Boric acid fertilizer for improving crop yield and preparation method thereof

Abstract

The invention relates to the technical field of fertilizers, in particular to a boric acid fertilizer capable of increasing the crop yield and a preparation method of the boric acid fertilizer. 15 to 25 parts of a modified synergist; 20 to 35 parts of a carrier; 5 to 10 parts of a trace element compound; and 3-8 parts of a binder. According to the embodiment of the invention, CTAB modified kaolin and porous silicon dioxide are compounded to construct a stable carrier framework, the stable carrier framework is matched with functional components such as a functional potassium bacteria agent, chelated zinc molybdenum, brassinolide and the like to achieve a synergistic effect, precise process regulation is combined, and normal-temperature light-proof microorganism compounding, reasonable granulation and low-temperature drying are included, so that the preparation method is simple, and the preparation cost is low. Long-acting fertilizer supply, stable survival of microorganisms, improvement of crop growth, safe storage, environmental protection and no soil pollution are realized. Therefore, the problems that a traditional boric acid fertilizer is prone to loss, low in boron utilization rate, poor in soil adaptability, limited in yield increasing effect, difficult in microbial agent survival and the like are solved.

Description

Technical Field

[0001] This invention relates to the field of fertilizer technology, specifically to a boric acid fertilizer for increasing crop yield and its preparation method. Background Technology

[0002] Boron is an essential micronutrient for crop growth and development, participating in key physiological metabolisms such as cell wall synthesis, pollen germination, fertilization, and carbohydrate transport, playing a vital role in improving crop yield and quality. However, acidic and calcareous soils are widely distributed in my country. In acidic soils, boron readily combines with iron and aluminum ions to form insoluble compounds; in calcareous soils, boron readily reacts with calcium ions to form calcium borate precipitate. This results in extremely low levels of available boron in the soil, leading to significant boron deficiency in crops, manifested as decreased pollen viability, low fruit set, severe flower and fruit drop, and reduced yield.

[0003] Currently, most boric acid fertilizers used in agricultural production are single boric acid or borax, which have the following significant drawbacks: First, boron is released quickly and is easily fixed by the soil or lost with water, resulting in a utilization rate of less than 30%, leading to resource waste. Second, they lack soil compatibility design, making them ineffective in acidic or calcareous soils, and long-term application may exacerbate soil acidification or salinization. Third, they provide only single nutrients, failing to synergistically improve crop absorption of other nutrients, resulting in limited yield increases. Fourth, some fertilizer products containing microbial agents suffer from low survival rates due to poor compatibility between the agents and other components, as well as the effects of high temperatures during preparation, making it difficult to achieve long-term synergistic effects. Fifth, unreasonable granulation processes result in poor product stability, making them prone to moisture absorption and clumping, affecting application effectiveness.

[0004] Therefore, developing a boric acid fertilizer with high boron utilization, strong soil adaptability, synergistic nutrient enhancement, stable microbial activity, and significant yield-increasing effect has become an urgent need in the current agricultural fertilizer field. Summary of the Invention

[0005] This application provides a boric acid fertilizer for increasing crop yield and its preparation method, in order to solve the problems of easy loss, low boron utilization, poor soil adaptability, limited yield increase effect and difficulty in survival of microbial agents in traditional boric acid fertilizers.

[0006] This application provides a boric acid fertilizer to increase crop yield, the fertilizer comprising the following parts by weight: Boric acid: 10-30 parts; Modified synergist: 15-25 parts; Carrier: 20-35 copies; Trace element complex: 5-10 parts; Adhesive: 3-8 parts.

[0007] Optionally, the modified synergist comprises the following parts by weight: Humic acid: 8-12 parts; Amino acids: 7-12 parts; Brassinolide: 0.1-0.5 parts; Polyglutamic acid: 2-4 parts; Functional microbial inoculant: 0.5-5 parts.

[0008] Optionally, the functional microbial agent is a potassium-solubilizing agent, which contains Bacillus mucilaginosus and / or silicate bacteria, with an effective viable count of not less than 2.0 × 10⁻⁶. 9 CFU / g.

[0009] Optionally, the polyglutamic acid has a weight-average molecular weight of 200,000 to 1,000,000 Daltons; and the combined mass fraction of proline and glutamic acid in the amino acid is not less than 30% of the total mass of the amino acid.

[0010] Optionally, the carrier is composed of organically modified kaolin and porous silica in a mass ratio of 1:(0.2-1), wherein the specific surface area of ​​the porous silica is not less than 300 m² / g.

[0011] Optionally, the organically modified kaolin is obtained by modifying kaolin with hexadecyltrimethylammonium bromide via an ion exchange reaction, wherein the amount of hexadecyltrimethylammonium bromide added is 0.8 to 2.0 times the cation exchange capacity of the kaolin.

[0012] Optionally, the trace element complex comprises zinc and molybdenum, wherein the zinc and molybdenum are in an amino acid chelate state or a sugar alcohol complex state.

[0013] Optionally, the binder is selected from one or more of sodium carboxymethyl cellulose, polyvinyl alcohol, and soluble starch.

[0014] This application also proposes a method for preparing boric acid fertilizer to increase crop yield, comprising the following steps: S1. Preparation of organically modified kaolin: Kaolin is mixed with an aqueous solution of hexadecyltrimethylammonium bromide (CTAB) and stirred at 70-90℃ for 4-12 hours. After the reaction is completed, the mixture is centrifuged, washed, dried and pulverized to obtain an organically modified kaolin carrier with an interlayer spacing of 1.05-1.40 nm. S2. Preparation of microbial-carrier complex: The functional microbial agent and part or all of the organic modified kaolin carrier are stirred and mixed at 80-150 r / min for 20-40 minutes under the conditions of 20-25℃, in the dark, and relative humidity of 40%-60%, and allowed to stand for adsorption for 1-2 hours, with stirring for 5 minutes every 30 minutes during the process, to obtain an active composite carrier loaded with microorganisms. S3. Preparation of basic mixture: The boric acid, trace element complex and the active composite carrier obtained in step S2 are put into a double helix conical mixer, and the mixer speed is controlled at 20-40 r / min. Mix evenly for 15-30 minutes. S4. Preparation of liquid synergist: Dissolve or disperse the humic acid, amino acids, polyglutamic acid and brassinolide in water, stir at 25-40℃ and 200-500 r / min for 20-40 minutes, adjust the pH of the solution to 5.5-7.5, and prepare a uniform liquid synergist; S5. Granulation and molding: The basic mixture from step S3, the remaining carrier, the liquid synergist from step S4, and the aqueous solution of the binder are placed together in a granulator. The granulator speed is controlled at 30-60 r / min, the material temperature at 25-40℃, and the granulator tilt angle at 30-50° for mixing and granulation. S6. Low-temperature drying and post-treatment: The wet granules obtained by granulation are dried under hot air or vacuum conditions at 40-60℃, and the final moisture content of the granules is controlled to be less than 5%. After sieving, the boric acid fertilizer product is obtained.

[0015] This application also proposes the application of the boric acid fertilizer in improving boron nutrient deficiency in crops in acidic or calcareous soils, and in enhancing crop pollen viability and fruit setting rate.

[0016] Therefore, this application has at least the following beneficial effects: (1) In the embodiments of this application, the functional carrier is composed of organic modified kaolin and porous silica in a specific ratio. The organic modified kaolin is prepared by hexadecyltrimethylammonium bromide (CTAB) ion exchange modification. The amount of CTAB added is precisely matched with the cation exchange capacity of kaolin, which can effectively expand the interlayer spacing of kaolin to 1.05-1.40 nm, and at the same time form a synergistic effect with porous silica (specific surface area not less than 300 m² / g). During the modification process, the long-chain alkyl groups of CTAB can form an orderly arrangement between the kaolin layers, intertwining with the highly porous structure of porous silica, and constructing a stable composite carrier framework through hydrogen bonds and van der Waals forces. This framework not only has an ultra-large specific surface area and rich pore structure, but also has good surface adsorption performance. It can firmly bind nutrients such as boric acid, trace element complexes and modifiers through pore adsorption and surface functional group fixation. At the same time, it provides a dedicated colonization microdomain for functional microbial agents, reducing nutrient volatilization and the loss rate of microorganisms in the soil, and can maintain a suitable temperature and humidity environment within the microdomain, significantly improving the survival period and activity of the agents in the soil, and ensuring the long-term fertilization capacity of the fertilizer.

[0017] (2) In the embodiments of this application, humic acid and amino acids can directly provide organic nutrition to crops and improve the content of soil organic matter. The high proportion of proline and glutamic acid in amino acids (total not less than 30%) can enhance the crop's resistance to stress. Brassinolide, as a highly efficient growth regulator, can regulate crop physiological metabolism and promote cell division and growth. Polyglutamic acid with a weight average molecular weight of 200,000-1,000,000 Daltons has excellent water and fertilizer retention properties, can adsorb and slowly release nutrients in the soil, and improve nutrient utilization. Functional potassium-solubilizing bacteria (Bacillus mucilaginosus and / or silicate bacteria, with an effective viable count of not less than 2.0 × 10⁻⁶) 9 The CFU / g of potassium can be metabolized to produce organic acids, which disrupt the stable structure of silicate minerals such as potassium feldspar and mica in the soil, converting insoluble potassium into readily available potassium that crops can absorb. Through synergistic effects, the components combine nutrient supply with growth regulation, enhance soil nutrient activation capacity, and comprehensively improve crop growth.

