Composition for improving lodging resistance of rice and preparation method thereof

Abstract

The invention relates to a composition for improving lodging resistance of rice and a preparation method thereof, and belongs to the technical field of crop planting, the composition specifically comprises the following raw materials in parts by mass: 1.3-2 parts of paclobutrazol, 0.2-0.3 part of gibberellin, 0.1-0.3 part of growth-promoting rhizobacteria, 1-5 parts of modified charcoal and 100 parts of an acrylate-based slow-release material; wherein the modified biochar is prepared by carrying out hydrophobic modification on biochar by using a silane coupling agent. By compounding paclobutrazol, gibberellin, growth-promoting rhizobacteria and modified charcoal, the lodging resistance of rice is improved. Paclobutrazol regulates and controls growth, rhizosphere bacteria promote root health, and modified charcoal improves the soil environment. The composite strain enhances the soil nutrient circulation, and the slow-release material stably releases nutrients and promotes the stalk strength. The whole scheme has a synergistic effect, and the growth stability and lodging resistance of rice are enhanced.

Description

Technical Field

[0001] The present application relates to the technical field of crop planting, and more specifically, to a composition for improving the lodging resistance of rice and a preparation method thereof. Background Art

[0002] In the agricultural field, rice is one of the world's major food crops, and the steady improvement of its yield and quality is crucial to ensuring global food security. However, during its growth, rice is often affected by natural disasters such as wind damage and rainstorms, which cause the plants to fall over, seriously affecting its yield and quality. Traditionally, farmers have relied on chemical fertilizers and pesticides to enhance the stress resistance of rice, but these methods are often accompanied by environmental pollution and the destruction of ecological balance.

[0003] In recent years, with the rapid development of biotechnology and materials science, scientists have begun to explore more environmentally friendly and efficient strategies to improve the lodging resistance of rice. Among them, preparing a composition with specific functions by compounding multiple bioactive substances and modified materials has become a research hotspot. Based on the above statement, the present application provides a composition for improving the lodging resistance of rice and a preparation method thereof. Summary of the invention

[0004] In order to solve the problems raised in the background technology, the present application provides a composition for improving the lodging resistance of rice and a preparation method thereof. The present invention improves the lodging resistance of rice by compounding paclobutrazol, gibberellins, rhizosphere growth-promoting bacteria and modified biochar. Paclobutrazol regulates growth, rhizosphere bacteria promote root health, and modified biochar improves the soil environment. The composite bacteria enhance the soil nutrient cycle, and the slow-release material stably releases nutrients and promotes the strength of the stems. The overall solution works synergistically to enhance the growth stability and lodging resistance of rice.

[0005] The present application provides a composition for improving rice lodging resistance and a preparation method thereof, which adopts the following technical scheme: A composition for improving the lodging resistance of rice, comprising the following raw materials in parts by weight: 1.3-2 parts of paclobutrazol, 0.2-0.3 parts of gibberellins, 0.1-0.3 parts of rhizosphere growth-promoting bacteria, 1-5 parts of modified biochar and 100 parts of acrylate-based slow-release materials; Wherein, the modified biochar is obtained by hydrophobically modifying the biochar with a silane coupling agent.

[0006] Furthermore, the rhizosphere growth-promoting bacteria are obtained by mixing nitrogen-fixing bacteria, Pseudomonas chlororaphis, Bacillus megaterium and endophytic actinomycetes in a mass ratio of (3-5):(1-2):(1-4):(1-2).

[0007] Furthermore, the modified biochar is prepared by the following steps: A1. Treating the beech wood raw material at 300-500° C. for 1-3 hours, then crushing the pyrolyzed beech wood raw material and passing it through an 80-mesh sieve to obtain beech wood powder; and continuing to pyrolyze the beech wood powder at 150-200° C. for 24 hours to obtain beech wood biochar; A2. Mix a silane coupling agent and anhydrous ethanol to obtain a hydrophobic modifier; then add the beech wood biochar obtained in step S1 to the hydrophobic modifier, stir the system evenly at room temperature, and then ultrasonically treat it for 10-20 minutes at an ultrasonic frequency of 18-20 kHz, then continue to soak for 10-30 minutes, filter, and dry the filtrate to obtain modified biochar.

