Disease and pest inhibition type organic fertilizer based on nano material loading and preparation method thereof

Abstract

The invention provides a plant disease and insect pest inhibition type organic fertilizer based on nanomaterial loading and a preparation method thereof, and belongs to the technical field of fertilizers, the plant disease and insect pest inhibition type organic fertilizer comprises: a nanocellulose whisker carrier derived from agricultural wastes; the plant-derived insect-inhibiting component is loaded on the surface of the carrier through an ester bond and a hydrogen bond; the sodium alginate-lignin porous gel network is used for wrapping the carrier; through double bonding of an agricultural waste nano-cellulose carrier and tea saponin-allicin and in combination with a sodium alginate-lignin gradient gel network, the residual rate of active ingredients in 60 days is larger than 40%, the rhizosphere targeted enrichment concentration reaches 3.28 times of that of a non-rhizosphere region, the problems that a traditional organic fertilizer is short in lasting period and poor in targeting property, and a synthetic carrier is polluted are solved, and the application prospect is wide. While the pest control efficiency and the crop yield are improved, environment friendliness and cost effectiveness are both considered, and a solution with innovativeness and practicability is provided for organic agriculture.

Description

Technical Field

[0001] The present invention belongs to the technical field of fertilizers, especially the pest control type organic fertilizer based on nanomaterial loading and its preparation method. Background Art

[0002] Currently, the pest control type organic fertilizers mainly adopt three technical routes: physical mixing, chemical coating or synthetic nanocarrier loading, but all have significant limitations. Although the physical mixing process is simple, the plant-derived insecticidal components are easily decomposed quickly, with a holding period of less than 15 days and no rhizosphere-directed release. Although the chemical coating type extends the release to 30 - 40 days, its polymer coating is difficult to degrade, leading to soil microplastic pollution and lacking rhizosphere responsiveness, such as polylactic acid. For the nanocarrier loading technology, such as nano-silica, although it can improve stability, due to the ecological toxicity of the synthetic materials and the dependence on pesticide components (such as azadirachtin), it does not meet the organic standards and there is a residue risk.

[0003] In view of the above problems, the present invention provides a pest control type organic fertilizer based on nanomaterial loading and its preparation method. First, nano-crystalline cellulose whiskers extracted from agricultural waste are used to replace synthetic carriers. Second, the tea saponin - allicin complex is loaded through double chemical bonding of ester bonds + hydrogen bonds. The holding period of the insecticidal components is extended to more than 60 days. Finally, an alginate - lignin gel network is constructed, and targeted release is triggered by rhizosphere pectinase, achieving a rhizosphere enrichment concentration of active ingredients 3.28 times that of the non-rhizosphere area, improving the utilization rate while ensuring environmental safety. Summary of the Invention

[0004] The purpose of the present invention is to address the above problems in the existing technology and provide a pest control type organic fertilizer based on nanomaterial loading and its preparation method.

[0005] The purpose of the present invention can be achieved by the following technical solutions: The pest control type organic fertilizer based on nanomaterial loading includes: A nano-crystalline cellulose whisker carrier derived from agricultural waste, and the agricultural waste is selected from wheat straw, rice straw or mulberry bark phloem; Plant-derived insecticidal components loaded on the surface of the carrier through ester bonds and hydrogen bonds, and the plant-derived insecticidal components are a complex of tea saponin and allicin; An alginate - lignin porous gel network wrapping the carrier.

[0006] By loading plant-derived insecticidal components through double chemical bonding of ester bonds and hydrogen bonds to replace physical adsorption, combined with the alginate - lignin gel network, the residual rate of active ingredients > 40% after 60 days and the rhizosphere concentration are increased to 3.28 times that of the non-rhizosphere area are achieved, solving the problems of short holding period and poor targeting of conventional fertilizers.

[0007] Preferably, the nanocellulose whiskers are derived from agricultural waste, including wheat straw, rice straw or mulberry bast, with a diameter of 5-25 nm and a length of 200-400 nm. After TEMPO oxidation, the surface carboxyl content is ≥1.0 mmol / g, providing dense bonding sites, so that the tea saponin loading rate is greater than 85%, and at the same time, the carrier cost is significantly reduced by 62% compared with synthetic nanosilica.

[0008] Preferably, the plant-derived insecticidal ingredient is a complex of tea saponin and allicin, the mass ratio of tea saponin to allicin is (2-4):1, the tea saponin aglycone -OH preferentially forms an ester bond, and the allicin sulfide group -S- is complementary bonded through hydrogen bonds, synergistically improving the aphid contact killing rate and nematode inhibition.

[0009] Preferably, in the sodium alginate-lignin porous gel network, the mass ratio of sodium alginate to sodium lignin sulfonate is (1-2):1, and the lignin sulfonic acid group (-SO3⁻) is used to slow down the Ca²⁺ cross-linking rate, forming a gradient structure of 150-200nm macropores and 50-80nm micropores, so that the gel compressive strength reaches 86.58 MPa (pure sodium alginate ≤40 MPa), and the pectinase diffusion rate is increased by 2.3 times.

[0010] Preferably, the composition comprises, by weight: 3-8 parts of nanocellulose whiskers, 2-5 parts of plant-derived insect repellent ingredients, 5-12 parts of sodium alginate, 4-10 parts of sodium lignin sulfonate, and 500-700 parts of an organic fertilizer base; Among them, 3-8 parts of nanowhiskers balance the load rate and fluidity, 2-5 parts of insect inhibitory ingredients ensure the prevention effect without pesticide damage, and 500-700 parts of organic base fix the gel particles, making the fertilizer's crushing strength ≥15 N, meeting the requirements of mechanical fertilization, and reducing the amount used per hectare by 30%.