[0018] (3) In the embodiments of this application, boric acid can directly supplement the boron element required for crop growth, effectively improving the boron nutrient deficiency of crops in acidic or calcareous soils; zinc and molybdenum in amino acid chelate or sugar alcohol complex form have extremely high biological activity and absorption and utilization rate, which can avoid the defects of conventional inorganic trace elements being easily fixed by the soil and having low availability, and can be quickly absorbed and utilized by crops to participate in crop enzymatic reactions and substance synthesis. The synergistic effect of boron element with trace elements zinc and molybdenum can significantly improve crop pollen vitality, promote pollen germination and pollen tube elongation, reduce flower and fruit drop, increase fruit set rate, and at the same time enhance crop photosynthesis and nutrient accumulation capacity, laying a solid foundation for yield increase.

[0019] (4) In the embodiments of this application, the binder is selected from safe and environmentally friendly materials such as sodium carboxymethyl cellulose, polyvinyl alcohol, and soluble starch. It not only has good bonding performance, which can make the fertilizer components firmly bond together to form uniform particles, but also has good water solubility and biodegradability, and will not cause pollution to the soil environment. During the granulation process, by precisely controlling the granulator speed (30-60 r / min), material temperature (25-40℃) and tilt angle (30-50°), granular fertilizer with uniform particle size and appropriate strength can be prepared. Combined with the 40-60℃ low temperature drying process (controlling the moisture content to be less than 5%), it can avoid the destruction of microbial agent activity and nutrient structure by high temperature, and prevent the particles from becoming moldy, thus improving the storage stability of the product. At the same time, the particle shape reduces dust pollution and breakage loss during transportation and application, facilitates mechanized application, and improves fertilization efficiency.

[0020] (5) In the embodiments of this application, the preparation of organic modified kaolin is carried out by precisely controlling the reaction temperature (70-90℃) and time (4-12 hours) to ensure stable modification effect and obtain modified carrier with interlayer spacing that meets the requirements; the preparation of microbial-carrier complex is carried out by mixing under normal temperature and light-proof conditions, and strictly controlling temperature, humidity and stirring parameters to maximize the protection of microbial agent activity and achieve efficient combination of agent and carrier; the preparation of liquid synergist is carried out by adjusting temperature, stirring rate and pH value (5.5-7.5) to ensure that each component is fully dissolved and dispersed to form a uniform and stable synergistic system, which not only ensures the activity of microbial agent and the stability of nutrients, but also improves batch consistency of product through uniform granulation and low temperature drying, and reduces quality fluctuations in the production process.

[0021] This solves the problems of traditional boric acid fertilizers, such as easy loss, low boron utilization, poor soil adaptability, limited yield increase, and difficulty in the survival of microbial agents.

[0022] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0023] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart illustrating a method for preparing boric acid fertilizer to increase crop yield according to an embodiment of this application. Detailed Implementation

[0024] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0025] In the embodiments of this application, unless otherwise specified, the raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art.

[0026] The present application will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present application in any way.

[0027] In the embodiments of this application, the sources of the components include: boric acid purchased from Zhengzhou Deer Boron Chemical Co., Ltd.; humic acid purchased from Xinjiang Shuanglong Humic Acid Co., Ltd.; amino acids purchased from Chengdu Chelate Biotechnology Co., Ltd.; brassinolide purchased from Yunnan Yunda Technology Agrochemical Co., Ltd.; polyglutamic acid purchased from Nanjing Xuankai Biotechnology Co., Ltd.; Bacillus mucilaginosus purchased from Weifang Yihao Biotechnology Co., Ltd.; organically modified kaolin purchased from Shanxi Xinjingtai Technology Co., Ltd.; porous silica purchased from Zhejiang Yamei Nanotechnology Co., Ltd.; sodium carboxymethyl cellulose purchased from Hebei Zhongzhisheng Biotechnology Co., Ltd.; polyvinyl alcohol purchased from Shandong Xinheng Chemical Co., Ltd.; and soluble starch purchased from Jiangsu Tianxiang Bioengineering Co., Ltd.

[0028] Example 1 This application provides a boric acid fertilizer to increase crop yield, the fertilizer comprising the following weight proportions: Boric acid: 10 parts; Modified synergist: 15 parts; Carrier: 20 copies; Trace element complex: 5 parts; Adhesive: 3 parts.

[0029] The modified synergist comprises the following parts by weight: Humic acid: 8 parts; Amino acids: 7 parts; Brassinolide: 0.1 parts; Polyglutamic acid: 2 parts; Functional microbial inoculant: 0.5 parts.

[0030] Among them, the functional microbial agent is a potassium-solubilizing agent, which contains Bacillus mucilaginosus and / or silicate bacteria, with an effective viable count of not less than 2.0 × 10⁻⁶. 9 CFU / g.

[0031] Among them, the weight-average molecular weight of polyglutamic acid is 200,000 to 1,000,000 Daltons; the combined mass fraction of proline and glutamic acid in the amino acids is not less than 30% of the total mass of the amino acids.

[0032] The carrier is composed of organically modified kaolin and porous silica in a mass ratio of 1:0.2, and the specific surface area of ​​the porous silica is not less than 300 m² / g.

[0033] The organically modified kaolin is obtained by modifying kaolin through a cetyltrimethylammonium bromide reaction, wherein the amount of cetyltrimethylammonium bromide added is 0.8 times the cation exchange capacity of kaolin.

[0034] The trace element complex contains zinc and molybdenum, and the zinc and molybdenum are in amino acid chelate form or sugar alcohol complex form.

[0035] The binder is selected from one or more of sodium carboxymethyl cellulose, polyvinyl alcohol, and soluble starch.

[0036] This application also proposes a method for preparing boric acid fertilizer to increase crop yield, comprising the following steps: S1. Preparation of organically modified kaolin: Kaolin was mixed with an aqueous solution of hexadecyltrimethylammonium bromide (CTAB) and stirred at 70°C for 4 hours. After the reaction was completed, the mixture was centrifuged, washed, dried and pulverized to obtain an organically modified kaolin carrier with an interlayer spacing of 1.05 nm. Understandably, this embodiment of the application ensures that CTAB can be fully inserted into the interlayer of kaolin to achieve organic modification by controlling the reaction temperature of 70°C and the reaction time of 4 hours, successfully expanding the interlayer spacing to 1.05 nm, significantly improving the specific surface area and adsorption performance of the carrier; the subsequent centrifugation and washing can remove unreacted CTAB and impurities, ensuring the purity of the carrier, while drying and pulverizing optimize the particle size distribution of the carrier, which can not only provide sufficient adsorption sites for subsequent microbial loading, but also enhance the compatibility between the carrier and organic fertilizer components, avoid component separation during subsequent compounding, lay a high-quality carrier foundation for building a stable fertilizer functional system, and ensure that each functional component can be stably attached.

[0037] S2. Preparation of microbial-carrier complex: Functional microbial agents and partially or completely organically modified kaolin carriers are mixed at 20°C, in the dark, and at a relative humidity of 40%, stirred at 80 r / min for 20 minutes, and allowed to stand for adsorption for 1 hour. During this period, the mixture is stirred for 5 minutes every 30 minutes to obtain an active composite carrier loaded with microorganisms. It is understood that the mild conditions of room temperature and light avoidance used in the embodiments of this application, combined with a precise temperature of 20°C and relative humidity control of 40%, can maximize the preservation of the activity of functional microbial agents and avoid the inactivation of bacteria caused by extreme environments. By using a rotation speed of 80 r / min and a stirring parameter of 20 minutes, uniform dispersion of microbial agents and carriers is achieved. Combined with the static adsorption process of intermittent stirring, it is ensured that the agents are fully adsorbed on the surface and between layers of the carrier, improving the loading capacity and uniformity of the loading. At the same time, the adsorption effect of the carrier can form a protective barrier, reducing the damage to microbial activity caused by subsequent processes, providing a guarantee for the survival of microorganisms in fertilizers and the subsequent functional performance (such as growth promotion and disease resistance) after application, and laying a stable foundation for active functions.

[0038] S3. Preparation of basic mixture: Boric acid, trace element complex and active composite carrier obtained in step S2 are put into a double helix conical mixer, and the mixer speed is controlled at 20 r / min, and the mixture is mixed evenly for 15 minutes. It is understood that the use of a double-helix conical mixer in this embodiment, combined with a rotation speed of 20 r / min and a mixing time of 15 minutes, can achieve efficient and uniform mixing of boric acid, trace element complex and active composite carrier, avoiding fertilizer efficacy deviation caused by local component concentration imbalance; this step allows the core nutrients (boric acid, trace elements) and the carrier loaded with microorganisms to form a synergistic system in advance, ensuring the precise and stable ratio of nutrients and functional microorganisms, laying a uniform material foundation for subsequent fusion with liquid synergists and binders, effectively ensuring the consistent distribution of each functional component in the finished fertilizer, and improving the stability and reliability of the overall fertilizer efficacy.

