-screw extruder to obtain a composite masterbatch at a feed rate of 50-600 g / min and a screw speed of 100-800 rpm. The temperature from the material port to the die head is set to (80-220) / (80-220) / (90-230) / (90-230) / (70-210) / (70-210) / (60-200)°C. Finally, the composite masterbatch is blown into film by a single-screw film blowing machine. The die head temperature is set to: (120-200) / (130-220) / (125-210) / (110-190) / (100-190)°C, and the film thickness is 5-10μm.

[0021] Preferably, the fertilizer G is one or more of granular fertilizer, powder fertilizer, liquid fertilizer, organic fertilizer, etc.

[0022] Preferably, the temperature parameter of the heat sealing in step 3) is 50-200°C, the mass ratio of the fully biodegradable controlled-release membrane material F to the highly water-resistant intelligent fully biodegradable bag controlled-release fertilizer H is (0.06-1)g:(6-200)g, and the release time of the finally obtained controlled-release fertilizer is 1-3 months.

[0023] In addition, the inventor also claims to protect the high water-resistance intelligent fully biodegradable bag-controlled fertilizer prepared by the above method.

[0024] The highly water-resistant intelligent fully biodegradable bag fertilizer provided by the present invention has achieved the following beneficial effects:

[0025] 1) The timed rupture time is long. The timed rupture time of the timed-release coating materials used in the prior art is generally several hours, which cannot meet the long-term nutrient requirements (1-3 months) of crops;

[0026] 2) The time of timed rupture is precisely adjustable and more intelligent. In the process of preparing modified nanoparticles coated with compatible materials, we change the dosage ratio of compatible material A, solvent B and nano-scale water-explosive particles C to prepare modified nanoparticles D with different thicknesses of compatible material coating. Therefore, by accurately controlling the thickness of the coating barrier layer from 1 to 50 nm, the time for water to enter the barrier layer and the controlled release time of nutrients can be precisely controlled within the range of 1 to 3 months;

[0027] 3) The highly water-resistant intelligent fully biodegradable bag-controlled fertilizer prepared by the above method can achieve timed release of fertilizer and adjust its release time by adjusting the thickness of the barrier layer. Fertilizers with different barrier layer thicknesses can be blended and used, and can be released in stages at different growth stages in the plant growth cycle, thereby achieving long-term topdressing at different growth stages of crops;

[0028] 4) Develop fully biodegradable bag-controlled fertilizer using fully biodegradable film materials. The film materials are fully biodegradable in the soil, and the cost of the film materials is reduced by 3-6 times, solving the problem of difficult degradation and high cost of controlled-release fertilizer film materials;

[0029] 5) Water-explosive nanoparticles will produce gases such as acetylene, oxygen, and NH3 when they explode in water, which can promote the growth and development of crops. For example, acetylene can be used as a substitute for growth hormones, inducing plants to produce auxins and gibberellins in the body; oxygen not only directly affects the root respiration and nutrient absorption of plants, but also indirectly affects the activities of soil microorganisms and the physical properties of the soil, thus having a profound impact on the growth and development of plants; NH3 can be dissolved in soil water to provide nutrients for plant growth;

[0030] 6) The processing technology of the present invention is simple, with low energy consumption and high efficiency, and is a low-energy process. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1This is a graph showing the change in water barrier properties of the fully biodegradable bag fertilizer control membrane material in which the water-explosive inorganic nanoparticles modified by coating with compatible materials are added to the membrane material in Examples 1-4 of the present invention, and in which the water-explosive inorganic nanoparticles modified by coating with compatible materials are not added to the membrane material in Comparative Examples 1-1, 2-1, 3-1, and 4-1.

[0032] Figure 2 The schematic diagram is a principle diagram of improving the water vapor barrier capability of the degradable film material by adding water-explosive inorganic nanoparticles coated with compatible materials to the film material of the present invention, and the nutrient controlled-release early nanoparticles of the fully biodegradable bag-controlled fertilizer.

[0033] Figure 3 The schematic diagram is a schematic diagram of the principle of the moisture-sensitive timed explosion of the fully biodegradable bagged fertilizer containing water-explosive inorganic nanoparticles modified by adding compatible materials to the membrane material of the present invention and the intelligent fully biodegradable bagged fertilizer releasing nutrients in the later stage.

[0034] Figure 4 The SEM cross-sectional morphology of the fully biodegradable bag fertilizer control membrane material containing water-explosive inorganic nanoparticles coated and modified by adding a compatible material in the membrane material in Examples 1-4 of the present invention.

[0035] Figure 5 The nutrient release curves of the fully biodegradable bagged fertilizers in Examples 1-4 of the present invention in which the water-explosive inorganic nanoparticles modified by coating with compatible materials are added to the film materials, and in Comparative Examples 1-1, 2-1, 3-1, and 4-1 in which the water-explosive inorganic nanoparticles modified by coating with compatible materials are not added to the film materials.

[0036] Figure 6 This is a degradation rate curve of the fully biodegradable bag fertilizer control film material containing water-explosive inorganic nanoparticles coated and modified by adding a compatible material in the film material in Examples 1-4 of the present invention after being buried in the soil for 180 days.

[0037] Figure 7 This is a SEM surface morphology of the fully biodegradable bag fertilizer control film material containing water-explosive inorganic nanoparticles modified by adding a compatible material to the film material in Examples 1-4 of the present invention after being buried in the soil for 180 days. DETAILED DESCRIPTION

[0038] 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.

[0039] Water vapor barrier performance test: According to GB / T 1037-2021, the water vapor barrier capacity of the degradable film is tested by the cup method. The method is to cut the film into pieces with an area of ​​3.3×10 -3 m 2The circular sample was tested at a temperature of 38°C and a humidity of 90%. The test was preheated for 1 hour and the water vapor transmission rate data was tested. The average value was obtained by performing three parallel tests.