[0011] The preparation method of the pest-inhibiting organic fertilizer based on nanomaterial loading comprises the following steps: S1. Support activation: The nanocellulose whiskers were oxidized by TEMPO / NaClO / NaBr system, dialyzed and freeze-dried to obtain carboxylated nanocellulose whiskers with a carboxyl content of ≥1.0 mmol / g; S2. Directed bonding loading: tea saponin and activated carrier are reacted at 50-65°C for 1-3 hours under EDC / NHS catalysis to form an ester bond. Then, an ethanol-water mixture containing allicin (volume ratio 1:4) is added and shaken at 40-50°C for 0.5-1.5 hours to use the polarity of the solvent to induce the thioether group to form a hydrogen bond with the carrier hydroxyl group; S3. In-situ gel encapsulation: Disperse the conjugate obtained in step S2 in a sodium alginate solution, add a premixed solution of sodium lignosulfonate and CaCl₂ (lignin:CaCl₂ = 1:0.3 w / w), and crosslink at 25 - 35 °C for 10 - 30 minutes under stirring to form a porous gel network; S4. Fertilizer granulation: Quick-freeze the gel-encapsulated bodies with liquid nitrogen and then vacuum freeze-dry them, crush them to 100 - 300 μm, and mix them with an organic fertilizer substrate for granulation.

[0012] Preferably, in step S2, the molar ratio of the EDC / NHS catalyst is saponin hydroxyl group:EDC:NHS = 1:(1.2 - 1.5):(0.3 - 0.5), which is used for catalyzing esterification. The pH of the reaction system is controlled at 5.5 - 6.0 by 0.1M MES buffer solution to inhibit the hydrolysis of ester bonds, so that the esterification efficiency > 90% and the by-product < 0.5%.

[0013] Preferably, in step S3, the addition rate of the premixed solution is 5 - 10 mL / min, and the stirring speed is 200 - 500 rpm. The uniform dispersion of lignin is induced by shear force to form a gradient pore size of 50 - 200 nm, reduce the deviation of pore size distribution, and improve the enzymatic hydrolysis response rate.

[0014] Preferably, in step S4, the organic fertilizer substrate is earthworm manure or well-rotted livestock and poultry manure, which is used to provide humic acid to enhance the gel network. The water content during granulation is ≤ 10%. At this time, the granulation rate of the particles ≥ 95%, and low-temperature drying and curing are carried out at 40 - 50 °C to reduce heat loss.

[0015] Preferably, in step S3, the pore size of the formed gel network is 50 - 200 nm, which allows the free diffusion of pectinase but inhibits the burst release of components.

[0016] Compared with the prior art, the pest control and inhibition type organic fertilizer based on nanomaterial loading and its preparation method have the following beneficial effects: 1. The pest control and inhibition type organic fertilizer based on nanomaterial loading and its preparation method provided by the present invention use nanocrystalline cellulose whiskers extracted from agricultural waste, with a 62% reduction in cost compared to synthetic nanosilica carriers, and a saponin loading rate > 85%.

[0017] 2. The pest control and inhibition type organic fertilizer based on nanomaterial loading and its preparation method provided by the present invention use the directional bonding of saponin and allicin to replace physical adsorption, combined with a gel network, to achieve an active ingredient residue rate > 40% after 60 days.

[0018] 3. The pest control and inhibition type organic fertilizer based on nanomaterial loading and its preparation method provided by the present invention use the synergistic effect of saponin and allicin to improve the contact killing rate of aphids and the inhibition of nematodes. Saponin destroys the cell membrane of insects, and allicin interferes with nerve conduction.

[0019] 4. The pest and disease inhibitory organic fertilizer based on nanomaterial loading and its preparation method provided by the present invention. Sodium alginate-lignin forms a gradient pore size, significantly improving the compressive strength compared to adding sodium alginate alone, increasing the diffusion rate of pectinase by 2.3 times, and triggering rhizosphere-targeted release.

[0020] 5. The pest and disease inhibitory organic fertilizer based on nanomaterial loading and its preparation method provided by the present invention. Through the optimization of raw material ratios, the anti-crushing strength of the granules after granulation is ≥15 N, the molding rate is ≥95% when the water content is ≤10%, meeting the requirements of mechanical fertilization and reducing the dosage per hectare by 30%.

[0021] In summary, the present invention provides a pest and disease inhibitory organic fertilizer based on nanomaterial loading and its preparation method. Through the dual bonding of agricultural waste nanocellulose carriers and saponin-allicin, combined with the sodium alginate-lignin gradient gel network, the residual rate of active ingredients after 60 days is >40%, and the rhizosphere-targeted enrichment concentration reaches 3.28 times that of the non-rhizosphere area, overcoming the problems of short effective period, poor targeting, and pollution of synthetic carriers of traditional organic fertilizers. While improving the pest control efficiency and crop yield, it also takes into account environmental friendliness and cost-effectiveness, providing an innovative and practical solution for organic agriculture. Specific embodiments

[0022] The following are specific embodiments of the present invention, further describing the technical solutions of the present invention, but the present invention is not limited to these embodiments. Specific embodiment one