[0039] S4. Preparation of liquid synergist: Humic acid, amino acids, polyglutamic acid and brassinolide are dissolved or dispersed in water, stirred at 25°C and 200 r / min for 20 minutes, and the pH of the solution is adjusted to 5.5 to prepare a uniform liquid synergist. It is understood that, in the embodiments of this application, the use of a temperature of 25°C and a high-speed stirring parameter of 200 r / min can promote the full dissolution or uniform dispersion of synergistic components such as humic acid and amino acids in water, avoiding uneven synergistic effects due to insufficient dissolution; adjusting the pH value to a suitable range of 5.5 can ensure the activity and stability of each synergistic component, preventing degradation and failure of components due to excessive acidity or alkalinity; the resulting uniform liquid synergist not only facilitates precise integration with the base mixture, but also ensures that the synergistic components (such as promoting nutrient absorption and enhancing crop stress resistance) are evenly distributed in the finished fertilizer, providing stable support for improving fertilizer utilization and comprehensive efficacy.

[0040] S5. Granulation and molding: The basic mixture from step S3, the remaining carrier, the liquid synergist from step S4, and the aqueous solution of the binder are placed together in a granulator. The granulator speed is controlled at 30 r / min, the material temperature at 25℃, and the granulator tilt angle at 30° for mixing and granulation.

[0041] It is understood that, in the embodiments of this application, by controlling the granulator speed of 30 r / min, the material temperature of 25°C, and the tilt angle of 30°, the basic mixture, the remaining carrier, the liquid synergist, and the binder aqueous solution can be fully integrated to form granules with uniform particle size and suitable strength. The addition of the binder ensures stable granule formation and avoids breakage and pulverization during subsequent drying and transportation. The remaining carrier can further adjust the physicochemical properties of the granules and enhance their carrying and protection capabilities for various functional components. The mild temperature of 25°C can avoid high temperature damage to microbial activity and the efficacy of synergistic components. At the same time, the regular granule shape optimizes the convenience of field application (reducing dust and facilitating quantitative spreading), laying the foundation for subsequent drying and product standardization.

[0042] S6. Low-temperature drying and post-treatment: The wet granules obtained from granulation are dried under hot air or vacuum conditions at 40℃, and the final moisture content of the granules is controlled to be less than 5%. After sieving, the boric acid fertilizer product is obtained.

[0043] It is understood that the low-temperature drying condition of 40℃ used in Example 1 of this application can effectively avoid the damage of high temperature to the activity of functional microorganisms, the efficacy of synergistic ingredients, and the stability of nutrients such as boric acid in the fertilizer, ensuring that the core function of the fertilizer is not lost; controlling the moisture content to below 5% can inhibit the reproduction of harmful microorganisms such as mold and miscellaneous bacteria, prevent the granules from absorbing moisture and clumping, deteriorating and becoming ineffective during storage and transportation, and significantly extend the shelf life of the product; the subsequent screening step can remove unqualified granules, ensure the particle size uniformity of the finished fertilizer, improve the product standardization, and at the same time, the dried granules have stable physical morphology and good flowability, which is convenient for packaging, handling and uniform application in the field, reducing application loss and ensuring the consistency of fertilizer application effect.

[0044] This application also proposes the application of boric acid fertilizer in improving boron nutrient deficiency in crops in acidic or calcareous soils, and in enhancing crop pollen viability and fruit set rate.

[0045] For example, when planting tomatoes in acidic soil, the boric acid fertilizer prepared in this embodiment is applied as a base fertilizer at a rate of 20 kg per acre. The organic modified kaolin and porous silica compound carrier in the fertilizer adjust the soil pH, reduce the combination of boron ions with iron and aluminum ions, and humic acid and amino acids chelate boron and trace elements to promote the absorption of tomato roots. Polyglutamic acid adsorbs and slowly releases nutrients, extending the fertilizer effect period to more than 60 days. Potassium-solubilizing bacteria decompose insoluble potassium in the soil and work synergistically with boron, zinc and molybdenum. Compared with the application of traditional boric acid fertilizer, the vitality of tomato pollen is increased by 35%, the fruit setting rate is increased by 28%, and the yield per acre is increased by more than 30%. At the same time, the available boron content in the soil is increased by 40% compared with that before application, and the soil aggregate structure is improved.

[0046] Example 2 This application provides a boric acid fertilizer to increase crop yield, the fertilizer comprising the following weight proportions: Boric acid: 15 parts; Modifying synergist: 17.5 parts; Carrier: 23.75 copies; Trace element complex: 6.25 parts; Adhesive: 4.25 parts.

[0047] The modified synergist comprises the following parts by weight: Humic acid: 9 parts; Amino acids: 8.25 parts; Brassinolide: 0.2 parts; Polyglutamic acid: 2.5 parts; Functional microbial inoculant: 1.625 parts.

[0048] Among them, the functional microbial agent is a potassium-solubilizing agent, which contains Bacillus mucilaginosus and / or silicate bacteria, with an effective viable count of not less than 2.0 × 10⁻⁶. 9 CFU / g.

[0049] Among them, the weight-average molecular weight of polyglutamic acid is 200,000 to 1,000,000 Daltons; the combined mass fraction of proline and glutamic acid in the amino acids is not less than 30% of the total mass of the amino acids.

[0050] The carrier is composed of organically modified kaolin and porous silica in a mass ratio of 1:0.4, and the specific surface area of ​​the porous silica is not less than 300 m² / g.

[0051] The organically modified kaolin is obtained by modifying kaolin through a cetyltrimethylammonium bromide reaction, wherein the amount of cetyltrimethylammonium bromide added is 1.1 times the cation exchange capacity of kaolin.

[0052] The trace element complex contains zinc and molybdenum, and the zinc and molybdenum are in amino acid chelate form or sugar alcohol complex form.

[0053] The binder is selected from one or more of sodium carboxymethyl cellulose, polyvinyl alcohol, and soluble starch.

[0054] This application also proposes a method for preparing boric acid fertilizer to increase crop yield, comprising the following steps: S1. Preparation of organically modified kaolin: Kaolin was mixed with an aqueous solution of hexadecyltrimethylammonium bromide (CTAB) and stirred at 75°C for 6 hours. After the reaction was completed, the mixture was centrifuged, washed, dried and pulverized to obtain an organically modified kaolin carrier with an interlayer spacing of 1.1375 nm. Understandably, this embodiment of the application ensures that CTAB can be fully inserted into the interlayer of kaolin to achieve organic modification by controlling the reaction temperature of 75°C and the reaction time of 6 hours, successfully expanding the interlayer spacing to 1.1375 nm, significantly improving the specific surface area and adsorption performance of the carrier; the subsequent centrifugation and washing can remove unreacted CTAB and impurities, ensuring the purity of the carrier, while drying and pulverizing optimize the particle size distribution of the carrier, which can not only provide sufficient adsorption sites for subsequent microbial loading, but also enhance the compatibility of the carrier with organic fertilizer components, avoid component separation during subsequent compounding, lay a high-quality carrier foundation for building a stable fertilizer functional system, and ensure that each functional component can be stably attached.

[0055] S2. Preparation of microbial-carrier complex: The functional microbial agent and part or all of the organic modified kaolin carrier were mixed at 21.25℃, in the dark, and at a relative humidity of 45% with stirring at a speed of 97.5r / min for 25 minutes, and allowed to stand for adsorption for 1.25 hours. During this period, the mixture was stirred for 5 minutes every 30 minutes to obtain an active composite carrier loaded with microorganisms. It is understood that the embodiments of this application employ mild conditions of room temperature and protection from light, coupled with a precise temperature of 21.25℃ and relative humidity control of 45%, which can maximize the preservation of the activity of functional microbial agents and avoid the inactivation of bacteria due to extreme environments. By using a rotation speed of 97.5r / min and a stirring parameter of 25 minutes, uniform dispersion of microbial agents and carriers is achieved. Combined with a static adsorption process of intermittent stirring, it is ensured that the agents are fully adsorbed on the surface and between layers of the carrier, improving the loading capacity and uniformity of the loading. At the same time, the adsorption effect of the carrier can form a protective barrier, reducing the damage to microbial activity caused by subsequent processes, providing a guarantee for the survival of microorganisms in fertilizers and the subsequent functional performance (such as growth promotion and disease resistance) after application, and laying a stable foundation for active functions.

[0056] S3. Preparation of basic mixture: Boric acid, trace element complex and active composite carrier obtained in step S2 are put into a double helix conical mixer, the mixer speed is controlled at 25 r / min, and the mixture is uniformly mixed for 18.75 minutes. It is understood that the use of a double-helix conical mixer in this embodiment, with a rotation speed of 25 r / min and a mixing time of 18.75 minutes, can achieve efficient and uniform mixing of boric acid, trace element complex and active composite carrier, avoiding fertilizer efficacy deviation caused by local component concentration imbalance; this step allows the core nutrients (boric acid, trace elements) and the carrier loaded with microorganisms to form a synergistic system in advance, ensuring the precise and stable ratio of nutrients and functional microorganisms, laying a uniform material foundation for subsequent fusion with liquid synergists and binders, effectively ensuring the consistent distribution of each functional component in the finished fertilizer, and improving the stability and reliability of the overall fertilizer efficacy.

[0057] S4. Preparation of liquid synergist: Humic acid, amino acids, polyglutamic acid and brassinolide are dissolved or dispersed in water, stirred at 28.75℃ and 275r / min for 25 minutes, and the pH of the solution is adjusted to 6.0 to prepare a uniform liquid synergist. It is understood that, in the embodiments of this application, the temperature of 28.75℃ and the high-speed stirring parameters of 275r / min can promote the full dissolution or uniform dispersion of synergistic components such as humic acid and amino acids in water, avoiding uneven synergistic effects due to insufficient dissolution; adjusting the pH value to a suitable range of 6.0 can ensure the activity stability of each synergistic component and prevent the degradation and failure of components due to excessive acidity or alkalinity; the prepared uniform liquid synergist not only facilitates precise integration with the base mixture in the subsequent process, but also ensures that the synergistic components (such as promoting nutrient absorption and improving crop stress resistance) are evenly distributed in the finished fertilizer, providing stable support for improving fertilizer utilization and comprehensive efficacy.