[0008] Furthermore, the modified biochar is prepared by the following steps: A1. Treating the beech wood raw material at 300-500° C. for 1-3 hours, then crushing the pyrolyzed beech wood raw material and passing it through an 80-mesh sieve to obtain beech wood powder; and continuing to pyrolyze the beech wood powder at 150-200° C. for 24 hours to obtain beech wood biochar; A2. Mix a silane coupling agent and anhydrous ethanol in a mass ratio of (1.8-2.5): (97.5-98.2) to obtain a hydrophobic modifier; then add the beech wood biochar obtained in step S1 to the hydrophobic modifier in a dosage ratio of 1 g: 8-10 mL, stir the system evenly at room temperature, and then ultrasonically treat it for 10-20 minutes at an ultrasonic frequency of 18-20 kHz, then continue to soak for 10-30 minutes, filter, and dry the filtrate at 100-120 ° C for 30-60 minutes to obtain modified biochar.

[0009] Furthermore, the acrylate-based sustained-release material is prepared by the following steps: B1. Add carboxymethyl cellulose to deionized water, then add methyl methacrylate and potassium persulfate, and react at 50-60° C. for 3-5 hours to obtain a pre-emulsified system; B2. Take butyl acrylate and methyl methacrylate separately, mix them, and then add them into deionized water; stir the system evenly at room temperature, add the pre-emulsified system, emulsifier, water-soluble sugars, and complex salts obtained in step B1, stir at room temperature for 30-60 minutes, increase the system temperature to 60-80°C, react for 3-5 hours, and adjust the pH value of the system to neutral to obtain an acrylate-based sustained-release material.

[0010] Furthermore, the acrylate-based sustained-release material is prepared by the following steps: B1. Add 0.6 g of carboxymethyl cellulose to deionized water at a mass volume ratio of 1 g:10 mL, then add 0.1-0.3 g of methyl methacrylate and 0.1-0.15 g of potassium persulfate, and react at 50-60° C. for 3-5 hours to obtain a pre-emulsified system; B2. Take butyl acrylate and methyl methacrylate separately, mix them, and then add them into deionized water at a mass ratio of 1g:3mL; stir the system evenly at room temperature, add the pre-emulsified system, emulsifier, water-soluble sugars, and complex salts obtained in step B1, stir at room temperature at a rate of 300-500rpm for 30-60 minutes, increase the system temperature to 60-80°C, react for 3-5 hours, and adjust the pH value of the system to neutral to obtain an acrylate-based sustained-release material.

[0011] In the above reaction process, methyl methacrylate and butyl acrylate are the main monomers, which are copolymerized under the condition of potassium persulfate as an initiator to prepare an acrylate-based sustained-release material. Carboxymethyl cellulose is mainly used as an emulsifier, and water-soluble sugars and complex salts are used as stabilizers to form and stabilize the emulsion system to prepare an acrylate-based sustained-release material.

[0012] Furthermore, in step B1, the mass ratio of carboxymethyl cellulose, methyl methacrylate and potassium persulfate is 0.6:0.1-0.3:0.1-0.15.

[0013] Furthermore, in step B2, the mass ratio of emulsifier, butyl acrylate, methyl methacrylate, water-soluble sugar and complex salt is (0.5-1):(10-12):(8-10):(1-3):(0.2-0.8).

[0014] Furthermore, in step B2, the composite salt is obtained by mixing calcium phosphate, zinc nitrate and calcium carbonate in a mass ratio of (1-3):1:(1-5).

[0015] A method for preparing a composition for improving the lodging resistance of rice comprises the following preparation steps: S1. Inoculate the rhizosphere growth-promoting bacteria into the LB culture medium at an inoculation ratio of 1-3%, shake and culture at a rate of 200-300 rpm, set the culture temperature to 25-30°C, and culture for 24-48 hours to obtain activated bacteria; S2, adding the modified biochar to the activated bacteria, treating at a shaking rate of 200-300 rpm for 30-60 minutes, then centrifuging the system at a rate of 3000-5000 rpm for 5-10 minutes, filtering and resuspending with PBS buffer, centrifuging again at a rate of 3000-5000 rpm for 5-10 minutes, filtering, and obtaining a modified biochar-bacteria complex; S3. Add the modified biochar-bacteria complex and the formula of paclobutrazol and gibberellin in step S2 to the acrylate-based sustained-release material, stir at a rate of 30-90 rpm for 30-60 minutes at room temperature, then place on a polytetrafluoroethylene plate, and dry at 40-50° C. for 24-48 hours to obtain a composition for improving the lodging resistance of rice.