[0024] The pest and disease inhibitory organic fertilizer based on nanomaterial loading, by weight, includes: 3 - 8 parts of nanocellulose whiskers, 2 - 5 parts of plant-derived insecticidal components, 5 - 12 parts of sodium alginate, 4 - 10 parts of sodium lignosulfonate, and 500 - 700 parts of organic fertilizer substrate; The nanocellulose whiskers are derived from agricultural waste, including wheat straw, rice straw, or mulberry bark phloem, with a diameter of 5 - 25 nm and a length of 200 - 400 nm. After TEMPO oxidation, the surface carboxyl content is ≥1.0 mmol / g, providing dense bonding sites, enabling the saponin loading rate to be >85%, and at the same time significantly reducing the carrier cost by 62% compared to synthetic nano-silica; The plant-derived insecticidal components are loaded on the surface of the carrier through ester bonds and hydrogen bonds. The plant-derived insecticidal components are a complex of saponin and allicin, and the mass ratio of saponin to allicin is (2 - 4):1. The saponin aglycone -OH preferentially forms an ester bond, and the allicin thioether group -S- binds through hydrogen bond complementarity, synergistically improving the contact killing rate of aphids and the inhibition of nematodes; The carrier is wrapped by a sodium alginate-lignin porous gel network. In the sodium alginate-lignin porous gel network, the mass ratio of sodium alginate to sodium lignosulfonate is (1-2):1. The lignosulfonic acid group (-SO3⁻) is used to delay the Ca²⁺ cross-linking rate, forming a gradient structure of macropores with a size of 150-200 nm and micropores with a size of 50-80 nm, so that the compressive strength of the gel reaches 86.58 MPa (pure sodium alginate ≤ 40 MPa), and the diffusion rate of pectinase is increased by 2.3 times.

[0025] Load the plant-derived insecticidal components through double chemical bonding of ester bonds and hydrogen bonds, replace physical adsorption, and combine with the sodium alginate-lignin gel network to achieve an active ingredient residue rate > 40% for 60 days and the rhizosphere concentration is increased to 3.3 times that of the non-rhizosphere area, solving the problems of short effective period and poor targeting of conventional fertilizers.

[0026] A preparation method of a pest control type organic fertilizer based on nanomaterial loading, comprising the following steps: S1. Carrier activation: Oxidize nanocrystalline cellulose whiskers through the TEMPO / NaClO / NaBr system, dialyze and then freeze-dry to obtain carboxylated nanocrystalline cellulose whiskers with a carboxyl content ≥ 1.0 mmol / g; S2. Oriented bonding and loading: React tea saponin with the activated carrier under the catalysis of EDC / NHS (the molar ratio of the EDC / NHS catalyst is tea saponin hydroxyl group:EDC:NHS = 1:(1.2-1.5):(0.3-0.5), and the reaction system is controlled at pH 5.5-6.0 by 0.1M MES buffer solution) at 50-65 °C for 1-3 hours to form an ester bond, then add an ethanol-water mixed solution containing allicin (volume ratio 1:4), and oscillate at 40-50 °C for 0.5-1.5 hours to induce the formation of hydrogen bonds between the thioether group and the carrier hydroxyl group by solvent polarity; S3. In-situ gel encapsulation: Disperse the conjugate obtained in step S2 in a sodium alginate solution, add a premixed solution of sodium lignosulfonate and CaCl2 (lignin:CaCl2 = 1:0.3 w / w) (the addition rate of the premixed solution is 5-10 mL / min, the stirring speed is 200-500 rpm, and the uniform dispersion of lignin is induced by shear force to form a gradient pore size of 50-200 nm, reduce the pore size distribution deviation, and improve the enzymatic hydrolysis response rate), and cross-link at 25-35 °C for 10-30 minutes under stirring to form a porous gel network (the pore size of the gel network is 50-200 nm, allowing pectinase to diffuse freely but inhibiting the burst release of components); S4. Fertilizer Pelletizing: The gel inclusions are quickly frozen in liquid nitrogen and then vacuum freeze-dried, crushed to 100 - 300 μm, and mixed and pelletized with an organic fertilizer substrate (the organic fertilizer substrate is earthworm manure or well-rotted livestock and poultry manure, which is used to provide humic acid to enhance the gel network. The water content during pelletizing is ≤ 10%. At this time, the pellet forming rate is ≥ 95%, and it is dried and solidified at a low temperature of 40 - 50 °C to reduce heat loss). Specific Example Two

[0028] The pest and disease inhibitory organic fertilizer based on nanomaterial loading includes the following parts by weight of raw materials: 6 parts of carboxylated nanocellulose whiskers, 2 parts of tea saponin - allicin complex (mass ratio 2:1), 8 parts of low-viscosity sodium alginate, 6 parts of sodium lignosulfonate, and 600 parts of earthworm manure organic substrate.

[0029] Preparation Method: The nanocellulose whiskers extracted from agricultural waste are put into a TEMPO / NaClO / NaBr oxidation system, dialyzed and then freeze-dried to obtain a carboxylated carrier; tea saponin and the activated carrier are reacted at 50 - 65 °C for 1 - 3 hours under the catalysis of EDC / NHS to form an ester bond, and then an ethanol - water mixed solution containing allicin (volume ratio 1:4) is added, and it is oscillated at 40 - 50 °C for 0.5 - 1.5 hours to induce the formation of hydrogen bonds between the thioether group and the carrier hydroxyl group by the solvent polarity; the obtained bonded body is dispersed in a sodium alginate solution, and a premixed solution of sodium lignosulfonate and CaCl2 (lignin:CaCl2 = 1:0.3 w / w) is added, and crosslinked at 25 - 35 °C for 10 - 30 minutes under stirring to form a porous gel network; the gel inclusions are quickly frozen in liquid nitrogen and then vacuum freeze-dried, crushed to 100 - 300 μm, and mixed and pelletized with the organic fertilizer substrate. Specific Example Three

[0031] The pest and disease inhibitory organic fertilizer based on nanomaterial loading includes the following parts by weight of raw materials: 6 parts of carboxylated nanocellulose whiskers, 3.5 parts of tea saponin - allicin complex (mass ratio 2:1), 8 parts of low-viscosity sodium alginate, 6 parts of sodium lignosulfonate, and 600 parts of earthworm manure organic substrate.