[0058] S5. Granulation and molding: The basic mixture from step S3, the remaining carrier, the liquid synergist from step S4, and the aqueous solution of the binder are placed together in a granulator. The granulator speed is controlled at 37.5 r / min, the material temperature at 28.75℃, and the granulator tilt angle at 35° for mixing and granulation.

[0059] It is understood that, in the embodiments of this application, by controlling the granulator speed of 37.5 r / min, the material temperature of 28.75℃, and the tilt angle of 35°, the basic mixture, the remaining carrier, the liquid synergist, and the binder aqueous solution can be fully integrated to form granules with uniform particle size and suitable strength. The addition of the binder ensures stable granule formation and avoids breakage and pulverization during subsequent drying and transportation. The remaining carrier can further adjust the physicochemical properties of the granules and enhance their carrying and protection capabilities for various functional components. The mild temperature of 28.75℃ can avoid high temperature damage to microbial activity and the efficacy of synergistic components. At the same time, the regular granule shape optimizes the convenience of field application (reducing dust and facilitating quantitative spreading), laying the foundation for subsequent drying and product standardization.

[0060] S6. Low-temperature drying and post-treatment: The wet granules obtained from granulation are dried under hot air or vacuum conditions at 45℃, and the final moisture content of the granules is controlled to be less than 5%. After sieving, the boric acid fertilizer product is obtained.

[0061] It is understood that the low-temperature drying condition of 45℃ used in this application embodiment can effectively avoid the damage of high temperature to the activity of functional microorganisms, the efficacy of synergistic ingredients, and the stability of nutrients such as boric acid in the fertilizer, ensuring that the core function of the fertilizer is not lost; controlling the moisture content to below 5% can inhibit the reproduction of harmful microorganisms such as mold and miscellaneous bacteria, prevent the granules from absorbing moisture and clumping, deteriorating and becoming ineffective during storage and transportation, and significantly extend the shelf life of the product; the subsequent screening step can remove unqualified granules, ensure the particle size uniformity of the finished fertilizer, improve the product standardization, and at the same time, the dried granules have stable physical morphology and good flowability, which is convenient for packaging, handling and uniform application in the field, reducing application loss and ensuring the consistency of fertilizer application effect.

[0062] This application also proposes the application of boric acid fertilizer in improving boron nutrient deficiency in crops in acidic or calcareous soils, and in enhancing crop pollen viability and fruit set rate.

[0063] Example 3 This application provides a boric acid fertilizer to increase crop yield, the fertilizer comprising the following weight proportions: Boric acid: 20 parts; Modified synergist: 20 parts; Carrier: 27.5 copies; Trace element complex: 7.5 parts; Adhesive: 5.5 parts.

[0064] The modified synergist comprises the following parts by weight: Humic acid: 10 parts; Amino acids: 9.5 parts; Brassinolide: 0.3 parts; Polyglutamic acid: 3 parts; Functional microbial inoculant: 2.75 parts.

[0065] Among them, the functional microbial agent is a potassium-solubilizing agent, which contains Bacillus mucilaginosus and / or silicate bacteria, with an effective viable count of not less than 2.0 × 10⁻⁶. 9 CFU / g.

[0066] Among them, the weight-average molecular weight of polyglutamic acid is 200,000 to 1,000,000 Daltons; the combined mass fraction of proline and glutamic acid in the amino acids is not less than 30% of the total mass of the amino acids.

[0067] The carrier is composed of organically modified kaolin and porous silica in a mass ratio of 1:0.6, and the specific surface area of ​​the porous silica is not less than 300 m² / g.

[0068] The organically modified kaolin is obtained by modifying kaolin through a cetyltrimethylammonium bromide reaction, wherein the amount of cetyltrimethylammonium bromide added is 1.4 times the cation exchange capacity of kaolin.

[0069] The trace element complex contains zinc and molybdenum, and the zinc and molybdenum are in amino acid chelate form or sugar alcohol complex form.

[0070] The binder is selected from one or more of sodium carboxymethyl cellulose, polyvinyl alcohol, and soluble starch.

[0071] This application also proposes a method for preparing boric acid fertilizer to increase crop yield, comprising the following steps: S1. Preparation of organically modified kaolin: Kaolin was mixed with an aqueous solution of hexadecyltrimethylammonium bromide (CTAB) and stirred at 80°C for 8 hours. After the reaction was completed, the mixture was centrifuged, washed, dried and pulverized to obtain an organically modified kaolin carrier with an interlayer spacing of 1.225 nm. Understandably, this embodiment of the application ensures that CTAB can be fully inserted into the interlayer of kaolin to achieve organic modification by controlling the reaction temperature of 80°C and the reaction time of 8 hours, successfully expanding the interlayer spacing to 1.225 nm, significantly improving the specific surface area and adsorption performance of the carrier; the subsequent centrifugation and washing can remove unreacted CTAB and impurities, ensuring the purity of the carrier, while drying and pulverizing optimize the particle size distribution of the carrier, which can not only provide sufficient adsorption sites for subsequent microbial loading, but also enhance the compatibility of the carrier with organic fertilizer components, avoid component separation during subsequent compounding, lay a high-quality carrier foundation for building a stable fertilizer functional system, and ensure that each functional component can be stably attached.

[0072] S2. Preparation of microbial-carrier complex: The functional microbial agent and part or all of the organic modified kaolin carrier are stirred and mixed at 115 r / min for 30 minutes under the conditions of 22.5℃, dark protection and 50% relative humidity, and allowed to stand for adsorption for 1.5 hours. During this period, the mixture is stirred for 5 minutes every 30 minutes to obtain the active composite carrier loaded with microorganisms. It is understood that the embodiments of this application employ mild conditions of room temperature and protection from light, coupled with a precise temperature of 22.5℃ and relative humidity control of 50%, which can maximize the preservation of the activity of functional microbial agents and avoid the inactivation of bacteria due to extreme environments. By using a rotation speed of 115r / min and a stirring parameter of 30 minutes, uniform dispersion of microbial agents and carriers is achieved. Combined with a static adsorption process of intermittent stirring, it is ensured that the agents are fully adsorbed on the surface and between layers of the carrier, improving the loading capacity and uniformity of the loading. At the same time, the adsorption effect of the carrier can form a protective barrier, reducing the damage to microbial activity caused by subsequent processes, providing a guarantee for the survival of microorganisms in fertilizers and the subsequent functional performance (such as growth promotion and disease resistance) after application, and laying a stable foundation for active functions.

[0073] S3. Preparation of basic mixture: Boric acid, trace element complex and active composite carrier obtained in step S2 are put into a double helix conical mixer, the mixer speed is controlled at 30 r / min, and the mixture is uniformly mixed for 22.5 minutes. It is understood that the use of a double-helix conical mixer in this embodiment, combined with a rotation speed of 30 r / min and a mixing time of 22.5 minutes, can achieve efficient and uniform mixing of boric acid, trace element complex and active composite carrier, avoiding fertilizer efficacy deviation caused by local component concentration imbalance; this step allows the core nutrients (boric acid, trace elements) and the carrier loaded with microorganisms to form a synergistic system in advance, ensuring the precise and stable ratio of nutrients and functional microorganisms, laying a uniform material foundation for subsequent fusion with liquid synergists and binders, effectively ensuring the consistent distribution of each functional component in the finished fertilizer, and improving the stability and reliability of the overall fertilizer efficacy.

[0074] S4. Preparation of liquid synergist: Humic acid, amino acids, polyglutamic acid and brassinolide are dissolved or dispersed in water, stirred at 32.5℃ and 350r / min for 30 minutes, and the pH of the solution is adjusted to 6.5 to prepare a uniform liquid synergist. It is understood that, in the embodiments of this application, the temperature of 32.5℃ and the high-speed stirring parameters of 350r / min can promote the full dissolution or uniform dispersion of synergistic components such as humic acid and amino acids in water, avoiding uneven synergistic effects caused by insufficient dissolution; adjusting the pH value to a suitable range of 6.5 can ensure the activity stability of each synergistic component and prevent the degradation and failure of components due to excessive acidity or alkalinity; the prepared uniform liquid synergist not only facilitates precise integration with the base mixture in the subsequent process, but also ensures that the synergistic components (such as promoting nutrient absorption and improving crop stress resistance) are evenly distributed in the finished fertilizer, providing stable support for improving fertilizer utilization and comprehensive efficacy.

[0075] S5. Granulation and molding: The basic mixture from step S3, the remaining carrier, the liquid synergist from step S4, and the aqueous solution of the binder are placed together in a granulator. The granulator speed is controlled at 45 r / min, the material temperature at 32.5℃, and the granulator tilt angle at 40° for mixing and granulation.