[0040] Film degradation curve detection method: The soil burial method was used to determine the soil degradation rate of the fully biodegradable bag fertilizer control film. The sample film was cut into 5cm*5cm size and buried in the soil at a depth of 8cm. Samples were taken at different sampling times (45th, 90th, 135th, and 180th days), washed 3 times with deionized water, dried in an oven at 60℃, weighed, and the film degradation rate was calculated.

[0041] Refer to the international standard ISO 18644-2016 for controlled-release fertilizers to test the nutrient release curve: add 10g of degradable bag-controlled fertilizer to a 250mL plastic bottle, then add 200mL of deionized water, and culture under static water conditions at 25°C. Determine the nutrient release rate using the refractive index method on the 1st, 3rd, 5th, 7th, 14th, 21st, and 7n (n≥1) days, and take the days when the nutrient release reaches 80% as the nutrient release period of the controlled-release fertilizer. Set up 3 replicates for each test sample.

[0042] Unless otherwise specified, the substances, reagents and materials used in the present invention are all commercially available products.

[0043] Example 1

[0044] A highly water-resistant, intelligent, fully biodegradable PHA bag-sealed controlled-release urea and a preparation method thereof, which is prepared according to the following raw materials and methods in parts by weight:

[0045] (1) Natural rubber (purchased from Guangzhou Housheng New Materials Co., Ltd., BR9000) was dissolved in solvent gasoline, and then nano-scale water-explosive sodium particles were added (nano-scale sodium single substance particles were prepared by melt oscillation method, refer to "Liu Zongming. Collection of Chemical Experiment Operation Experience; Higher Education Press, 1989"). After mechanical stirring and vacuum drying, natural rubber-coated modified nano-sodium particles were obtained, wherein the vacuum drying pressure was 0.01 MPa, the vacuum drying temperature was 30°C, the mechanical stirring rate was 10 r / min, the particle size of the natural rubber-coated modified nano-sodium particles was 1-10 nm, the coating layer thickness was 1-10 nm, and the amount ratio of natural rubber, gasoline and nano-scale water-explosive sodium particles was 0.1 g:100 mL:1 g.

[0046] (2) Natural rubber coated modified nano sodium particles and fully biodegradable resin PHA were blended in a ratio of 0.1 g:100 g for 1 min at a mixing rate of 50 r / min, and then the mixture was granulated by a twin-screw extruder to obtain a composite masterbatch. The feed rate was 50 g / min, the screw speed was 100 rpm, and the temperature from the feed port to the die was set to 80 / 80 / 90 / 90 / 70 / 70 / 60°C. Finally, the composite masterbatch was blown into a film by a single-screw film blowing machine. The die temperature was set to 120 / 130 / 125 / 110 / 100°C to obtain a fully biodegradable PHA controlled release film material with a film thickness of 5 μm.

[0047] (3) The fully biodegradable PHA controlled-release film material prepared above and containing sodium nanoparticles coated with natural rubber was used to heat-seal and encapsulate granular urea to obtain fully biodegradable PHA bag-sealed controlled-release urea. The heat-sealing temperature parameter was 50°C, the mass ratio of the PHA film material to the fully biodegradable PHA bag-sealed controlled-release urea was 0.06g:6g, and the controlled-release time was 36.6 days.

[0048] Application Example 1

[0049] The specific application method of the fully biodegradable PHA bag-sealed controlled-release urea prepared in Example 1 is as follows:

[0050] Using transplanted rice as the test crop, a field application test of fully biodegradable PHA bag-sealed controlled-release urea with natural rubber-coated modified nano-sodium particles prepared in Example 1 was conducted in Linyi City, Shandong Province from June 2023 to October 2023. The average yield of the test field in the first five years was 6.40×10 3 kg / ha; the area of ​​a single test plot is 25m 2 , The following embodiments and comparative examples were tested using three test plots, and the final data were obtained by taking the average value;

[0051] The specific process is: the test fertilizer is spread into the test field as a base fertilizer at one time, and the test fertilizer includes nitrogen fertilizer, phosphorus fertilizer and potash fertilizer, and then the test fertilizer is plowed into the soil at a depth of 8 cm, and then transplanted manually, the spacing between transplanted rice plants is 13.5 cm, the row spacing is 25 cm, and the nitrogen application rate is 300 kg / ha (pure), and the test nitrogen material is: the fully biodegradable PHA bag-sealed controlled-release urea prepared in Example 1, the mass of its pure nitrogen component accounts for 30% (90 kg / ha) of the nitrogen application rate, and the quick-acting urea (purchased from Hualu Hengsheng Chemical Co., Ltd.), the mass of its pure nitrogen component accounts for 70% (210 kg / ha) of the nitrogen application rate. The quick-acting urea in the test fertilizer can provide the nitrogen required for the early growth of transplanted rice; the fully biodegradable PHA bag-sealed 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, with a phosphorus application rate of 150 kg / ha (pure); the potassium fertilizer used was potassium sulfate, with a potassium application rate of 200 kg / ha (pure). The management measures such as rotary tillage, irrigation, pest control, weeding, and harvesting during the growth period of transplanted rice were the same as those of farmers' conventional management measures.

[0052] The seed yield of transplanted rice under this treatment was 8.14×10 3 kg / ha, the total income is: 26862.00 yuan / ha, the net income is: 7711.61 yuan / ha, and the increase in income is 6222.29 yuan / ha (as shown in Table 1);

[0053] The gas produced by the fully biodegradable PHA bag sealed controlled-release urea coated with modified nano-sodium particles by gas chromatography-mass spectrometry in the field is hydrogen. This type of gas has the functions of resisting plant stress, promoting growth and development, improving the root environment of plants, and regulating the effects of plant hormones. The reaction equation is: 2Na+2H2O=2Na + +2OH - +H2↑.