[0032] Preparation method: Put the nanocellulose whiskers extracted from agricultural waste into the TEMPO / NaClO / NaBr oxidation system, dialyze and then freeze-dry to obtain a carboxylated carrier; React tea saponin with the activated carrier at 50 - 65 °C for 1 - 3 hours under the catalysis of EDC / NHS to form an ester bond, then add an ethanol-water mixed solution containing allicin (volume ratio 1:4), and oscillate at 40 - 50 °C for 0.5 - 1.5 hours to induce the formation of hydrogen bonds between the thioether group and the carrier hydroxyl group by solvent polarity; Disperse the obtained conjugate in a sodium alginate solution, add a premixed solution of sodium lignosulfonate and CaCl2 (lignin:CaCl2 = 1:0.3 w / w), crosslink at 25 - 35 °C for 10 - 30 minutes under stirring to form a porous gel network; Quick-freeze the gel inclusion body with liquid nitrogen and then vacuum freeze-dry, crush to 100 - 300 μm, and mix and granulate with the organic fertilizer substrate. Specific Example Four

[0034] The pest and disease inhibitory organic fertilizer based on nanomaterial loading comprises the following parts by weight of raw materials: 6 parts of carboxylated nanocellulose whiskers, 5 parts of tea saponin-allicin complex (mass ratio 2:1), 8 parts of low-viscosity sodium alginate, 6 parts of sodium lignosulfonate, and 600 parts of earthworm manure organic substrate.

[0035] Preparation method: Put the nanocellulose whiskers extracted from agricultural waste into the TEMPO / NaClO / NaBr oxidation system, dialyze and then freeze-dry to obtain a carboxylated carrier; React tea saponin with the activated carrier at 50 - 65 °C for 1 - 3 hours under the catalysis of EDC / NHS to form an ester bond, then add an ethanol-water mixed solution containing allicin (volume ratio 1:4), and oscillate at 40 - 50 °C for 0.5 - 1.5 hours to induce the formation of hydrogen bonds between the thioether group and the carrier hydroxyl group by solvent polarity; Disperse the obtained conjugate in a sodium alginate solution, add a premixed solution of sodium lignosulfonate and CaCl2 (lignin:CaCl2 = 1:0.3 w / w), crosslink at 25 - 35 °C for 10 - 30 minutes under stirring to form a porous gel network; Quick-freeze the gel inclusion body with liquid nitrogen and then vacuum freeze-dry, crush to 100 - 300 μm, and mix and granulate with the organic fertilizer substrate. Specific Example Five

[0037] The pest and disease inhibitory organic fertilizer based on nanomaterial loading comprises the following parts by weight of raw materials: 6 parts of carboxylated nanocellulose whiskers, 2 parts of tea saponin-allicin complex (mass ratio 3:1), 8 parts of low-viscosity sodium alginate, 6 parts of sodium lignosulfonate, and 600 parts of earthworm manure organic substrate.

[0038] Preparation method: Put the nanocellulose whiskers extracted from agricultural waste into the TEMPO / NaClO / NaBr oxidation system, dialyze and then freeze-dry to obtain a carboxylated carrier; React tea saponin with the activated carrier at 50 - 65 °C for 1 - 3 hours under the catalysis of EDC / NHS to form an ester bond, then add an ethanol-water mixed solution (volume ratio 1:4) containing allicin, and oscillate at 40 - 50 °C for 0.5 - 1.5 hours to induce the formation of hydrogen bonds between the thioether group and the carrier hydroxyl group by the solvent polarity; Disperse the obtained conjugate in a sodium alginate solution, add a premixed solution of sodium lignosulfonate and CaCl2 (lignin:CaCl2 = 1:0.3 w / w), crosslink at 25 - 35 °C for 10 - 30 minutes under stirring to form a porous gel network; Quick-freeze the gel inclusion body with liquid nitrogen and then vacuum freeze-dry, crush to 100 - 300 μm, and mix and granulate with the organic fertilizer substrate. Specific Example Six

[0040] The pest and disease inhibitory organic fertilizer based on nanomaterial loading comprises the following parts by weight of raw materials: 6 parts of carboxylated nanocellulose whiskers, 3.5 parts of tea saponin-allicin complex (mass ratio 3:1), 8 parts of low-viscosity sodium alginate, 6 parts of sodium lignosulfonate, and 600 parts of earthworm manure organic substrate.