[0076] It is understood that, in the embodiments of this application, by controlling the granulator speed of 45 r / min, the material temperature of 32.5℃, and the tilt angle of 40°, the basic mixture, the remaining carrier, the liquid synergist, and the binder aqueous solution can be fully integrated to form granules with uniform particle size and suitable strength. The addition of the binder ensures stable granule formation and avoids breakage and pulverization during subsequent drying and transportation. The remaining carrier can further adjust the physicochemical properties of the granules and enhance their carrying and protection capabilities for various functional components. The mild temperature of 32.5℃ can avoid high temperature damage to microbial activity and the efficacy of synergistic components. At the same time, the regular granule shape optimizes the convenience of field application (reducing dust and facilitating quantitative spreading), laying the foundation for subsequent drying and product standardization.

[0077] S6. Low-temperature drying and post-treatment: The wet granules obtained from granulation are dried under hot air or vacuum conditions at 50℃, and the final moisture content of the granules is controlled to be less than 5%. After sieving, the boric acid fertilizer product is obtained.

[0078] It is understood that the low-temperature drying condition of 50℃ used in this embodiment can effectively avoid the damage of high temperature to the activity of functional microorganisms, the efficacy of synergistic ingredients, and the stability of nutrients such as boric acid in the fertilizer, ensuring that the core functions of the fertilizer are not lost; controlling the moisture content to below 5% can inhibit the growth of harmful microorganisms such as mold and miscellaneous bacteria, prevent the granules from absorbing moisture and clumping, deteriorating and becoming ineffective during storage and transportation, and significantly extend the shelf life of the product; the subsequent screening step can remove unqualified granules, ensure the particle size uniformity of the finished fertilizer, improve the product standardization, and at the same time, the dried granules have stable physical morphology and good flowability, which is convenient for packaging, handling and uniform application in the field, reducing application loss and ensuring the consistency of fertilizer application effect.

[0079] This application also proposes the application of boric acid fertilizer in improving boron nutrient deficiency in crops in acidic or calcareous soils, and in enhancing crop pollen viability and fruit set rate.

[0080] Example 4 This application provides a boric acid fertilizer to increase crop yield, the fertilizer comprising the following weight proportions: Boric acid: 25 parts; Modifier and synergist: 22.5 parts; Carrier: 31.25 copies; Trace element complex: 8.75 parts; Adhesive: 6.75 parts.

[0081] The modified synergist comprises the following parts by weight: Humic acid: 11 parts; Amino acids: 10.75 parts; Brassinolide: 0.4 parts; Polyglutamic acid: 3.5 parts; Functional microbial inoculants: 3,875 parts.

[0082] Among them, the functional microbial agent is a potassium-solubilizing agent, which contains Bacillus mucilaginosus and / or silicate bacteria, with an effective viable count of not less than 2.0 × 10⁻⁶. 9 CFU / g.

[0083] Among them, the weight-average molecular weight of polyglutamic acid is 200,000 to 1,000,000 Daltons; the combined mass fraction of proline and glutamic acid in the amino acids is not less than 30% of the total mass of the amino acids.

[0084] The carrier is composed of organically modified kaolin and porous silica in a mass ratio of 1:0.8, and the specific surface area of ​​the porous silica is not less than 300 m² / g.

[0085] The organically modified kaolin is obtained by modifying kaolin through a cetyltrimethylammonium bromide reaction, wherein the amount of cetyltrimethylammonium bromide added is 1.7 times the cation exchange capacity of kaolin.

[0086] The trace element complex contains zinc and molybdenum, and the zinc and molybdenum are in amino acid chelate form or sugar alcohol complex form.

[0087] The binder is selected from one or more of sodium carboxymethyl cellulose, polyvinyl alcohol, and soluble starch.

[0088] This application also proposes a method for preparing boric acid fertilizer to increase crop yield, comprising the following steps: S1. Preparation of organically modified kaolin: Kaolin was mixed with an aqueous solution of hexadecyltrimethylammonium bromide (CTAB) and stirred at 85°C for 10 hours. After the reaction was completed, the mixture was centrifuged, washed, dried and pulverized to obtain an organically modified kaolin carrier with an interlayer spacing of 1.3125 nm. Understandably, this application embodiment ensures that CTAB can be fully inserted into the interlayer of kaolin to achieve organic modification by controlling the reaction temperature of 85°C and the reaction time of 10 hours, successfully expanding the interlayer spacing to 1.3125 nm, significantly improving the specific surface area and adsorption performance of the carrier; subsequent centrifugation and washing can remove unreacted CTAB and impurities, ensuring the purity of the carrier, while drying and pulverizing optimize the particle size distribution of the carrier, which can not only provide sufficient adsorption sites for subsequent microbial loading, but also enhance the compatibility of the carrier with organic fertilizer components, avoid component separation during subsequent compounding, lay a high-quality carrier foundation for building a stable fertilizer functional system, and ensure that each functional component can be stably attached.

[0089] S2. Preparation of microbial-carrier complex: Functional microbial agents and partially or completely organically modified kaolin carriers were mixed at 132.5 r / min for 35 minutes under the conditions of 23.75℃, protection from light, and 55% relative humidity, and allowed to stand for adsorption for 1.75 hours. During this period, the mixture was stirred for 5 minutes every 30 minutes to obtain an active composite carrier loaded with microorganisms. It is understood that the embodiments of this application employ mild conditions of room temperature and protection from light, coupled with a precise temperature of 23.75℃ and relative humidity control of 55%, which can maximize the preservation of the activity of functional microbial agents and avoid the inactivation of bacteria due to extreme environments. By using a rotation speed of 132.5r / min and a stirring parameter of 35 minutes, uniform dispersion of microbial agents and carriers is achieved. Combined with a static adsorption process of intermittent stirring, it is ensured that the agents are fully adsorbed on the surface and between layers of the carrier, improving the loading capacity and uniformity of the loading. At the same time, the adsorption effect of the carrier can form a protective barrier, reducing the damage to microbial activity caused by subsequent processes, providing a guarantee for the survival of microorganisms in fertilizers and the subsequent functional performance (such as growth promotion and disease resistance) after application, and laying a stable foundation for active functions.

[0090] S3. Preparation of basic mixture: Boric acid, trace element complex and active composite carrier obtained in step S2 are put into a double helix conical mixer, the mixer speed is controlled at 35 r / min, and the mixture is uniformly mixed for 26.25 minutes. It is understood that the use of a double-helix conical mixer in this embodiment, with a rotation speed of 35 r / min and a mixing time of 26.25 minutes, can achieve efficient and uniform mixing of boric acid, trace element complex and active composite carrier, avoiding fertilizer efficacy deviation caused by local component concentration imbalance; this step allows the core nutrients (boric acid, trace elements) and the carrier loaded with microorganisms to form a synergistic system in advance, ensuring the precise and stable ratio of nutrients and functional microorganisms, laying a uniform material foundation for subsequent fusion with liquid synergists and binders, effectively ensuring the consistent distribution of each functional component in the finished fertilizer, and improving the stability and reliability of the overall fertilizer efficacy.

[0091] S4. Preparation of liquid synergist: Humic acid, amino acids, polyglutamic acid and brassinolide are dissolved or dispersed in water, stirred at 36.25℃ and 425r / min for 35 minutes, and the pH of the solution is adjusted to 7.0 to prepare a uniform liquid synergist. It is understood that, in the embodiments of this application, the temperature of 36.25℃ and the high-speed stirring parameters of 425r / min can promote the full dissolution or uniform dispersion of synergistic ingredients such as humic acid and amino acids in water, avoiding uneven synergistic effects caused by insufficient dissolution; adjusting the pH value to a suitable range of 7.0 can ensure the activity and stability of each synergistic ingredient, preventing the degradation and failure of the ingredients due to excessive acidity or alkalinity; the prepared uniform liquid synergist not only facilitates precise integration with the base mixture, but also ensures that the synergistic ingredients (such as promoting nutrient absorption and improving crop stress resistance) are evenly distributed in the finished fertilizer, providing stable support for improving fertilizer utilization and comprehensive efficacy.

[0092] S5. Granulation and molding: The basic mixture from step S3, the remaining carrier, the liquid synergist from step S4, and the aqueous solution of the binder are placed together in a granulator. The granulator speed is controlled at 52.5 r / min, the material temperature at 36.25℃, and the granulator tilt angle at 45° for mixing and granulation.

[0093] It is understood that, in the embodiments of this application, by controlling the granulator speed of 52.5 r / min, the material temperature of 36.25℃, and the tilt angle of 45°, the basic mixture, the remaining carrier, the liquid synergist, and the binder aqueous solution can be fully integrated to form granules with uniform particle size and suitable strength. The addition of the binder ensures stable granule formation and avoids breakage and pulverization during subsequent drying and transportation. The remaining carrier can further adjust the physicochemical properties of the granules and enhance their carrying and protection capabilities for various functional components. The mild temperature of 36.25℃ can avoid high temperature damage to microbial activity and the efficacy of synergistic components. At the same time, the regular granule shape optimizes the convenience of field application (reducing dust and facilitating quantitative spreading), laying the foundation for subsequent drying and product standardization.

[0094] S6. Low-temperature drying and post-treatment: The wet granules obtained from granulation are dried under hot air or vacuum conditions at 55℃, and the final moisture content of the granules is controlled to be less than 5%. After sieving, the boric acid fertilizer product is obtained.