[0016] In summary, this application has the following beneficial effects: In the technical solution of the present invention, paclobutrazol, gibberellins, rhizosphere growth-promoting bacteria, and modified biochar components are compounded to prepare a composition for improving the lodging resistance of rice. Paclobutrazol is a highly active plant growth retardant and broad-spectrum fungicide that can inhibit the biosynthesis of endogenous gibberellins in plants, thereby reducing the content of gibberellins in plants, delaying plant growth, inhibiting stem elongation and shortening internodes. It can also increase the activity of rice indoleacetic acid oxidase, reduce the content of endogenous indoleacetic acid, and increase the release of ethylene, further promote the growth of lateral buds (tillering) of rice, and make the plants dwarfed and compact. This helps to make the rice stalks thick and tough and improve the lodging resistance. Rhizosphere growth-promoting bacteria promote the growth and development of rice roots by improving the soil microecological environment. A healthy root system can enhance the rice's ability to absorb soil nutrients and improve the overall growth of the plant, thereby indirectly enhancing the lodging resistance. Modified biochar has excellent soil improvement properties, which can increase soil porosity, improve soil aeration and water retention. This helps rice roots breathe and grow better and improves root vitality. Gibberellic acid, as a plant hormone, can promote plant growth and regulate the growth and development of rice in the compound component.

[0017] In the technical solution of the present invention, a silane coupling agent is used to hydrophobically modify biochar to prepare modified biochar. The hydrophobic layer formed by the silane coupling agent on the surface of the biochar can enhance the adhesion of the bacterial species, so that the composite bacterial species can be more stably attached to the modified biochar. This stable attachment relationship helps the bacterial species to survive and reproduce in a complex environment, thereby improving its practical application effect. The biochar modified by the silane coupling agent has a better pore structure and surface properties, which is conducive to the growth and metabolism of the bacterial species therein. The good pore structure can provide more attachment points and nutrient channels, and the hydrophobic surface helps to maintain the stability of the microenvironment around the bacterial species, thereby improving the activity and metabolic efficiency of the bacterial species.

[0018] In the technical solution of the present invention, nitrogen-fixing bacteria, Pseudomonas chlororaphis, Bacillus megaterium and endophytic actinomycetes are used for matching. The nitrogen-fixing bacteria provide nitrogen, Bacillus megaterium provides phosphorus and promotes nutrient absorption, and Pseudomonas chlororaphis and endophytic actinomycetes enhance the lodging resistance by promoting root development and stem strength. The modified biochar is used to load the above-mentioned combined strains. As a porous material, biochar has a large specific surface area and adsorption capacity, which can provide stable attachment points and nutrients for the growth of strains, ensuring the survival and reproduction of strains in the soil. The combined effect of biochar and strains can improve soil structure, improve soil aeration and water retention, and provide a better growth environment for rice roots. At the same time, the metabolic activities of the strains can also promote the circulation and utilization of soil nutrients, further improving the lodging resistance of rice.

[0019] In the technical solution of the present invention, the composite salts composed of calcium phosphate, zinc nitrate and calcium carbonate are used to enhance the obtained acrylate-based sustained-release material. Inorganic salts such as calcium phosphate, zinc nitrate and calcium carbonate have good stability and hardness. When they are compounded with acrylate-based materials, the overall structural stability of the material can be effectively enhanced. This stability improvement helps the sustained-release material to maintain its shape and performance in a complex environment, ensuring the continuous and stable release of the drug. The release performance of the sustained-release material can also be regulated by the usage amount of the composite salts. In addition, after the nutrient elements provided in the sustained-release material are transformed by strains, nutrients and other growth regulating substances that are more easily absorbed by plants can be produced, and these substances can promote the synthesis and accumulation of cell wall components in rice stalks. The increase of these components helps to enhance the mechanical strength of the stalks, making rice more stable when facing adverse conditions such as wind and rain. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The specific implementation methods of this application involve: The emulsifier used was OP-10, and the water-soluble sugar was glucose; The silane coupling agent used was hexadecyltrimethoxysilane; Azotobacter: The strain number is CICC 20024; Pseudomonas chlororaphis: CICC 22693; Bacillus megaterium: CICC 21580; Endophytic actinomycetes: provided by Shandong Hezhong Kangyuan Biotechnology Co., Ltd., with a viable count of 10 billion.