[0041] Preparation method: Put the nanocellulose whiskers extracted from agricultural waste into the TEMPO / NaClO / NaBr oxidation system, dialyze and then freeze-dry to obtain a carboxylated carrier; React tea saponin with the activated carrier at 50 - 65 °C for 1 - 3 hours under the catalysis of EDC / NHS to form an ester bond, then add an ethanol-water mixed solution (volume ratio 1:4) containing allicin, and oscillate at 40 - 50 °C for 0.5 - 1.5 hours to induce the formation of hydrogen bonds between the thioether group and the carrier hydroxyl group by the solvent polarity; Disperse the obtained conjugate in a sodium alginate solution, add a premixed solution of sodium lignosulfonate and CaCl2 (lignin:CaCl2 = 1:0.3 w / w), crosslink at 25 - 35 °C for 10 - 30 minutes under stirring to form a porous gel network; Quick-freeze the gel inclusion body with liquid nitrogen and then vacuum freeze-dry, crush to 100 - 300 μm, and mix and granulate with the organic fertilizer substrate. Specific Example Seven

[0043] The pest and disease inhibitory organic fertilizer based on nanomaterial loading comprises the following parts by weight of raw materials: 6 parts of carboxylated nanocellulose whiskers, 5 parts of tea saponin-allicin complex (mass ratio 3:1), 8 parts of low-viscosity sodium alginate, 6 parts of sodium lignosulfonate, and 600 parts of earthworm manure organic substrate.

[0044] Preparation method: Put the nanocellulose whiskers extracted from agricultural waste into the TEMPO / NaClO / NaBr oxidation system, dialyze and then freeze-dry to obtain a carboxylated carrier; React tea saponin with the activated carrier at 50 - 65 °C for 1 - 3 hours under the catalysis of EDC / NHS to form an ester bond, then add a garlicin-containing ethanol-water mixture (volume ratio 1:4), and oscillate at 40 - 50 °C for 0.5 - 1.5 hours to induce the formation of hydrogen bonds between the thioether group and the carrier hydroxyl group by the solvent polarity; Disperse the obtained conjugate in a sodium alginate solution, add a premixed solution of sodium lignosulfonate and CaCl2 (lignin:CaCl2 = 1:0.3 w / w), crosslink at 25 - 35 °C for 10 - 30 minutes under stirring to form a porous gel network; Quick-freeze the gel inclusion body with liquid nitrogen and then vacuum freeze-dry, crush it to 100 - 300 μm, and mix it with the organic fertilizer substrate for granulation. Specific Example VIII

[0046] The pest and disease inhibition type organic fertilizer based on nanomaterial loading comprises the following parts by weight of raw materials: 6 parts of carboxylated nanocellulose whiskers, 2 parts of tea saponin - garlicin complex (mass ratio 4:1), 8 parts of low-viscosity sodium alginate, 6 parts of sodium lignosulfonate, and 600 parts of vermicompost organic substrate.

[0047] Preparation method: Put the nanocellulose whiskers extracted from agricultural waste into the TEMPO / NaClO / NaBr oxidation system, dialyze and then freeze-dry to obtain a carboxylated carrier; React tea saponin with the activated carrier at 50 - 65 °C for 1 - 3 hours under the catalysis of EDC / NHS to form an ester bond, then add a garlicin-containing ethanol-water mixture (volume ratio 1:4), and oscillate at 40 - 50 °C for 0.5 - 1.5 hours to induce the formation of hydrogen bonds between the thioether group and the carrier hydroxyl group by the solvent polarity; Disperse the obtained conjugate in a sodium alginate solution, add a premixed solution of sodium lignosulfonate and CaCl2 (lignin:CaCl2 = 1:0.3 w / w), crosslink at 25 - 35 °C for 10 - 30 minutes under stirring to form a porous gel network; Quick-freeze the gel inclusion body with liquid nitrogen and then vacuum freeze-dry, crush it to 100 - 300 μm, and mix it with the organic fertilizer substrate for granulation. Specific Example IX

[0049] The pest and disease inhibition type organic fertilizer based on nanomaterial loading comprises the following parts by weight of raw materials: 6 parts of carboxylated nanocellulose whiskers, 3.5 parts of tea saponin - garlicin complex (mass ratio 4:1), 8 parts of low-viscosity sodium alginate, 6 parts of sodium lignosulfonate, and 600 parts of vermicompost organic substrate.

[0050] Preparation method: Put the nanocellulose whiskers extracted from agricultural waste into the TEMPO / NaClO / NaBr oxidation system, dialyze and then freeze-dry to obtain a carboxylated carrier; React tea saponin with the activated carrier at 50 - 65 °C for 1 - 3 hours under the catalysis of EDC / NHS to form an ester bond, then add an ethanol-water mixed solution containing allicin (volume ratio 1:4), and oscillate at 40 - 50 °C for 0.5 - 1.5 hours to induce the formation of hydrogen bonds between the thioether group and the carrier hydroxyl group by the solvent polarity; Disperse the obtained conjugate in a sodium alginate solution, add a premixed solution of sodium lignosulfonate and CaCl₂ (lignin:CaCl₂ = 1:0.3 w / w), crosslink at 25 - 35 °C for 10 - 30 minutes under stirring to form a porous gel network; Quick-freeze the gel inclusion body with liquid nitrogen and then vacuum freeze-dry, crush to 100 - 300 μm, and mix and granulate with the organic fertilizer substrate. Specific Example Ten

[0052] The pest-inhibiting organic fertilizer based on nanomaterial loading comprises the following raw materials in parts: 6 parts of carboxylated nanocellulose whiskers, 5 parts of tea saponin-allicin complex (mass ratio 4:1), 8 parts of low-viscosity sodium alginate, 6 parts of sodium lignosulfonate, and 600 parts of earthworm manure organic substrate.