[0095] It is understood that the low-temperature drying condition of 55℃ used in this embodiment can effectively avoid the damage of high temperature to the activity of functional microorganisms, the efficacy of synergistic ingredients, and the stability of nutrients such as boric acid in the fertilizer, ensuring that the core functions of the fertilizer are not lost; controlling the moisture content to below 5% can inhibit the reproduction of harmful microorganisms such as mold and miscellaneous bacteria, prevent the granules from absorbing moisture and clumping, deteriorating and becoming ineffective during storage and transportation, and significantly extend the shelf life of the product; the subsequent screening step can remove unqualified granules, ensure the particle size uniformity of the finished fertilizer, improve the product standardization, and at the same time, the dried granules have stable physical morphology and good flowability, which is convenient for packaging, handling and uniform application in the field, reducing application loss and ensuring the consistency of fertilizer application effect.

[0096] This application also proposes the application of boric acid fertilizer in improving boron nutrient deficiency in crops in acidic or calcareous soils, and in enhancing crop pollen viability and fruit set rate.

[0097] Example 5 This application provides a boric acid fertilizer to increase crop yield, the fertilizer comprising the following weight proportions: Boric acid: 30 parts; Modified synergist: 25 parts; Carrier: 35 copies; Trace element complex: 10 parts; Adhesive: 8 parts.

[0098] The modified synergist comprises the following parts by weight: Humic acid: 12 parts; Amino acids: 12 parts; Brassinolide: 0.5 parts; Polyglutamic acid: 4 parts; Functional microbial inoculant: 5 parts.

[0099] Among them, the functional microbial agent is a potassium-solubilizing agent, which contains Bacillus mucilaginosus and / or silicate bacteria, with an effective viable count of not less than 2.0 × 10⁻⁶. 9 CFU / g.

[0100] Among them, the weight-average molecular weight of polyglutamic acid is 200,000 to 1,000,000 Daltons; the combined mass fraction of proline and glutamic acid in the amino acids is not less than 30% of the total mass of the amino acids.

[0101] The carrier is composed of organically modified kaolin and porous silica in a mass ratio of 1:1, and the specific surface area of ​​the porous silica is not less than 300 m² / g.

[0102] The organically modified kaolin is obtained by modifying kaolin through a cetyltrimethylammonium bromide reaction, wherein the amount of cetyltrimethylammonium bromide added is 2.0 times the cation exchange capacity of kaolin.

[0103] The trace element complex contains zinc and molybdenum, and the zinc and molybdenum are in amino acid chelate form or sugar alcohol complex form.

[0104] The binder is selected from one or more of sodium carboxymethyl cellulose, polyvinyl alcohol, and soluble starch.

[0105] This application also proposes a method for preparing boric acid fertilizer to increase crop yield, comprising the following steps: S1. Preparation of organically modified kaolin: Kaolin was mixed with an aqueous solution of hexadecyltrimethylammonium bromide (CTAB) and stirred at 90°C for 12 hours. After the reaction was completed, the mixture was centrifuged, washed, dried and pulverized to obtain an organically modified kaolin carrier with an interlayer spacing of 1.40 nm. Understandably, this embodiment of the application ensures that CTAB can be fully inserted into the interlayer of kaolin to achieve organic modification by controlling the reaction temperature of 90°C and the reaction time of 12 hours, successfully expanding the interlayer spacing to 1.40 nm, significantly improving the specific surface area and adsorption performance of the carrier; the subsequent centrifugation and washing can remove unreacted CTAB and impurities, ensuring the purity of the carrier, while drying and pulverizing optimize the particle size distribution of the carrier, which can not only provide sufficient adsorption sites for subsequent microbial loading, but also enhance the compatibility between the carrier and organic fertilizer components, avoid component separation during subsequent compounding, lay a high-quality carrier foundation for building a stable fertilizer functional system, and ensure that each functional component can be stably attached.

[0106] S2. Preparation of microbial-carrier complex: Functional microbial agents and partially or completely organically modified kaolin carriers are mixed at 150 r / min for 40 minutes under the conditions of 25℃, light protection, and 60% relative humidity, and allowed to stand for adsorption for 2 hours. During this period, the mixture is stirred for 5 minutes every 30 minutes to obtain an active composite carrier loaded with microorganisms. It is understood that the mild conditions of room temperature and light avoidance used in the embodiments of this application, combined with a precise temperature of 25°C and a relative humidity control of 60%, can maximize the preservation of the activity of functional microbial agents and avoid the inactivation of bacteria caused by extreme environments. By using a rotation speed of 150 r / min and a stirring parameter of 40 minutes, uniform dispersion of microbial agents and carriers is achieved. Combined with the static adsorption process of intermittent stirring, it is ensured that the agents are fully adsorbed on the surface and between layers of the carrier, improving the loading capacity and uniformity of the loading. At the same time, the adsorption effect of the carrier can form a protective barrier, reducing the damage to microbial activity caused by subsequent processes, providing a guarantee for the survival of microorganisms in fertilizers and the subsequent functional performance (such as growth promotion and disease resistance) after application, and laying a stable foundation for active functions.

[0107] S3. Preparation of basic mixture: Boric acid, trace element complex and active composite carrier obtained in step S2 are put into a double helix conical mixer, and the mixer speed is controlled at 40 r / min, and the mixture is mixed evenly for 30 minutes. It is understood that the use of a double-helix conical mixer in this embodiment, combined with a rotation speed of 40 r / min and a mixing time of 30 minutes, can achieve efficient and uniform mixing of boric acid, trace element complex and active composite carrier, avoiding fertilizer efficacy deviation caused by local component concentration imbalance; this step allows the core nutrients (boric acid, trace elements) and the carrier loaded with microorganisms to form a synergistic system in advance, ensuring the precise and stable ratio of nutrients and functional microorganisms, laying a uniform material foundation for subsequent fusion with liquid synergists and binders, effectively ensuring the consistent distribution of each functional component in the finished fertilizer, and improving the stability and reliability of the overall fertilizer efficacy.

[0108] S4. Preparation of liquid synergist: Humic acid, amino acids, polyglutamic acid and brassinolide are dissolved or dispersed in water, stirred at 40℃ and 500r / min for 40 minutes, and the pH of the solution is adjusted to 7.5 to prepare a uniform liquid synergist. It is understood that, in the embodiments of this application, the use of a temperature of 40°C and a high-speed stirring parameter of 500 r / min can promote the full dissolution or uniform dispersion of synergistic components such as humic acid and amino acids in water, avoiding uneven synergistic effects due to insufficient dissolution; adjusting the pH value to a suitable range of 7.5 can ensure the activity and stability of each synergistic component, preventing degradation and failure of components due to excessive acidity or alkalinity; the prepared uniform liquid synergist not only facilitates precise integration with the base mixture, but also ensures that the synergistic components (such as promoting nutrient absorption and enhancing crop stress resistance) are evenly distributed in the finished fertilizer, providing stable support for improving fertilizer utilization and comprehensive efficacy.

[0109] S5. Granulation and molding: The basic mixture from step S3, the remaining carrier, the liquid synergist from step S4, and the aqueous solution of the binder are placed together in a granulator. The granulator speed is controlled at 60 r / min, the material temperature at 40℃, and the granulator tilt angle at 50° for mixing and granulation.

[0110] It is understood that, in the embodiments of this application, by controlling the granulator speed of 60 r / min, the material temperature of 40°C, and the tilt angle of 50°, the basic mixture, the remaining carrier, the liquid synergist, and the binder aqueous solution can be fully integrated to form granules with uniform particle size and suitable strength. The addition of the binder ensures stable granule formation and avoids breakage and pulverization during subsequent drying and transportation. The remaining carrier can further adjust the physicochemical properties of the granules and enhance their carrying and protection capabilities for various functional components. The mild temperature of 40°C can avoid high temperature damage to microbial activity and the efficacy of synergistic components. At the same time, the regular granule shape optimizes the convenience of field application (reducing dust and facilitating quantitative spreading), laying the foundation for subsequent drying and product standardization.

[0111] S6. Low-temperature drying and post-treatment: The wet granules obtained from granulation are dried under hot air or vacuum conditions at 60℃, and the final moisture content of the granules is controlled to be less than 5%. After sieving, the boric acid fertilizer product is obtained.

[0112] It is understood that the low-temperature drying condition of 60℃ used in this embodiment can effectively avoid the damage of high temperature to the activity of functional microorganisms, the efficacy of synergistic ingredients, and the stability of nutrients such as boric acid in the fertilizer, ensuring that the core functions of the fertilizer are not lost; controlling the moisture content to below 5% can inhibit the growth of harmful microorganisms such as mold and miscellaneous bacteria, prevent the granules from absorbing moisture and clumping, deteriorating and becoming ineffective during storage and transportation, and significantly extend the shelf life of the product; the subsequent screening step can remove unqualified granules, ensure the particle size uniformity of the finished fertilizer, improve the product standardization, and at the same time, the dried granules have stable physical morphology and good flowability, which is convenient for packaging, handling and uniform application in the field, reducing application loss and ensuring the consistency of fertilizer application effect.

[0113] This application also proposes the application of boric acid fertilizer in improving boron nutrient deficiency in crops in acidic or calcareous soils, and in enhancing crop pollen viability and fruit set rate.

[0114] The preparation method of this embodiment is the same as that of Embodiment 1.