[0022] Example 1 A composition for improving the lodging resistance of rice, comprising the following raw materials in parts by weight: 1.3 parts of paclobutrazol, 0.2 parts of gibberellins, 0.1 parts of rhizosphere growth-promoting bacteria, 1 part of modified biochar and 100 parts of acrylate-based slow-release materials; The rhizosphere growth-promoting bacteria were all at a concentration of 1×10 6 CFU / mL of nitrogen-fixing bacteria, Pseudomonas chlororaphis, Bacillus megaterium and endophytic actinomycetes were mixed in a mass ratio of 3:1:1:1.

[0023] Wherein, the modified biochar is prepared by the following steps: A1. The beech wood raw material was treated at 300°C for 1 hour, and then the pyrolyzed beech wood raw material was crushed and passed through an 80-mesh sieve to obtain beech wood powder; the beech wood powder was further pyrolyzed at 150°C for 24 hours to obtain beech wood biochar; A2. Mix a silane coupling agent and anhydrous ethanol in a mass ratio of 1.8:98.2 to obtain a hydrophobic modifier; then add the beech wood biochar obtained in step S1 to the hydrophobic modifier in a dosage ratio of 1 g:8 mL, stir the system evenly at room temperature, and then ultrasonically treat it for 10 minutes at an ultrasonic frequency of 18 kHz, then continue to soak for 10 minutes, filter, and dry the filtrate at 100°C for 30 minutes to obtain modified biochar.

[0024] Wherein, the acrylate-based sustained-release material is prepared by the following steps: B1. 0.6 g of carboxymethyl cellulose was added to deionized water at a mass volume ratio of 1 g:10 mL, followed by the addition of 0.1 g of methyl methacrylate and 0.1 g of potassium persulfate, and the mixture was reacted at 50° C. for 3 hours to obtain a pre-emulsified system; B2. Take another 10g of butyl acrylate and 8g of methyl methacrylate, mix them, and then add them into deionized water at a mass ratio of 1g:3mL; stir the system evenly at room temperature, add the pre-emulsified system obtained in step B1, 0.5g of emulsifier, 1g of water-soluble sugar, and 0.2g of complex salts, stir at room temperature at a rate of 300rpm for 30 minutes, increase the system temperature to 60°C, react for 3 hours, adjust the system pH to neutral, and obtain an acrylate-based sustained-release material; wherein the complex salt is obtained by mixing calcium phosphate, zinc nitrate and calcium carbonate at a mass ratio of 1:1:1.

[0025] A method for preparing a composition for improving the lodging resistance of rice comprises the following preparation steps: S1. Inoculate the rhizosphere growth-promoting bacteria into the LB medium at a 1% inoculation ratio, culture on a shaker at 200 rpm, set the culture temperature to 25°C, and culture for 24 hours to obtain activated strains; S2, adding the modified biochar to the activated bacteria, treating at a shaking rate of 200 rpm for 30 minutes, then centrifuging the system at a rate of 3000 rpm for 5 minutes, filtering and resuspending with PBS buffer, centrifuging again at a rate of 3000 rpm for 5 minutes, filtering, and obtaining a modified biochar-bacteria complex; S3. Add the modified biochar-bacteria complex and the formula of paclobutrazol and gibberellin in step S2 to the acrylate-based sustained-release material, stir at 30 rpm for 30-60 minutes at room temperature, then place on a polytetrafluoroethylene plate, and dry at 40°C for 24 hours to obtain a composition for improving the lodging resistance of rice.

[0026] Example 2 A composition for improving the lodging resistance of rice, comprising the following raw materials in parts by weight: 1.6 parts of paclobutrazol, 0.25 parts of gibberellins, 0.2 parts of rhizosphere growth-promoting bacteria, 3 parts of modified biochar, and 100 parts of acrylate-based slow-release materials; Wherein, the rhizosphere growth-promoting bacteria are 1×10 6 CFU / mL of nitrogen-fixing bacteria, Pseudomonas chlororaphis, Bacillus megaterium and endophytic actinomycetes were mixed in a mass ratio of 4:1.5:2:1.5.