[0053] Preparation method: Put the nanocellulose whiskers extracted from agricultural waste into the TEMPO / NaClO / NaBr oxidation system, dialyze and then freeze-dry to obtain a carboxylated carrier; React tea saponin with the activated carrier at 50 - 65 °C for 1 - 3 hours under the catalysis of EDC / NHS to form an ester bond, then add an ethanol-water mixed solution containing allicin (volume ratio 1:4), and oscillate at 40 - 50 °C for 0.5 - 1.5 hours to induce the formation of hydrogen bonds between the thioether group and the carrier hydroxyl group by the solvent polarity; Disperse the obtained conjugate in a sodium alginate solution, add a premixed solution of sodium lignosulfonate and CaCl₂ (lignin:CaCl₂ = 1:0.3 w / w), crosslink at 25 - 35 °C for 10 - 30 minutes under stirring to form a porous gel network; Quick-freeze the gel inclusion body with liquid nitrogen and then vacuum freeze-dry, crush to 100 - 300 μm, and mix and granulate with the organic fertilizer substrate.

[0054] Comparative Example One: Do not add the plant-derived insect-inhibiting component, that is, the tea saponin-allicin complex, and the addition amounts of the remaining raw materials and the preparation method are the same as those in Specific Examples Two to Specific Example Ten.

[0055] The physical properties, slow-release performance, insecticidal effect, biocompatibility, and field effect (tomato cultivation) of the fertilizers mentioned in Specific Examples 2 to 10 were tested. The physical properties included particle strength, disintegration time, and water retention; the slow-release performance was tested for the cumulative release rate over 28 days; the insecticidal effect included indoor toxicity and pot experiments; the biocompatibility included seed germination rate and root length inhibition rate, and the field effect (tomato cultivation) included yield increase and disease incidence rate. The methods are as follows.

[0056] Particle strength (N): Referring to GB / T 8574-2010 "Determination of the Crushing Resistance of Compound Fertilizers", 50 fertilizer particles (2-3 mm in diameter) were randomly selected, and the radial compressive strength was measured using a universal material testing machine. Parameters: The downward pressure speed was 1 mm / min, and the maximum force value (N) at the moment of particle rupture was recorded, and the average value ± SD was taken.

[0057] Disintegration time (min): Referring to ISO 18647:2016 "Determination of the Disintegration Characteristics of Controlled-Release Fertilizers", 5 g of fertilizer particles were placed in a 500 mL beaker, and 25°C simulated soil solution (0.01 M CaCl2 + 0.1% humic acid, pH = 6.5) was added, and magnetic stirring was carried out at 100 rpm. The time when the particles were completely dispersed into <0.5 mm fragments was determined by visual inspection combined with sieving.

[0058] Water retention (%) : Referring to ISO11520-2:2001 "Determination of the Water Absorbing Capacity of Agricultural Water Retaining Agents", 10 g of fertilizer with a dry weight of W0 was weighed, immersed in deionized water for 30 min, drained through a filter for 10 min and then weighed as W1; then centrifuged (3000 rpm, 10 min) and weighed as W2. Calculate according to the following formula: Saturated water absorption rate = [(W1 - W0) / W0] × 100% Water retention rate = [(W2 - W0) / W0] × 100% The cumulative release rate over 28 days (%) was measured using an Agilent 1260 HPLC with a C18 chromatographic column (4.6×250 mm, 5 μm). 1.0 g of fertilizer was encapsulated in a dialysis bag (MWCO 8-10 kDa), immersed in 200 mL of release medium (pH = 6.8 phosphate buffer + 0.1% Tween 80), and incubated at 37°C with constant shaking (100 rpm) for simulated release. 5 mL of the release solution (while replenishing the liquid) was taken at 1 h, 6 h, 12 h, 1 d, 3 d, 7 d, 14 d, 21 d, and 28 d, and the concentrations of saponin (λ = 280 nm) and allicin (λ = 220 nm) were measured by HPLC. The cumulative release rate = (total release amount at each time point / total drug loading amount) × 100%.

[0059] Indoor toxicity (LC 50, μg / mL): Referring to FAO Standard No. 225 "Guidelines for Pesticide Bioassay Tests", prepare a gradient of liquid medicine (0, 10, 20, 40, 80, 160 μg / mL). Add 1 mL of liquid medicine and 100 J2 larvae to each petri dish. Incubate in the dark at 25°C for 24 h, and count the dead larvae (no response to the probe) under a microscope. Calculate LC 50 (SPSS Probit analysis). The test insects are second-stage larvae (J2) of root-knot nematodes.

[0060] Pot experiment - Egg reduction rate (%): Inoculate 500 nematode eggs to the roots of tomatoes. After 30 days of fertilization treatment, collect the roots, and separate and count the egg grains by the NaOCl oscillation method. Egg reduction rate = [(egg quantity in the control group - egg quantity in the treatment group) / egg quantity in the control group] × 100%. Grading standard: Grade 0 (no root knots), Grade 1 (1 - 10% of the roots nodulated), Grade 2 (11 - 30%), Grade 3 (31 - 50%), Grade 4 (51 - 80%), Grade 5 (>80%). Use the double-blind method and take the average score independently by 3 people.

[0061] Seed germination rate (%): Lay filter paper in a petri dish, add 5 mL of 1% fertilizer extract (fertilizer: water = 1:10 w / v, extracted for 24 h), and place 20 tomato seeds. Incubate in a light incubator at 25°C for 7 days, and count the number of germinated seeds (radicle ≥ 2 mm). Control: Treated with deionized water.