[0054] Comparative Example 1-1

[0055] By weight percentage: fully biodegradable PHA bag sealed controlled release urea (controlled release time is 38.3 days) (the natural rubber coated modified nano sodium particles in Example 1 are not added to the membrane material, and the other preparation steps are the same as in Example 1), the pure nitrogen component mass of which accounts for 30% (90 kg / ha) of the nitrogen application amount, and quick-acting urea (purchased from Hualu Hengsheng Chemical Co., Ltd.), the pure nitrogen component mass of which accounts for 70% (210 kg / ha) of the nitrogen application amount; other factors are consistent with the treatment in Example 1. Transplanted rice seed yield is: 7.60×10 3 kg / ha, the total income is: 25080.00 yuan / ha, the net income is: 6000.35 yuan / ha, and the increase in income is 4511.03 yuan / ha (as shown in Table 1).

[0056] Comparative Example 1-2

[0057] According to the weight percentage, the "blue film" controlled-release urea with a controlled-release period of 60 days produced by Nongda Fertilizer Company, which uses polyurethane as the film material, has a pure nitrogen component mass of 30% (90 kg / ha) of the nitrogen application amount, and the quick-acting urea (purchased from Hualu Hengsheng Chemical Co., Ltd.), has a pure nitrogen component mass of 70% (210 kg / ha) of the nitrogen application amount; other factors are consistent with the treatment in Application Example 1. The seed yield of transplanted rice is: 7.25×10 3 kg / ha, the total income is: 23925.00 yuan / ha, the net income is: 4633.12 yuan / ha, and the increase in income is 3143.80 yuan / ha (as shown in Table 1);

[0058] Comparative Examples 1-3

[0059] According to the weight percentage, quick-acting urea (purchased from Hualu Hengsheng Chemical Co., Ltd.) has a pure nitrogen component mass of 100% (300 kg / ha) of the nitrogen application amount (quick-acting urea is applied as base fertilizer and topdressing. The base fertilizer is applied when transplanting rice seedlings, and the pure nitrogen component mass of the base fertilizer accounts for 70% (210 kg / ha) of the nitrogen application amount. The topdressing is applied twice, 10 days and 1 month after transplanting rice seedlings. The pure nitrogen component mass of each topdressing accounts for 15% (45 kg / ha) of the nitrogen application amount, and the pure nitrogen component mass of the two topdressings accounts for 30% (90 kg / ha) of the nitrogen application amount; phosphorus and potassium fertilizers are applied as base fertilizers at one time); other factors are consistent with the treatment in Application Example 1. The seed yield of transplanted rice is: 6.42×10 3 kg / ha, the total income is: 21186.00 yuan / ha, and the net income is: 1489.32 yuan / ha (as shown in Table 1);

[0060] Compared with Comparative Examples 1-1, 1-2, and 1-3, the rice seed yield treated with the solution in Example 1 was the largest (8.14×10 3 kg / ha), with the largest net income (7711.61 yuan / ha), and an increase of 6222.29 yuan / ha.

[0061] Taking Comparative Examples 1-3 as references, the yield increase rate and income increase were calculated. The calculation formulas for the yield increase rate and income increase are as follows.

[0062] Yield increase rate = [(yield of this example - yield of comparative example 1-3) / (yield of comparative example 1-3)] × 100%

[0063] Increased income = net income of this example - net income of comparative examples 1-3.

[0064] The water barrier properties of the fully biodegradable bag fertilizer film material in which the water-explosive inorganic nanoparticles modified by the compatibility material are added to the film material in Example 1 of the present invention and the water-explosive inorganic nanoparticles modified by the water-explosive inorganic nanoparticles not added to the film material in Comparative Example 1-1 are significantly different, which indicates that in the early stage of nutrient release of this type of fertilizer, the coated nanoparticles in the film material play a role in blocking water entry and nutrient dissolution, achieving a high barrier effect in the early stage ( Figure 1 ).

[0065] The fully biodegradable bag-controlled fertilizer with water-explosive inorganic nanoparticles coated and modified by compatible materials is added to the film material. The principle of the nutrient controlled release of the early nanoparticles to improve the water vapor barrier capacity of the degradable film material is shown as follows Figure 2 As shown; the principle of the intelligent biodegradable bag fertilizer that releases nutrients in the later stage is sensitive to moisture and explodes at a fixed time as shown in the figure Figure 3 As shown. It is precisely because of the water-explosive property that the SEM cross-section of the fully biodegradable bag fertilizer control membrane material of Example 1 of the present invention, which is modified by adding a compatible material to the membrane material and coating the water-explosive inorganic nanoparticles, has a porous and loose morphology, and water and nutrients can quickly pass through ( Figure 4 ). In the comparative example 1-1 of the present invention, the nutrient release of the fully biodegradable bag-controlled fertilizer without the water-explosive inorganic nanoparticles coated and modified by the compatible material in the film material is faster in the early stage and slower in the later stage, while the nutrient release of the water-explosive inorganic nanoparticles coated and modified by the compatible material in the film material in Example 1 is slower in the early stage and faster in the later stage. This is exactly due to the effect of the water-explosive inorganic nanoparticles, which is consistent with the significant change in the water-blocking performance of the film material ( Figure 5 ).