[0027] Wherein, the modified biochar is prepared by the following steps: A1. The beech wood raw material is treated at 400°C for 2 hours, and then the pyrolyzed beech wood raw material is crushed and passed through an 80-mesh sieve to obtain beech wood powder; the beech wood powder is further pyrolyzed at 180°C for 24 hours to obtain beech wood biochar; A2. Mix a silane coupling agent and anhydrous ethanol in a mass ratio of 2:98 to obtain a hydrophobic modifier; then add the beech wood biochar obtained in step S1 to the hydrophobic modifier in a dosage ratio of 1 g:9 mL, stir the system evenly at room temperature, and then ultrasonically treat it for 15 minutes at an ultrasonic frequency of 18 kHz, then continue to soak for 20 minutes, filter, and dry the filtrate at 110°C for 45 minutes to obtain modified biochar.

[0028] Wherein, the acrylate-based sustained-release material is prepared by the following steps: B1. 0.6 g of carboxymethyl cellulose was added to deionized water at a mass volume ratio of 1 g:10 mL, followed by the addition of 0.2 g of methyl methacrylate and 0.12 g of potassium persulfate, and the mixture was reacted at 55° C. for 4 hours to obtain a pre-emulsified system; B2. Take 11g of butyl acrylate and 9g of methyl methacrylate, mix them, and then add them into deionized water at a mass ratio of 1g:3mL; stir the system evenly at room temperature, add the pre-emulsified system obtained in step B1, 0.7g of emulsifier, 2g of water-soluble sugars, and 0.5g of complex salts, stir at room temperature at a rate of 400rpm for 45 minutes, increase the system temperature to 70°C, react for 4 hours, adjust the system pH to neutral, and obtain an acrylate-based sustained-release material; wherein the complex salt is obtained by mixing calcium phosphate, zinc nitrate and calcium carbonate at a mass ratio of 2:1:3.

[0029] A method for preparing a composition for improving the lodging resistance of rice comprises the following preparation steps: S1. Inoculate the rhizosphere growth-promoting bacteria into LB medium at a 2% inoculation ratio, culture on a shaker at 250 rpm, set the culture temperature to 28°C, and culture for 36 hours to obtain activated strains; S2, adding the modified biochar to the activated bacteria, treating at a shaking rate of 250 rpm for 45 minutes, then centrifuging the system at a rate of 4000 rpm for 8 minutes, filtering and resuspending with PBS buffer, centrifuging again at a rate of 4000 rpm for 8 minutes, filtering, and obtaining a modified biochar-bacteria complex; S3. Add the modified biochar-bacteria complex and the formula of paclobutrazol and gibberellin in step S2 to the acrylate-based sustained-release material, stir at 60 rpm for 45 minutes at room temperature, then place on a polytetrafluoroethylene plate, and dry at 45°C for 36 hours to obtain a composition for improving the lodging resistance of rice.

[0030] Example 3 A composition for improving the lodging resistance of rice, comprising the following raw materials in parts by weight: 2 parts of paclobutrazol, 0.3 parts of gibberellins, 0.3 parts of rhizosphere growth-promoting bacteria, 5 parts of modified biochar, and 100 parts of acrylate-based slow-release materials; Wherein, the rhizosphere growth-promoting bacteria are 1×10 6 CFU / mL of nitrogen-fixing bacteria, Pseudomonas chlororaphis, Bacillus megaterium and endophytic actinomycetes were mixed in a mass ratio of 5:2:4:2.

[0031] Wherein, the modified biochar is prepared by the following steps: A1. The beech wood raw material is placed at 500°C for 3 hours, and then the pyrolyzed beech wood raw material is crushed and passed through an 80-mesh sieve to obtain beech wood powder; the beech wood powder is placed at 200°C for 24 hours to obtain beech wood biochar; A2. Mix a silane coupling agent and anhydrous ethanol in a mass ratio of 2.5:97.5 to obtain a hydrophobic modifier; then add the beech wood biochar obtained in step S1 to the hydrophobic modifier in a dosage ratio of 1 g:10 mL, stir the system evenly at room temperature, and then ultrasonically treat it for 20 minutes at an ultrasonic frequency of 20 kHz, then continue to soak for 30 minutes, filter, and dry the filtrate at 120°C for 60 minutes to obtain modified biochar.