[0062] Root length inhibition rate (%): Measure the root lengths of 10 seedlings in the above germination test. Root length inhibition rate = [(average root length in the control group - average root length in the treatment group) / average root length in the control group] × 100%.

[0063] Field effect detection (tomato planting) - Yield increase (%): Randomized block design, with 3 replicates in each group (20 plants in each plot), and conventional management. Record the total weight of fruits per plant at maturity, and yield increase = [(yield in the treatment group - yield in the control group) / yield in the control group] × 100%.

[0064] Disease incidence (%): Randomly dig out 10 plants in each plot and record the number of diseased plants (root knot or lesion area > 5%). Disease incidence = (number of diseased plants / total number of surveyed plants) × 100%. Monitoring objects: Root-knot nematode disease, early blight.

[0065] Table 1 Physical and slow-release properties Example Particle Strength (N) Disintegration Time (min) Water Retention Capacity (%) Release Rate at 28 Days (%) Comparative Example 1 18.2±1.3 45±3 320±15 - Specific Example 2 20.1±0.9 52±4 335±12 78.2±2.1 Specific Example 3 21.7±1.2 55±4 350±14 70.1±1.9 Specific Example 4 23.8±1.3 62±4 375±16 62.7±2.4 Specific Example 5 21.9±0.5 53±2 356±10 64.5±1.8 Specific Example 6 22.5±1.4 58±3 360±18 65.3±2.5 Specific Example 7 23.3±0.9 60±2 372±11 72.3±1.8 Specific Example 8 19.8±1.1 50±2 330±10 82.5±1.8 Specific Example 9 22.4±0.8 58±3 363±12 63.0±1.6 Specific Example 10 24.3±1.6 65±5 385±20 58.4±3.0 With the optimization of the addition amount and ratio of the tea saponin-allicin complex, the physical properties of the fertilizer change accordingly. In Example 10 with the highest addition amount, the particle strength increases by 33% and the water retention increases by 20%. This is because the gradient gel network formed by the regulation of sodium lignosulfonate increases the crosslinking density. In terms of the slow-release performance, in the groups with a high proportion of tea saponin (Examples 8, 9, and 10), due to the increase in hydrophilic groups, the 28-day release rate is as low as 58.4%. Combining with the dual-bonding mechanism of ester bond-hydrogen bond, the long-term controlled release of active ingredients is achieved (the 60-day residue rate > 40%).

[0066] Table 2 Insecticidal effect (root-knot nematode) Example <![CDATA[LC 50 (μg / mL)]]> Egg Reduction Rate (%) Root-knot Index (grade) Comparative Example 1 - 8.2±1.5 4.2±0.3 Specific Example 2 35.6±2.1 52.3±3.8 2.8±0.2 Specific Example 3 26.3±1.6 68.2±4.7 1.9±0.3 Specific Example 4 24.5±1.4 79.4±5.8 1.4±0.2 Specific Example 5 23.9±1.5 63.8±2.9 2.5±0.2 Specific Example 6 22.7±1.5 74.5±5.1 1.6±0.2 Specific Example 7 22.3±0.9 82.4±2.7 1.2±0.1 Specific Example 8 28.4±1.8 61.7±4.2 2.3±0.3 Specific Example 9 23.5±0.8 78.9±3.6 1.3±0.2 Specific Example 10 18.9±1.2 86.3±6.3 1.1±0.1 In terms of the core insecticidal effect, the LC of Example 10 against root-knot nematode 50 decreases to 18.9 μg / mL, the egg reduction rate reaches 86.3%, and the root-knot index is only 1.1 level, which is 63% higher than that of Example 2 with the lowest addition amount, highlighting the synergistic effect of tea saponin destroying cell membranes and allicin interfering with nerve conduction.

[0067] Table 3 Biocompatibility and field effect Example Seed Germination Rate (%) Root Length Inhibition Rate (%) Tomato Yield Increase Rate (%) Disease Incidence Rate (%) Comparative Example 1 96.5±2.1 0 0 22.5±3.1 Specific Example 2 94.3±1.8 5.2±0.9 14.3±1.7 15.8±2.4 Specific Example 3 91.8±1.9 9.7±1.1 20.1±2.3 11.2±1.7 Specific Example 4 87.4±1.7 15.4±1.8 26.8±2.9 7.8±1.4 Specific Example 5 91.3±1.5 10.6±0.9 22.6±1.0 14.5±1.8 Specific Example 6 90.5±1.6 11.3±1.5 23.7±2.8 9.6±1.5 Specific Example 7 86.3±1.2 12.1±1.2 25.2±1.1 9.3±1.6 Specific Example 8 92.7±2.0 8.1±1.2 16.2±2.1 13.4±1.9 Specific Example 9 87.4±0.9 11.8±1.3 25.4±2.1 10.3±1.6 Specific Example 10 85.2±2.3 18.6±2.0 29.5±3.2 6.3±1.2 In field applications, although there is a certain phytotoxicity in the high drug-loading groups, such as the root length inhibition rate of Example 10 is 18.6%, it triggers targeted release through rhizosphere pectinase, reducing the disease incidence rate to 6.3%. At the same time, the humic acid provided by the earthworm manure substrate effectively alleviates stress, ultimately achieving a 29.5% increase in tomato yield; while Example 6 in the medium-dose balance group achieves the best balance among insect control, yield increase, and biological safety. In summary, compared with the comparative example without adding plant-derived insecticidal components, all examples show an overall improvement in comprehensive performance. Specific Example 11: Take 1.0 g of the fertilizer particles of Example 10, encapsulate them in a dialysis bag (MWCO 8-10 kDa), simulate the rhizosphere environment, add 0.1 U / mL pectinase (derived from tomato root exudates) to the rhizosphere group, and no enzyme is added to the non-rhizosphere group (pH = 6.8 phosphate buffer + 0.1% Tween 80). Oscillate at a constant temperature of 37°C (100 rpm) for 60 days, sample on the 7th, 14th, 30th, 45th, and 60th days, and detect the residual amounts of tea saponin / allicin by HPLC. The final 60-day residue rate reaches 41.2%. Specific Example 11: Tomato seedlings were planted in a rhizobox, divided into the rhizosphere (0 - 2 mm of soil near the roots) and the non-rhizosphere (>5 mm). The fertilizer of Example 10 was applied to the rhizosphere (1.0 g / kg soil). On the 30th day, the soil in the rhizosphere and non-rhizosphere was collected, quickly frozen in liquid nitrogen and then freeze-dried. It was extracted by ultrasonic with methanol-water (7:3 v / v), and the concentrations of tea saponin / allicin were detected by HPLC-MS / MS. Enrichment factor = concentration of the agent in the rhizosphere / concentration of the agent in the non-rhizosphere. Finally, the enzyme-responsive gel achieved rhizosphere-specific release, and the enrichment factor reached 3.28 times.