[0066] In Example 1 of the present invention, the biodegradable bag fertilizer control film material containing water-explosive inorganic nanoparticles modified by adding a compatible material to the film material becomes loose and porous due to the explosion of the nanoparticles, and the film material is more easily degraded. After 180 days of burial, the degradation rate of the film material has reached 81.56% ( Figure 6 ), its SEM surface has become uneven, and the membrane is no longer intact, and part of it has been eroded by microorganisms ( Figure 7 ).

[0067] Example 2

[0068] A highly water-resistant, intelligent, fully biodegradable PCL bag-sealed controlled-release urea and a preparation method thereof, which is prepared according to the following raw materials and methods in parts by weight:

[0069] (1) PET is placed in a solvent of butylene oxide, and then nano-scale water-explosive sodium peroxide particles (obtained by grinding in a nitrogen atmosphere by a planetary ball milling method) are added, and PET-coated modified nano-sodium peroxide particles are obtained by mechanical stirring and vacuum drying, wherein the vacuum drying pressure is 0.04 MPa, the vacuum drying temperature is 50° C., the mechanical stirring rate is 200 r / min, the particle size of the PET-coated modified nano-sodium peroxide particles is 300-400 nm, the coating layer thickness is 10-20 nm, and the amount ratio of PET, butylene oxide and nano-scale water-explosive sodium peroxide particles is 0.3 g:200 mL:3 g.

[0070] (2) PET coated modified nano sodium peroxide particles and fully biodegradable resin PCL were blended in a ratio of 1g:140g for 10min at a mixing rate of 200r / min, and then the mixture was granulated by a twin-screw extruder to obtain a composite masterbatch. The feed rate was 100g / min, the screw speed was 300rpm, and the temperature from the feed port to the die was set to: 120 / 120 / 130 / 130 / 110 / 110 / 100°C. Finally, the composite masterbatch was blown into a film by a single-screw film blowing machine. The die temperature was set to: 150 / 160 / 155 / 140 / 130°C to obtain a fully biodegradable PCL controlled release film material with a film thickness of 7μm.

[0071] (3) The fully biodegradable PCL controlled-release film prepared above and containing PET-coated modified sodium peroxide nanoparticles was used to heat-seal and encapsulate powdered urea to obtain fully biodegradable PCL bag-sealed controlled-release urea. The heat-sealing temperature parameter was 100°C, the mass ratio of PCL film to fully biodegradable PCL bag-sealed controlled-release urea was 0.07g:10g, and the controlled-release time was 52.6 days.

[0072] Application Example 2

[0073] The specific application method of the fully biodegradable PCL bag-sealed controlled-release urea prepared in Example 2 is as follows:

[0074] Using transplanted rice as the test crop, a field application test of fully biodegradable PCL bag-sealed controlled-release urea with PET-coated modified nano sodium peroxide particles prepared in Example 2 was conducted in Linyi City, Shandong Province from June 2023 to October 2023. The average yield of the test field in the first five years was 6.40×10 3 kg / ha; the area of ​​a single test plot is 25m 2 , The following embodiments and comparative examples were tested using three test plots, and the final data were obtained by taking the average value;

[0075] The specific process is: the test fertilizer is spread into the test field as a base fertilizer at one time, and the test fertilizer includes nitrogen fertilizer, phosphorus fertilizer and potash fertilizer, and then the test fertilizer is plowed into the soil at a depth of 8 cm, and then transplanted manually, the spacing between transplanted rice plants is 13.5 cm, the row spacing is 25 cm, and the nitrogen application rate is 300 kg / ha (pure), and the test nitrogen material is: the fully biodegradable PCL bag-sealed controlled-release urea prepared in Example 2, the mass of its pure nitrogen component accounts for 30% (90 kg / ha) of the nitrogen application rate, and the quick-acting urea (purchased from Hualu Hengsheng Chemical Co., Ltd.), the mass of its pure nitrogen component accounts for 70% (210 kg / ha) of the nitrogen application rate. The quick-acting urea in the test fertilizer can provide the nitrogen required for the early growth of transplanted rice; the fully biodegradable PCL bag-sealed 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, with a phosphorus application rate of 150 kg / ha (pure); the potassium fertilizer used was potassium sulfate, with a potassium application rate of 200 kg / ha (pure). The management measures such as rotary tillage, irrigation, pest control, weeding, and harvesting during the growth period of transplanted rice were the same as those of farmers' conventional management measures.

[0076] The seed yield of transplanted rice under this treatment was 8.45×10 3 kg / ha, the total income is: 27885.00 yuan / ha, the net income is: 8699.24 yuan / ha, and the increase in income is 7209.92 yuan / ha (as shown in Table 1);

[0077] Gas chromatography-mass spectrometry showed that the fully biodegradable PCL-bag-sealed controlled-release urea coated with modified nano-sodium peroxide particles coated with PET produces oxygen gas after being released in the field. This type of gas not only directly affects the root respiration and nutrient absorption of plants, but also indirectly affects the activity of soil microorganisms and the physical properties of the soil, thereby having a profound impact on the growth and development of plants. The reaction equation is: 2Na2O2+2H2O=4NaOH+O2↑.

[0078] Comparative Example 2-1

[0079] Fully biodegradable PCL bag sealed controlled release urea (controlled release time of 51.0 days) (the PET coated modified nano sodium peroxide particles in Example 2 are not added to the film material, and the other preparation steps are the same as in Example 2), the mass of its pure nitrogen component accounts for 30% (90 kg / ha) of the nitrogen application amount, and the quick-acting urea (purchased from Hualu Hengsheng Chemical Co., Ltd.), the mass of its pure nitrogen component accounts for 70% (210 kg / ha) of the nitrogen application amount; other factors are consistent with the treatment in Example 2. Transplanted rice seed yield is: 7.52×10 3 kg / ha, the total income is: 24816.00 yuan / ha, the net income is: 5700.98 yuan / ha, and the increase in income is 4211.66 yuan / ha (as shown in Table 1);

[0080] Compared with Comparative Examples 2-1, 1-2, and 1-3, the rice seed yield treated with the solution in Example 2 was the largest (8.45×10 3 kg / ha), with the largest net income (8699.24 yuan / ha), and an increase of 7209.92 yuan / ha.