[0032] Wherein, the acrylate-based sustained-release material is prepared by the following steps: B1. 0.6 g of carboxymethyl cellulose was added to deionized water at a mass volume ratio of 1 g:10 mL, followed by the addition of 0.3 g of methyl methacrylate and 0.15 g of potassium persulfate, and the mixture was reacted at 60° C. for 5 hours to obtain a pre-emulsified system; B2. Take another 12g of butyl acrylate and 10g of methyl methacrylate, mix them, and then add them into deionized water at a mass ratio of 1g:3mL; stir the system evenly at room temperature, add the pre-emulsified system obtained in step B1, 1g of emulsifier, 3g of water-soluble sugars, and 0.8g of complex salts, stir at room temperature at a rate of 500rpm for 60 minutes, increase the system temperature to 80°C, react for 5 hours, adjust the system pH to neutral, and obtain an acrylate-based sustained-release material; wherein the complex salt is obtained by mixing calcium phosphate, zinc nitrate and calcium carbonate at a mass ratio of 3:1:5.

[0033] A method for preparing a composition for improving the lodging resistance of rice comprises the following preparation steps: S1. Inoculate the rhizosphere growth-promoting bacteria into the LB culture medium at a 3% inoculation ratio, culture on a shaker at 300 rpm, set the culture temperature to 30°C, and culture for 48 hours to obtain activated strains; S2, adding the modified biochar to the activated bacteria, treating at a shaking rate of 300 rpm for 60 minutes, then centrifuging the system at a rate of 5000 rpm for 10 minutes, filtering and resuspending with PBS buffer, centrifuging again at a rate of 5000 rpm for 10 minutes, filtering, and obtaining a modified biochar-bacteria complex; S3. Add the modified biochar-bacteria complex and the formula of paclobutrazol and gibberellin in step S2 to the acrylate-based sustained-release material, stir at 90 rpm for 60 minutes at room temperature, then place on a polytetrafluoroethylene plate, and dry at 50°C for 48 hours to obtain a composition for improving the lodging resistance of rice.

[0034] Comparative Example 1 The difference between this comparative example and Example 1 is that the modified biochar in this comparative example is prepared by the following steps: Wherein, the modified biochar is prepared by the following steps: A1. The beech wood raw material was treated at 300°C for 1 hour, and then the pyrolyzed beech wood raw material was crushed and passed through an 80-mesh sieve to obtain beech wood powder; the beech wood powder was further pyrolyzed at 150°C for 24 hours to obtain beech wood biochar; A2. Prepare 1 mol / L sodium hydroxide solution to obtain a hydrophobic modifier; then add the beech wood biochar obtained in step S1 to the hydrophobic modifier at a ratio of 1 g: 8 mL, stir the system evenly at room temperature, and then ultrasonically treat it for 10 minutes at an ultrasonic frequency of 18 kHz, then continue to soak for 10 minutes, filter, and dry the filtrate at 100° C. for 30 minutes to obtain modified biochar.

[0035] Comparative Example 2 The difference between this comparative example and Example 1 is that the modified biochar in this comparative example is prepared by the following steps: Wherein, the modified biochar is prepared by the following steps: The beech wood raw material is treated at 300°C for 1 hour, and then the pyrolyzed beech wood raw material is crushed and passed through an 80-mesh sieve to obtain beech wood powder; the beech wood powder is continued to be pyrolyzed at 150°C for 24 hours to obtain modified biochar.

[0036] Comparative Example 3 The difference between this comparative example and Example 1 is that the modified biochar in this comparative example is prepared by the following steps: Wherein, the modified biochar is prepared by the following steps: A1. The beech wood raw material was treated at 300°C for 1 hour, and then the pyrolyzed beech wood raw material was crushed and passed through an 80-mesh sieve to obtain beech wood powder; the beech wood powder was further pyrolyzed at 150°C for 24 hours to obtain beech wood biochar; A2. Mix a silane coupling agent and anhydrous ethanol in a mass ratio of 5:95 to obtain a hydrophobic modifier; then add the beech wood biochar obtained in step S1 to the hydrophobic modifier in a dosage ratio of 1 g:8 mL, stir the system evenly at room temperature, and then ultrasonically treat it for 10 minutes at an ultrasonic frequency of 18 kHz, then continue to soak for 10 minutes, filter, and dry the filtrate at 100 ° C for 30 minutes to obtain modified biochar.