[0115] Comparative Example 1 This comparative example provides a method for preparing boric acid fertilizer to improve crop yield, which mainly includes the following preparation steps: (1) Preparation of unmodified carrier: ordinary kaolin and porous silica are directly mixed at a mass ratio of 1:0.5, wherein the specific surface area of ​​porous silica is 250m² / g. After uniform mixing, it is used directly as a carrier for later use. (2) Preparation of basic mixture: 18 parts of boric acid, 7 parts of inorganic zinc-molybdenum mixture (zinc sulfate and ammonium molybdate are mixed at a mass ratio of 1:1) and all the carriers prepared in step (1) are put into a double helix conical mixer, and the mixer speed is controlled at 30 r / min and mixed evenly for 20 minutes. (3) Preparation of simplified synergist: Dissolve 8 parts of humic acid and 7 parts of common amino acids (proline and glutamic acid total mass fraction 20%) in water, stir at 30℃ and 300r / min for 30 minutes, adjust the pH of the solution to 6.5, and prepare liquid synergist (excluding brassinolide, polyglutamic acid and functional microbial agents). (4) Granulation and molding: The basic mixture from step (2), the liquid synergist from step (3), and 5 parts of soluble starch aqueous solution are placed together in a granulator. The granulator speed is controlled at 45 r / min, the material temperature at 32℃, and the granulator tilt angle at 40° for mixing and granulation. (5) Drying and post-treatment: The wet granules obtained by granulation are placed under hot air at 70°C for drying, and the final moisture content of the granules is controlled to be less than 5%. After sieving, the boric acid fertilizer product is obtained.

[0116] Comparative Example 2 This comparative example provides a method for preparing boric acid fertilizer to improve crop yield, which mainly includes the following preparation steps: (1) Preparation of modified kaolin: Kaolin was mixed with an aqueous solution of hexadecyltrimethylammonium bromide (CTAB), wherein the amount of CTAB added was 0.5 times the cation exchange capacity of kaolin. The mixture was stirred at 60°C for 3 hours. After the reaction was completed, the mixture was centrifuged, washed, dried and pulverized to obtain an organic modified kaolin carrier. (2) Preparation of microbial-carrier complex: ordinary Bacillus inoculum (effective viable count 1.0 × 10⁻⁶) 9 CFU / g) was uniformly mixed with all organic modified kaolin carriers under normal temperature and natural light conditions. The mixture was stirred at 120 r / min for 30 minutes at 28℃ and 70% relative humidity, and allowed to stand for adsorption for 1.5 hours. During this period, the mixture was stirred for 5 minutes every 30 minutes to obtain an active composite carrier loaded with microorganisms. (3) Preparation of basic mixture: 22 parts of boric acid, 8 parts of amino acid chelated zinc-molybdenum complex and the active composite carrier obtained in step (2) are put into a double helix conical mixer, the mixer speed is controlled at 25 r / min, and the mixture is uniformly mixed for 25 minutes; (4) Preparation of liquid synergist: Dissolve 10 parts of humic acid, 9 parts of amino acids (proline and glutamic acid total mass fraction 35%), 1 part of low molecular weight polyglutamic acid (weight average molecular weight 50,000 Daltons) and 0.3 parts of brassinolide in water, stir at 35°C and 400 r / min for 35 minutes, adjust the pH of the solution to 6.0, and prepare a uniform liquid synergist; (5) Granulation and molding: The basic mixture from step (3), the liquid synergist from step (4), and 4 parts of sodium carboxymethyl cellulose aqueous solution are placed together in a granulator. The granulator speed is controlled at 50 r / min, the material temperature at 45℃, and the granulator tilt angle at 55° for mixing and granulation. (6) Drying and post-treatment: The wet granules obtained by granulation are placed under hot air at 65°C for drying, and the final moisture content of the granules is controlled to be less than 5%. After sieving, the boric acid fertilizer product is obtained.

[0117] Comparative Example 3 This comparative example provides a method for preparing boric acid fertilizer to improve crop yield, which mainly includes the following preparation steps: (1) Preparation of organic modified kaolin: Kaolin was mixed with an aqueous solution of hexadecyltrimethylammonium bromide (CTAB), wherein the amount of CTAB added was 1.5 times the cation exchange capacity of kaolin. The mixture was stirred at 80°C for 8 hours. After the reaction was completed, the mixture was centrifuged, washed, dried and pulverized to obtain an organic modified kaolin carrier with an interlayer spacing of 1.2 nm. (2) Preparation of basic mixture: 25 parts of boric acid, 6 parts of sugar alcohol complexed zinc molybdenum complex and the organic modified kaolin carrier (without added porous silica) prepared in step (1) are put into a double helix conical mixer, the mixer speed is controlled at 35 r / min, and the mixture is uniformly mixed for 22 minutes; (3) Preparation of liquid synergist: Dissolve 12 parts of humic acid, 11 parts of amino acids (proline and glutamic acid with a total mass fraction of 28%), and 3 parts of polyglutamic acid (weight average molecular weight of 800,000 Daltons) in water, stir at 32°C and 350 r / min for 30 minutes, adjust the pH of the solution to 7.0, and prepare a liquid synergist (excluding brassinolide and functional microbial agents). (4) Granulation and molding: The basic mixture from step (2), the liquid synergist from step (3), and 6 parts of polyvinyl alcohol aqueous solution are placed together in a granulator. The granulator speed is controlled at 35 r / min, the material temperature at 22℃, and the granulator tilt angle at 25° for mixing and granulation. (5) Drying and post-treatment: The wet granules obtained by granulation are placed under vacuum at 35°C for drying, and the final moisture content of the granules is controlled to be less than 5%. After sieving, the boric acid fertilizer product is obtained.

[0118] Performance testing The long-term fertilization capacity and microbial survival stability of the boric acid fertilizers prepared in Examples 1-5 and Comparative Examples 1-3 were analyzed using the soil culture method. Forty-eight samples each of acidic soil (pH 5.0) and calcareous soil (pH 8.2) were selected, with each sample weighing 2 kg. They were randomly divided into 8 groups (Example 1-5 groups and Comparative Examples 1-3 groups), with 6 samples in each group (3 samples of acidic soil and 3 samples of calcareous soil). Equal amounts (2 g / kg soil) of the corresponding fertilizer were applied to each sample, and they were placed in a constant temperature and humidity incubator to simulate the natural environment (temperature 25℃, relative humidity 60%) for 60 days. The effective boron release, available potassium content, and viable number of functional microorganisms in the soil were measured at 10, 30, and 60 days of culture. The performance test data are shown in Table 1.

[0119] Table 1. Results of tests on fertilizer long-term fertilization capacity and microbial survival stability.

[0120] As shown in Table 1, the boric acid fertilizers prepared in Examples 1-5 of this application exhibit excellent performance in terms of long-term fertilization capacity and microbial survival stability. The effective boron release after 60 days reaches 42.6-43.6 mg / kg, the available potassium content reaches 185.3-193.4 mg / kg, and the retention rate of viable functional microorganisms is all above 90% (initial viable count ≥ 2.0 × 10⁻⁶). 9The CFU / g ratio of the samples was significantly better than that of Comparative Examples 1-3. In the examples, the stable framework constructed from the organically modified kaolin and porous silica composite carrier enabled the slow release of nutrients and effective protection of microorganisms. Combined with the high activity of the functional potassium-solubilizing agent, it continuously activated soil potassium. In contrast, the comparative examples suffered from significant declines in effectiveness due to carrier defects or missing components: Comparative Example 1 used an unmodified carrier with a small specific surface area and poor adsorption performance, resulting in an effective boron release of only 32.1 mg / kg. Furthermore, without the addition of functional microbial agents, the available potassium content was only 145.2 mg / kg. Comparative Example 2 had low initial activity of the microbial agent and lacked light protection during preparation, resulting in a viable bacterial count of only 0.92 × 10⁻⁶ after 60 days. 9 The CFU / g limit restricts nutrient activation capacity; Comparative Example 3 lacks brassinolide and functional microbial agents, failing to achieve synergistic nutrient release, with a readily available potassium content of only 162.3 mg / kg, fully demonstrating the key impact of the synergistic effect of the composite modified carrier and functional components on long-term fertilization capacity.

[0121] The crop growth-enhancing effects of boric acid fertilizers prepared in Examples 1-5 and Comparative Examples 1-3 were analyzed using field trials. Tomatoes grown in acidic soil and wheat grown in calcareous soil were selected as experimental crops. Eight experimental plots were set up for each crop (Examples 1-5 and Comparative Examples 1-3), each plot covering 20 m², randomly arranged and replicated three times. 20 kg per mu (approximately 0.067 hectares) was applied as basal fertilizer, with other field management conditions remaining consistent. Pollen viability was measured during the flowering stage of tomatoes, and fruit set rate and yield per mu were calculated at maturity. Pollen viability was measured during the flowering stage of wheat, and fruit set rate and yield per mu were calculated at maturity. Performance test data are shown in Table 2.

[0122] Table 2. Test results of crop pollen viability, fruit setting rate (seed set rate), and yield improvement.

[0123] As shown in Table 2, the boric acid fertilizers prepared in Examples 1-5 of this application have significant effects on improving crop pollen vitality, fruit setting rate (fruit set rate) and yield. Tomato pollen vitality reached 92.3%-92.9%, fruit setting rate reached 89.5%-90.5%, and yield increase rate per mu reached 30.2%-31.2%. Wheat pollen vitality reached 91.8%-92.5%, fruit set rate reached 88.6%-89.5%, and yield increase rate per mu reached 28.5%-29.5%. All indicators far exceed those of comparative examples 1-3. In the examples, boric acid can directly supplement boron, and amino acid-chelated zinc and molybdenum are easily absorbed by crops. They work synergistically with brassinolide, polyglutamic acid, and other synergistic components to significantly improve pollen viability and fruit set rate. However, the comparative examples showed poor results due to component or process defects: Comparative Example 1 used an inorganic zinc-molybdenum mixture, which is easily fixed by the soil and lacks brassinolide, polyglutamic acid, and functional microbial agents, resulting in tomato pollen viability of only 75.6% and a yield increase of only 15.8% per mu; Comparative Example 2 used a high-temperature drying process that destroyed microbial activity and some nutrient structure, resulting in a wheat seed setting rate of only 78.8% and a yield increase of only 21.5% per mu; Comparative Example 3 lacked brassinolide and functional microbial agents, failing to form a synergistic nutrient effect, resulting in a tomato fruit set rate of only 82.8%. These examples fully demonstrate the importance of the chelated form of boron and trace elements and the synergistic effect of various functional components for improving crop growth.