[0081] The increase in production rate and increase in income in this example are calculated according to the formula for increase in production rate and increase in income in Example 1.

[0082] The water barrier properties of the fully biodegradable bag fertilizer film material in which the water-explosive inorganic nanoparticles modified by the coating of the compatible material are added to the film material in Example 2 of the present invention and the water-explosive inorganic nanoparticles modified by the coating of the compatible material are not added to the film material in Comparative Example 2-1 are significantly different, which indicates that in the early stage of nutrient release of this type of fertilizer, the coated nanoparticles in the film material play a role in blocking water entry and nutrient dissolution, achieving a high barrier effect in the early stage ( Figure 1 ).

[0083] The SEM cross section of the fully biodegradable bag fertilizer control membrane material of Example 2 of the present invention, which is modified by adding a compatible material to the membrane material and coating the water-explosive inorganic nanoparticles, has a porous and loose morphology, and water and nutrients can quickly pass through ( Figure 4 ). In the comparative example 2-1 of the present invention, the nutrient release of the fully biodegradable bag-controlled fertilizer without the water-explosive inorganic nanoparticles coated and modified by the compatible material in the film material is faster in the early stage and slower in the later stage, while the nutrient release of the water-explosive inorganic nanoparticles coated and modified by the compatible material in the film material in Example 2 is slower in the early stage and faster in the later stage. This is exactly due to the effect of the water-explosive inorganic nanoparticles, which is consistent with the significant change in the water-blocking performance of the film material ( Figure 5 ).

[0084] In Example 2 of the present invention, the biodegradable bag fertilizer control film material with water-explosive inorganic nanoparticles coated and modified by a compatible material is added to the film material. Since the explosion of the nanoparticles makes the film material loose and porous, the film material is more easily degraded. After 180 days of burial, the degradation rate of the film material has reached 85.10% ( Figure 6 ), its SEM surface has become uneven, and the membrane is no longer intact, and part of it has been eroded by microorganisms ( Figure 7 ).

[0085] Example 3

[0086] A highly water-resistant, intelligent, fully biodegradable PBSA bag sealed with controlled-release saturated ammonia water and a preparation method thereof, which is prepared according to the following raw materials in parts by weight and by the following method:

[0087] (1) PHB is dissolved in solvent cyclohexanone, and then nano-scale water-explosive magnesium nitride particles (obtained by planetary ball milling) are added, and PHB-coated modified nano-magnesium nitride particles are obtained through mechanical stirring and vacuum drying, wherein the vacuum drying pressure is 0.08 MPa, the vacuum drying temperature is 70° C., the mechanical stirring rate is 500 r / min, the particle size of the PHB-coated modified nano-magnesium nitride particles is 600-700 nm, the coating layer thickness is 20-30 nm, and the amount ratio of PHB, cyclohexanone and nano-scale water-explosive magnesium nitride particles is 0.6 g:400 mL:6 g.

[0088] (2) The PHB-coated modified nano-magnesium nitride particles and the fully biodegradable resin PBSA were blended in a ratio of 4g:180g for 15min at a mixing rate of 600r / min, and then the mixture was granulated by a twin-screw extruder to obtain a composite masterbatch. The feed rate was 400g / min, the screw speed was 500rpm, and the temperature from the feed port to the die was set to: 150 / 150 / 160 / 160 / 140 / 140 / 130°C. Finally, the composite masterbatch was blown into a film by a single-screw film blowing machine. The die temperature was set to: 170 / 180 / 175 / 160 / 150°C to obtain a fully biodegradable PBSA controlled-release film material with a film thickness of 8μm.

[0089] (3) The fully biodegradable PBSA controlled-release film material prepared above and containing PHB-coated modified magnesium nitride nanoparticles was used to heat-seal and encapsulate saturated ammonia water to obtain a fully biodegradable PBSA bag-sealed controlled-release saturated ammonia water. The heat-sealing temperature parameter was 150° C. The mass ratio of the PBSA film material to the fully biodegradable PBSA bag-sealed controlled-release saturated ammonia water was 0.8 g:100 g. The controlled-release time was 66.8 days.

[0090] Application Example 3

[0091] The specific application method of the fully biodegradable PBSA bag-sealed controlled-release saturated ammonia prepared in Example 3 is as follows:

[0092] Using transplanted rice as the test crop, a field application test of a fully biodegradable PBSA bag sealed with controlled-release saturated ammonia water with PHB-coated and modified nano-magnesium nitride particles prepared in Example 3 was conducted in Linyi City, Shandong Province from June 2023 to October 2023. The average yield of the test field in the first five years was 6.40×10 3 kg / ha; the area of ​​a single test plot is 25m 2 , The following embodiments and comparative examples were tested using three test plots, and the final data were obtained by taking the average value;