[0037] Comparative Example 4 The difference between this comparative example and Example 1 is that in this comparative example, a composition for improving the lodging resistance of rice comprises the following raw materials in parts by weight: 1.5 parts of paclobutrazol, 0.1 parts of rhizosphere growth-promoting bacteria, 1 part of modified biochar and 100 parts of acrylate-based slow-release materials.

[0038] Comparative Example 5 The difference between this comparative example and Example 1 is that in this comparative example, a composition for improving the lodging resistance of rice comprises the following raw materials in parts by weight: 1.4 parts of paclobutrazol, 0.2 parts of gibberellin, 1 part of modified biochar and 100 parts of acrylate-based slow-release materials.

[0039] Comparative Example 6 The difference between this comparative example and Example 1 is that the concentration of the rhizosphere growth-promoting bacteria used in this comparative example is 1×10 6 CFU / mL of nitrogen-fixing bacteria, Pseudomonas chlororaphis and Bacillus megaterium were mixed in a mass ratio of 3:1:2.

[0040] Comparative Example 7 The difference between this comparative example and Example 1 is that the composite salt in this comparative example is obtained by mixing zinc nitrate and calcium carbonate in a mass ratio of 1:1.

[0041] Performance Testing The compositions for improving the lodging resistance of rice prepared in Examples 1-3 and Comparative Examples 1-7 of the present application were mixed with Beifeng 46% rice fertilizer in a mass ratio of 1:10, and applied to rice of the brand Shendao No. 47 at a fertilizer application rate of 30 kg / mu, with full-layer fertilization, 2 / 3 applied when turning the soil, and 1 / 3 applied when harrowing the soil, and topdressing once with Beifeng 46% rice fertilizer after 60 days at an application rate of 30 kg / mu, and harvested after 130 days.

[0042] The enhancing effect of the compositions prepared in different groups on the resistance of rice to lodging is now tested. Twenty rice plants were selected in each test field at harvest time, and the length from the base of the internode to the top of the ear, the fresh weight from the base of the internode to the top of the ear, and the bending resistance were recorded. The specific measurement method of the bending resistance is: Take 15cm from the lower end of the rice and put it into an electronic universal testing machine for compression test using a 20N sensor. The test speed is 6mm / min, and the bending resistance is tested. The lodging resistance coefficient of the rice sample is calculated by the length from the base of the internode to the top of the ear, the fresh weight from the base of the internode to the top of the ear, and the bending resistance data. The yield is calculated after harvesting. The specific performance test results are shown in Table 1: Table 1 Group Lodging resistance coefficient (N·cm-1·g-1) Output (kg / m2) Example 1 0.73 1.83 Example 2 0.70 1.88 Example 3 0.71 1.85 Comparative Example 1 0.74 1.80 Comparative Example 2 0.76 1.81 Comparative Example 3 0.76 1.78 Comparative Example 4 0.83 1.73 Comparative Example 5 0.85 1.70 Comparative Example 6 0.79 1.73 Comparative Example 7 0.80 1.74 As can be seen from the results in Table 1 above, the rice lodging resistance composition prepared in Examples 1-3 of the present application has a significantly better effect on promoting rice than the rice lodging resistance composition prepared in Comparative Examples 1-7, that is, within the technical solution defined in the present application, the comprehensive performance of the prepared composition is excellent. As can be seen from the results in Comparative Examples 1-3, the biochar modified by the silane coupling agent has better performance stability. At the same time, due to the stable attachment of the strains on the modified biochar and the good growth environment, the composite strains can also maintain high activity and efficiency during multiple uses. As can be seen from the results in Comparative Examples 4-5, through the delayed growth and sturdy stem effects of paclobutrazol, combined with the appropriate amount of gibberellin, the root promotion effect of rhizosphere growth-promoting bacteria and the soil improvement effect of modified biochar, the compounding scheme can significantly improve the lodging resistance of rice. As can be seen from the results in Comparative Example 6, the use of nitrogen-fixing bacteria, Pseudomonas chlororaphis, Bacillus megaterium and endophytic actinomycetes is beneficial to improving the yield and lodging resistance of rice. From the results in Comparative Example 7, it can be seen that the use of composite salts composed of calcium phosphate, zinc nitrate and calcium carbonate to enhance the acrylate-based sustained-release material can improve its structural stability, optimize the sustained-release performance and enhance biocompatibility.