[0070] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar ways to substitute, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. The pest and disease inhibitory organic fertilizer based on nanomaterial loading is characterized in that, Comprising: A nanocellulose whisker carrier derived from agricultural waste, wherein the agricultural waste is selected from wheat straw, rice straw or mulberry bark phloem; A plant-derived insecticidal component loaded on the surface of the carrier through ester bonds and hydrogen bonds, and the plant-derived insecticidal component is a complex of tea saponin and allicin; A sodium alginate-lignin porous gel network wrapping the carrier.

2. The pest and disease inhibition type organic fertilizer based on nanomaterial loading according to claim 1, wherein The nanocellulose whiskers have a diameter of 5-25 nm, a length of 200-400 nm, and a surface carboxyl content of ≥1.0 mmol / g.

3. The pest and disease inhibitory organic fertilizer based on nanomaterial loading according to claim 1, characterized in that, The mass ratio of tea saponin to allicin is (2-4):

1.

4. The pest and disease inhibitory organic fertilizer based on nanomaterial loading according to claim 1, characterized in that, In the sodium alginate-lignin porous gel network, the mass ratio of sodium alginate to sodium lignosulfonate is (1-2):

1.

5. The pest and disease inhibition type organic fertilizer based on nanomaterial loading according to claim 1, characterized in that, By weight, it comprises: 3-8 parts of nanocellulose whiskers, 2-5 parts of plant-derived insecticidal component, 5-12 parts of sodium alginate, 4-10 parts of sodium lignosulfonate, and 500-700 parts of organic fertilizer substrate.

6. A preparation method of a pest and disease inhibition type organic fertilizer based on nanomaterial loading, characterized in that, Including the following steps: S1. Carrier activation: Oxidize the nanocellulose whiskers through the TEMPO / NaClO / NaBr system, dialyze and then freeze-dry to obtain carboxylated nanocellulose whiskers with a carboxyl content of ≥1.0 mmol / g; S2. Directed bonding and loading: React tea saponin with the activated carrier at 50-65°C for 1-3 hours under the catalysis of EDC / NHS to form an ester bond, then add an ethanol-water mixed solution containing allicin (volume ratio 1:4), and oscillate at 40-50°C for 0.5-1.5 hours to induce the formation of hydrogen bonds between the thioether group and the carrier hydroxyl group by the solvent polarity; S3. In-situ gel wrapping: Disperse the conjugate obtained in step S2 in a sodium alginate solution, add a premixed solution of sodium lignosulfonate and CaCl2 (lignin:CaCl2 = 1:0.3 w / w), and crosslink at 25-35°C for 10-30 minutes under stirring to form a porous gel network; S4. Fertilizer forming: Quick-freeze the gel-wrapped body with liquid nitrogen and then vacuum freeze-dry, crush it to 100-300 μm, and mix it with the organic fertilizer substrate for granulation.

7. The preparation method of the pest and disease inhibition type organic fertilizer based on nanomaterial loading according to claim 6, characterized in that, In step S2, the molar ratio of the EDC / NHS catalyst is tea saponin hydroxyl group:EDC:NHS = 1:(1.2-1.5):(0.3-0.5), and the pH of the reaction system is controlled at 5.5-6.0 by 0.1M MES buffer solution.

8. The preparation method of the pest and disease inhibition type organic fertilizer based on nanomaterial loading according to claim 6, characterized in that, In step S3, the addition rate of the premixed solution is 5-10 mL / min, and the stirring speed is 200-500 rpm.

9. The preparation method of the pest and disease inhibition type organic fertilizer based on nanomaterial loading according to claim 6, characterized in that, In step S4, the organic fertilizer substrate is earthworm manure or well-rotted livestock and poultry manure. When granulating, the water content is ≤10%, and it is dried and solidified at 40-50°C at low temperature.

10. The preparation method of the pest and disease inhibition type organic fertilizer based on nanomaterial loading according to claim 6, characterized in that, In step S3, the pore size of the formed gel network is 50-200 nm.