[0093] The specific process is: the test fertilizer is spread into the test field as a base fertilizer at one time, and the test fertilizer includes nitrogen fertilizer, phosphorus fertilizer and potash fertilizer, and then the test fertilizer is plowed into the soil at a depth of 8 cm, and then transplanted manually, the spacing between transplanted rice plants is 13.5 cm, the row spacing is 25 cm, and the nitrogen application rate is 300 kg / ha (pure), and the test nitrogen material is: the fully biodegradable PBSA bag sealed controlled release saturated ammonia water prepared in Example 3, the mass of its pure nitrogen component accounts for 30% (90 kg / ha) of the nitrogen application rate, and the quick-acting urea (purchased from Hualu Hengsheng Chemical Co., Ltd.), the mass of its pure nitrogen component accounts for 70% (210 kg / ha) of the nitrogen application rate. The quick-acting urea in the test fertilizer can provide the nitrogen required for the early growth of transplanted rice: the fully biodegradable PBSA bag sealed controlled release saturated hydrogen water in the test fertilizer can provide the nitrogen required for the late growth of transplanted rice. The phosphate fertilizer used was superphosphate, with a phosphorus application rate of 150 kg / ha (pure); the potassium fertilizer used was potassium sulfate, with a potassium application rate of 200 kg / ha (pure). The management measures such as rotary tillage, irrigation, pest control, weeding, and harvesting during the growth period of transplanted rice were the same as those of farmers' conventional management measures.

[0094] The seed yield of transplanted rice under this treatment was 7.78×10 3 kg / ha, the total income is: 25674.00 yuan / ha, the net income is: 6509.46 yuan / ha, and the increase in income is 5020.14 yuan / ha (as shown in Table 1);

[0095] Gas chromatography-mass spectrometry showed that the fully biodegradable PBSA bag of PHB-coated modified nano-magnesium nitride particles controlled-release saturated ammonia water produced ammonia gas after release in the field. This gas can be dissolved in soil water to provide nutrients for plant growth. The reaction equation is: Mg3N2+6H2O→3Mg(OH)2+2NH3↑.

[0096] Comparative Example 3-1

[0097] Fully biodegradable PBSA bags sealed with controlled release saturated ammonia water (controlled release time of 87.3 days) (the PHB-coated modified nano-magnesium nitride particles in Example 3 are not added to the membrane material, and the remaining preparation steps are the same as in Example 3), the mass of its pure nitrogen component accounts for 30% of the nitrogen application amount (90kg / ha), and quick-acting urea (purchased from Hualu Hengsheng Chemical Co., Ltd.), the mass of its pure nitrogen component accounts for 70% of the nitrogen application amount

[0098] (210kg / ha); other factors were the same as those in Example 3. The rice seed yield was 7.26×10 3 kg / ha, the total income is: 23958.00 yuan / ha, the net income is: 4864.20 yuan / ha, and the increase in income is 3374.88 yuan / ha (as shown in Table 1);

[0099] Compared with Comparative Examples 3-1, 1-2, and 1-3, the rice seed yield treated with the solution in Example 3 was the largest (7.78×10 3 kg / ha), with the largest net income (6509.46 yuan / ha), and an increase of 5020.14 yuan / ha.

[0100] The increase in production rate and increase in income in this example are calculated according to the formula for increase in production rate and increase in income in Example 1.

[0101] The water barrier properties of the fully biodegradable bag-controlled fertilizer film material in Example 3 of the present invention, in which the water-explosive inorganic nanoparticles modified by the compatibility material are added to the film material, and in Comparative Example 3-1, in which the water-explosive inorganic nanoparticles modified by the compatibility material are not added to the film material, are significantly different, which indicates that in the early stage of nutrient release of this type of fertilizer, the coated nanoparticles in the film material play a role in blocking water entry and nutrient dissolution, achieving a high barrier effect in the early stage ( Figure 1 ).

[0102] The SEM cross section of the fully biodegradable bag fertilizer control membrane material of Example 3 of the present invention, which is modified by adding a compatible material to the membrane material and coating the water-explosive inorganic nanoparticles, has a porous and loose morphology, and water and nutrients can quickly pass through ( Figure 4 ). In the comparative example 3-1 of the present invention, the nutrient release of the fully biodegradable bag-controlled fertilizer without the water-explosive inorganic nanoparticles coated and modified by the compatible material in the film material is faster in the early stage and slower in the later stage, while the nutrient release of the water-explosive inorganic nanoparticles coated and modified by the compatible material in the film material in Example 3 is slower in the early stage and faster in the later stage. This is exactly due to the effect of the water-explosive inorganic nanoparticles, which is consistent with the significant change in the water barrier properties of the film material ( Figure 5 ).

[0103] In Example 3 of the present invention, the biodegradable bag fertilizer control film material with water-explosive inorganic nanoparticles coated and modified by a compatible material is added to the film material. Since the explosion of the nanoparticles makes the film material loose and porous, the film material is more easily degraded. After 180 days of burial, the degradation rate of the film material has reached 92.87% ( Figure 6 ), its SEM surface has become uneven, and the membrane is no longer intact, and part of it has been eroded by microorganisms ( Figure 7 ).

[0104] Example 4

[0105] A highly water-resistant, intelligent, fully biodegradable PGA bag sealed controlled-release ammonium bicarbonate and a preparation method thereof, characterized in that it is made from the following raw materials in parts by weight:

[0106] (1) PLLA is dissolved in isopropane solvent, and then nano-scale water-explosive calcium carbide particles (obtained by planetary ball milling) are added, and PLLA-coated modified nano-calcium carbide particles are obtained through mechanical stirring and vacuum drying. The vacuum drying pressure is 0.1 MPa, the vacuum drying temperature is 90° C., the mechanical stirring rate is 1000 r / min, the particle size of the PLLA-coated modified nano-calcium carbide particles is 900-1000 nm, the coating layer thickness is 40-50 nm, and the amount ratio of PLLA, isopropane and nano-scale water-explosive calcium carbide particles is 1 g:500 mL:10 g.