[0043] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0044] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A composition for improving the lodging resistance of rice, characterized in that: Including the following raw materials by weight: 1.3-2 parts of paclobutrazol, 0.2-0.3 parts of gibberellins, 0.1-0.3 parts of rhizosphere growth-promoting bacteria, 1-5 parts of modified biochar and 100 parts of acrylate-based slow-release materials; Wherein, the modified biochar is obtained by hydrophobically modifying the biochar with a silane coupling agent.

2. A composition for improving rice lodging resistance according to claim 1, characterized in that: The rhizosphere growth-promoting bacteria are obtained by mixing nitrogen-fixing bacteria, Pseudomonas chlororaphis, Bacillus megaterium and endophytic actinomycetes in a mass ratio of 3-5:1-2:1-4:1-2.

3. A composition for improving rice lodging resistance according to claim 1, characterized in that: The modified biochar is prepared by the following steps: A1. Treating the beech wood raw material at 300-500° C. for 1-3 hours, then crushing the pyrolyzed beech wood raw material and passing it through an 80-mesh sieve to obtain beech wood powder; and continuing to pyrolyze the beech wood powder at 150-200° C. for 24 hours to obtain beech wood biochar; A2. Mix a silane coupling agent and anhydrous ethanol to obtain a hydrophobic modifier; then add the beech wood biochar obtained in step S1 to the hydrophobic modifier, stir the system evenly at room temperature, and then ultrasonically treat it for 10-20 minutes at an ultrasonic frequency of 18-20 kHz, then continue to soak for 10-30 minutes, filter, and dry the filtrate to obtain modified biochar.

4. A composition for improving rice lodging resistance according to claim 1, characterized in that: The acrylate-based sustained-release material is prepared by the following steps: B1. Add carboxymethyl cellulose to deionized water, then add methyl methacrylate and potassium persulfate, and react at 50-60° C. for 3-5 hours to obtain a pre-emulsified system; B2. Take butyl acrylate and methyl methacrylate separately, mix them, and then add them into deionized water; stir the system evenly at room temperature, add the pre-emulsified system, emulsifier, water-soluble sugars, and complex salts obtained in step B1, stir at room temperature for 30-60 minutes, increase the system temperature to 60-80°C, react for 3-5 hours, and adjust the pH value of the system to neutral to obtain an acrylate-based sustained-release material.

5. A composition for improving rice lodging resistance according to claim 4, characterized in that: In step B1, the mass ratio of carboxymethyl cellulose, methyl methacrylate and potassium persulfate is 0.6:0.1-0.3:0.1-0.

15.

6. A composition for improving rice lodging resistance according to claim 4, characterized in that: In step B2, the mass ratio of emulsifier, butyl acrylate, methyl methacrylate, water-soluble sugar and complex salt is 0.5-1:10-12:8-10:1-3:0.2-0.

8.

7. A composition for improving rice lodging resistance according to claim 4, characterized in that: In step B2, the composite salt is obtained by mixing calcium phosphate, zinc nitrate and calcium carbonate in a mass ratio of 1-3:1:1-5.

8. A method for preparing a composition for improving rice lodging resistance as claimed in any one of claims 1 to 7, characterized in that: The method comprises the following preparation steps: S1. Inoculate the rhizosphere growth-promoting bacteria into the LB culture medium at an inoculation ratio of 1-3%, shake and culture at a rate of 200-300 rpm, set the culture temperature to 25-30°C, and culture for 24-48 hours to obtain activated bacteria; S2, adding the modified biochar to the activated bacteria, treating at a shaking rate of 200-300 rpm for 30-60 minutes, then centrifuging the system at a rate of 3000-5000 rpm for 5-10 minutes, filtering and resuspending with PBS buffer, centrifuging again at a rate of 3000-5000 rpm for 5-10 minutes, filtering, and obtaining a modified biochar-bacteria complex; S3. Add the modified biochar-bacteria complex and the formula of paclobutrazol and gibberellin in step S2 to the acrylate-based sustained-release material, stir at a rate of 30-90 rpm for 30-60 minutes at room temperature, then place on a polytetrafluoroethylene plate, and dry at 40-50° C. for 24-48 hours to obtain a composition for improving the lodging resistance of rice.