[0107] (2) PLLA-coated modified nano-calcium carbide particles and fully biodegradable resin PGA were blended in a ratio of 8 g:200 g for 20 min at a mixing rate of 1000 r / min, and the mixture was then granulated through a twin-screw extruder to obtain a composite masterbatch. The feed rate was 600 g / min, the screw speed was 800 rpm, and the temperature from the feed port to the die was set to 220 / 220 / 230 / 230 / 210 / 210 / 200°C. Finally, the composite masterbatch was blown into a film through a single-screw film blowing machine. The die temperature was set to 200 / 220 / 210 / 190 / 190°C to obtain a fully biodegradable PGA controlled-release film material with a film thickness of 10 μm.

[0108] (3) The fully biodegradable PGA controlled-release film material prepared above and containing PLLA-coated modified calcium carbide nanoparticles was used to heat-seal and encapsulate powdered ammonium bicarbonate to obtain fully biodegradable PGA bag-sealed controlled-release ammonium bicarbonate. The heat-sealing temperature parameter was 200°C, the mass ratio of the PGA film material to the fully biodegradable PGA bag-sealed controlled-release ammonium bicarbonate was 1g:200g, and the controlled-release time was 87.4 days.

[0109] Application Example 4

[0110] The specific application method of the fully biodegradable PGA bag-sealed controlled-release ammonium bicarbonate prepared in Example 4 is as follows:

[0111] Using transplanted rice as the test crop, a field application test of fully biodegradable PGA bag-sealed controlled-release ammonium bicarbonate with PLLA-coated modified nano-calcium carbide particles prepared in Example 4 was conducted in Linyi City, Shandong Province from June 2023 to October 2023. The average yield of the test field in the first five years was 6.40×10 3 kg / ha; the area of ​​a single test plot is 25m 2 , The following embodiments and comparative examples were tested using three test plots, and the final data were obtained by taking the average value;

[0112] The specific process is: the test fertilizer is spread into the test field as a base fertilizer at one time, and the test fertilizer includes nitrogen fertilizer, phosphorus fertilizer and potash fertilizer, and then the test fertilizer is plowed into the soil at a depth of 8 cm, and then transplanted manually, the spacing between transplanted rice plants is 13.5 cm, the row spacing is 25 cm, and the nitrogen application rate is 300 kg / ha (pure), and the test nitrogen material is: the fully biodegradable PGA bag-sealed controlled-release ammonium bicarbonate prepared in Example 4, the mass of its pure nitrogen component accounts for 30% (90 kg / ha) of the nitrogen application rate, and the quick-acting urea (purchased from Hualu Hengsheng Chemical Co., Ltd.), the mass of its pure nitrogen component accounts for 70% (210 kg / ha) of the nitrogen application rate. The quick-acting urea in the test fertilizer can provide the nitrogen required for the early growth of transplanted rice; the fully biodegradable PGA bag-sealed controlled-release ammonium bicarbonate in the test fertilizer can provide the nitrogen required for the late growth of transplanted rice. The phosphate fertilizer used was superphosphate, with a phosphorus application rate of 150 kg / ha (pure); the potassium fertilizer used was potassium sulfate, with a potassium application rate of 200 kg / ha (pure). The management measures such as rotary tillage, irrigation, pest control, weeding, and harvesting during the growth period of transplanted rice were the same as those of farmers' conventional management measures.

[0113] The seed yield of transplanted rice under this treatment was 7.51×10 3 kg / ha, the total income is: 24783.00 yuan / ha, the net income is: 5653.83 yuan / ha, and the increase in income is 4164.51 yuan / ha (as shown in Table 1);

[0114] Gas chromatography-mass spectrometry showed that the fully biodegradable PGA-bag-sealed controlled-release ammonium bicarbonate of PLLA-coated modified nano-calcium carbide particles produced acetylene as a gas after being released in the field. This type of gas can be used as a substitute for growth hormone and can induce plants to produce auxin and gibberellins in the plant body. The reaction equation is: CaC2+2H2O=Ca(OH)2+C2H2↑.

[0115] Comparative Example 4-1

[0116] Fully biodegradable PGA bag sealed controlled release ammonium bicarbonate (controlled release time is 105.4 days) (PLLA coated modified nano calcium carbide particles are not added to the membrane material, and the other preparation steps are the same as those in Example 4), the mass of its pure nitrogen component accounts for 30% (90 kg / ha) of the nitrogen application amount, and quick-acting urea (purchased from Hualu Hengsheng Chemical Co., Ltd.), the mass of its pure nitrogen component accounts for 70% (210 kg / ha) of the nitrogen application amount; other factors are consistent with the treatment of Example 4. Transplanted rice grain yield is: 7.12×10 3 kg / ha, the total income is: 23496.00 yuan / ha, the net income is: 4437.57 yuan / ha, and the increase in income is 2948.25 yuan / ha (as shown in Table 1);

[0117] Compared with Comparative Examples 4-1, 1-2, and 1-3, the rice seed yield treated with the solution of Example 4 was the largest (7.51×10 3 kg / ha), with the largest net income (5653.83 yuan / ha), and an increase of 4164.51 yuan / ha.

[0118] The increase in production rate and increase in income in this example are calculated according to the formula for increase in production rate and increase in income in Example 1.

[0119] The water barrier properties of the fully biodegradable bag fertilizer film material in Example 4 of the present invention, in which the water-explosive inorganic nanoparticles modified by coating with a compatible material are added, and in Comparative Example 4-1, in which the water-explosive inorganic nanoparticles modified by coating with a compatible material are not added, are significantly different, which indicates that in the early stage of nutrient release of this type of fertilizer, the coated nanoparticles in the film material play a role in blocking water entry and nutrient dissolution, achieving a high barrier effect in the early stage ( Figure 1 ).

[0120] The SEM cross section of the fully biodegradable bag fertilizer control membrane material of Example 4 of the present invention, which is modified by adding a compatible material to the membrane material and coating the water-explosive inorganic nanoparticles, has a porous and loose morphology, and water and nutrients can quickly pass through ( Figure 4 ). In the comparative example 4-1 of the present invention, the nutrient release of the fully biodegradable bag-controlled fertilizer without the water-explosive inorganic nanoparticles coated and modified by the compatible material in the film material is faster in the early stage and slower in the later stage, while the nutrient release of the water-explosive inorganic nanoparticles coated and modified by the compatible material in the film material in Example 4 is slower in the early stage and faster in the later stage. This is exactly due to the effect of the water-explosive inorganic nanoparticles, which is consistent with the significant change in the water-blocking performance of the film material ( Figure 5 ).

[0121] In Example 4 of the present invention, the biodegradable bag fertilizer control film material with water-explosive inorganic nanoparticles coated and modified by a compatible material is added to the film material. Since the explosion of the nanoparticles makes the film material loose and porous, the film material is more easily degraded. After 180 days of burial, the degradation rate of the film material has reached 89.72% ( Figure 6 ), its SEM surface has become uneven, and the membrane is no longer intact, and part of it has been eroded by microorganisms ( Figure 7 ).

[0122] Table 1

[0123]

[0124] Note: The purchase price of rice is 3.3 yuan / kg. Other expenses include: seed cost (80 yuan / mu), transplanting cost (300 yuan / mu), pesticide cost (150 yuan / mu), water cost (100 yuan / mu), mechanical tillage cost (100 yuan / mu), and harvesting cost (80 yuan / mu); labor expenses: base fertilizer and topdressing are both 30 yuan / mu / time, spraying (70 yuan / mu), and field management (90 yuan / mu).

[0125] It can be seen that among the above embodiments, embodiment 2 has the best effect and can be widely promoted and applied.

[0126] 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 highly water-resistant, intelligent, fully biodegradable bag-controlled fertilizer, characterized in that: The following steps are involved: 1) Dissolve the compatible material A in the solvent B, then add the nano-scale water-explosive particles C, and obtain the modified nano-particles D coated with the compatible material through mechanical stirring and vacuum drying; The compatible material A is one or more of natural rubber, PET, PHB, and PLLA; The nanometer-scale water-explosive particles C are one or more of sodium, potassium, barium, rubidium, strontium, cesium, or their hydrides or peroxides, or magnesium nitride and calcium carbide; 2) The modified nanoparticles D coated with the compatible material and the fully biodegradable resin E are blended, and the fully biodegradable controlled release membrane F is prepared through granulation and film blowing processes; 3) The fully biodegradable controlled-release film F is used to heat-seal and encapsulate the fertilizer G to obtain a highly water-resistant intelligent fully biodegradable controlled-release bag fertilizer H.

2. The method for preparing the highly water-resistant intelligent fully biodegradable bag-controlled fertilizer according to claim 1, characterized in that: The solvent B is one or more of gasoline, trichlorobutane, butylene oxide, cyclohexanone and isopropane.

3. The method for preparing the highly water-resistant intelligent fully biodegradable bag-controlled fertilizer according to claim 1, characterized in that: In the step 1), the vacuum drying pressure is 0.01-0.1 MPa, the vacuum drying temperature is 30-90° C., the mechanical stirring rate is 10-1000 r / min, and the usage ratio of the compatible material A, the solvent B and the nano-scale water-explosive particles C is (0.1-1) g: (100-500) mL: (1-10) g.

4. The method for preparing the highly water-resistant intelligent fully biodegradable bag-controlled fertilizer according to claim 1, characterized in that: The particle size of the modified nanoparticle D is 1-1000 nm, and the thickness of the coating layer is 1-50 nm.

5. The method for preparing the highly water-resistant intelligent fully biodegradable bag-controlled fertilizer according to claim 1, characterized in that: The fully biodegradable resin E in step 2) is one or more of PHA, PCL, PBSA and PGA.

6. The method for preparing the highly water-resistant intelligent fully biodegradable bag-controlled fertilizer according to claim 1, characterized in that: The specific preparation process of the fully biodegradable controlled release membrane material F in step 2) is as follows: the modified nanoparticles D and the fully biodegradable resin E are blended in a high-speed mixer at a blending ratio of (0.1-8) g:(100-200) g for 1-20 min at a mixing rate of 50-1000 r / min, and then the mixture is granulated by a twin-screw extruder to obtain a composite masterbatch at a feed rate of 50-600 g / min and a screw speed of 100-800 rpm. The temperature from the feed port to the die is set to (80-220) / (80-220) / (90-230) / (90-230) / (70-210) / (70-210) / (60-200) ℃, and finally the composite masterbatch is blown into film by a single-screw film blowing machine. The head temperature is set to: (120-200) / (130-220) / (125-210) / (110-190) / (100-190)℃, and the film thickness is 5-10μm.

7. The method for preparing the highly water-resistant intelligent fully biodegradable bag-controlled fertilizer according to claim 1, characterized in that: The fertilizer G is one or more of granular fertilizer, powder fertilizer, liquid fertilizer and organic fertilizer.

8. The method for preparing the highly water-resistant intelligent fully biodegradable bag-controlled fertilizer according to claim 1, characterized in that: The heat sealing temperature in step 3) is 50-200° C., and the mass ratio of the fully biodegradable controlled-release membrane material F to the highly water-resistant intelligent fully biodegradable bag controlled fertilizer H is (0.06-1) g:(6-200) g.

9. A highly water-resistant, intelligent, fully biodegradable bag-controlled fertilizer prepared by the preparation method according to any one of claims 1 to 8.

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