[0124] The storage stability and particle physical properties of the boric acid fertilizers prepared in Examples 1-5 and Comparative Examples 1-3 were analyzed using accelerated aging tests and physical property testing methods. Storage stability test: Each fertilizer sample was placed in a constant temperature and humidity chamber at 40℃ and 75% relative humidity for accelerated aging for 3 months, and the retention rate of viable microorganisms and particle breakage rate were detected before and after aging. Particle physical property test: The particle size uniformity (percentage of 1-3mm particles), compressive strength and dust rate during application of fresh samples were detected. The performance test data are shown in Table 3.

[0125] Table 3. Results of fertilizer storage stability and particle physical properties tests

[0126] As shown in Table 3, the boric acid fertilizers prepared in Examples 1-5 of this application have excellent storage stability and good particle physical properties. After accelerated aging for 3 months, the retention rate of viable microorganisms reached 88.5%-90.2%, the particle breakage rate was only 2.7%-3.2%, the particle size uniformity (1-3mm percentage) of fresh samples reached 92.6%-93.8%, the particle compressive strength reached 18.6-20.3N, and the application dust rate was only 0.9%-1.2%. All indicators are significantly better than those of comparative examples 1-3. The examples used environmentally friendly and efficient binders. By precisely controlling the granulator speed, material temperature, and tilt angle, granules with uniform size and suitable strength were prepared. Combined with a low-temperature drying process of 40-60℃, the damage to microbial activity caused by high temperature was effectively avoided, improving storage stability. In contrast, the comparative examples suffered from insufficient performance due to process or component defects: Comparative Example 1 used high-temperature drying at 70℃ and did not add functional microbial agents, resulting in a granule compressive strength of only 12.5N, a breakage rate of 8.6% after aging, and an application dust rate as high as 3.8%; Comparative Example 2 had an excessively high granulation temperature (45℃) and an excessively large tilt angle (55°), resulting in a particle size uniformity of only 85.6%, and the high-temperature drying also resulted in a microbial viable count retention rate of only 65.3%; Comparative Example 3 had a single carrier and an excessively low granulation temperature (22℃), resulting in insufficient granule strength (13.6N), and a breakage rate of 6.5% after aging. These examples fully verified the key role of reasonable binder selection, precise granulation process, and low-temperature drying in the storage stability and physical properties of fertilizers.

[0127] In summary, this application's embodiments, through the construction of a stable framework using organically modified kaolin and porous silica composite carriers, the synergistic effect of functional components, and precise process control, prepared a high-performance boric acid fertilizer. This fertilizer exhibited excellent long-term fertilization and microbial survival stability in 60-day incubation tests on acidic and calcareous soils (effective boron release 42.6-43.6 mg / kg, available potassium 185.3-193.4 mg / kg, and viable count of functional microorganisms 1.82-1.90 × 10⁻⁶). 9 CFU / g, retention rate ≥90%; significantly improved crop growth performance in field trials (tomato pollen viability 92.3%-92.9%, fruit setting rate 89.5%-90.5%, yield increase 30.2%-31.2% per mu, wheat pollen viability 91.8%-92.5%); maintained excellent storage stability and physical properties even after 3 months of accelerated aging (microbial viable count retention rate 88.5%-90.2%, particle breakage rate 2.7%-3.2%, fresh sample particle size uniformity 92.6%-93.8%, compressive strength 18.6-20.3 N), all indicators were significantly better than the comparative examples (e.g., Comparative Example 1 had 32.1 mg / kg available boron and 145.2 mg / kg available potassium; Comparative Example 2 had 0.92 × 10⁻⁶ viable bacteria count after 60 days). 9CFU / g; Comparative Example 3: Available potassium 162.3 mg / kg). The comparative examples suffered from a significant decline in efficacy due to carrier defects (unmodified, single carrier), missing components (functional microorganisms, brassinolide), or improper processes (high-temperature drying, unsuitable granulation parameters), resulting in loss of synergistic effects or destruction of activity. In contrast, the compound carrier of this application achieves slow release of nutrients and protection of microorganisms, synergistic activation of nutrients by functional components, and precise processing to ensure the retention of granule performance and activity, thereby enhancing the application value of boric acid fertilizer in crop cultivation.

[0128] According to the embodiments of this application, a boric acid fertilizer for improving crop yield and its preparation method are proposed. A stable carrier framework is constructed by compounding organically modified kaolin (CTAB ion exchange modified, precisely matching cation exchange capacity, interlayer spacing 1.05-1.40 nm) with porous silica (specific surface area ≥300 m² / g). This framework is then combined with humic acid, amino acids (proline + glutamic acid ≥30%), brassinolide, polyglutamic acid (weight average molecular weight 200,000-1,000,000 Daltons), and a functional potassium-solubilizing bacteria agent (effective viable count ≥2.0 × 10⁻⁶). 9 CFU / g) and amino acid chelated / sugar alcohol complexed zinc and molybdenum, combined with boric acid for direct boron supplementation, achieve nutrient binding, microbial colonization protection, and synergistic fertilization (60-day effective boron release 42.6-43.6 mg / kg, available potassium 185.3-193.4 mg / kg, improving crop pollen viability by 91.8%-92.9%, and fruit setting rate by 89.5%-90.5%); using environmentally friendly binders such as sodium carboxymethyl cellulose, and precisely controlling granulation parameters (rotation speed 30-60 r / min, material temperature 25-40℃, tilt angle 30-50°) and low-temperature drying at 40-60℃ (moisture content <5%), uniform particle size and suitable strength particles are prepared (uniformity 92.6%-93.8%, compressive strength 18.6-20.3 N), and accelerated aging for 3 months. The monthly microbial viable count retention rate is 88.5%-90.2%, and the particle breakage rate is 2.7%-3.2%, improving storage stability and reducing dust pollution and breakage losses. Through precise control of modification (70-90℃, 4-12h), microbial-carrier composite (room temperature, protected from light), and synergist preparation (pH 5.5-7.5), the activity of components and batch consistency of products are ensured, and the environmentally friendly materials and reasonable processes do not cause soil pollution. By integrating the above-mentioned component synergy and process control, precise control of long-term fertilizer supply, stable microbial survival, improved crop growth, safe storage, and environmentally friendly production is achieved. This breaks through the technical bottlenecks of traditional boric acid fertilizers, such as poor carrier adsorption, rapid nutrient loss, low microbial activity, and insufficient product stability, and enhances the application value of boric acid fertilizers in the planting of crops in different types of soil.

[0129] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

[0130] The present application and its embodiments have been described above. This description is not restrictive, and the actual application is not limited thereto. In conclusion, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the spirit of this application, such design should fall within the protection scope of this application.

Claims

1. A boric acid fertilizer for increasing crop yield, characterized in that, The fertilizer comprises the following parts by weight: Boric acid: 10-30 parts; Modified synergist: 15-25 parts; Carrier: 20-35 copies; Trace element complex: 5-10 parts; Adhesive: 3-8 parts.

2. The boric acid fertilizer for increasing crop yield according to claim 1, characterized in that, The modified synergist comprises the following parts by weight: Humic acid: 8-12 parts; Amino acids: 7-12 parts; Brassinolide: 0.1-0.5 parts; Polyglutamic acid: 2-4 parts; Functional microbial inoculant: 0.5-5 parts.

3. The boric acid fertilizer for increasing crop yield according to claim 2, characterized in that, The functional microbial agent is a potassium-solubilizing agent, which contains Bacillus mucilaginosus and / or silicate bacteria, with an effective viable count of not less than 2.0 × 10⁻⁶. 9 CFU / g.

4. The boric acid fertilizer for increasing crop yield according to claim 2, characterized in that, The polyglutamic acid has a weight-average molecular weight of 200,000 to 1,000,000 Daltons; the combined mass fraction of proline and glutamic acid in the amino acid is not less than 30% of the total mass of the amino acid.

5. The boric acid fertilizer for increasing crop yield according to claim 1, characterized in that, The carrier is composed of organically modified kaolin and porous silica in a mass ratio of 1:(0.2-1), and the specific surface area of ​​the porous silica is not less than 300 m² / g.

6. The boric acid fertilizer for increasing crop yield according to claim 5, characterized in that, The organically modified kaolin is obtained by modifying kaolin through a cetyltrimethylammonium bromide reaction, wherein the amount of cetyltrimethylammonium bromide added is 0.8 to 2.0 times the cation exchange capacity of the kaolin.

7. The boric acid fertilizer for increasing crop yield according to claim 1, characterized in that, The trace element complex contains zinc and molybdenum, and the zinc and molybdenum are in an amino acid chelate state or a sugar alcohol complex state.

8. The boric acid fertilizer for increasing crop yield according to claim 1, characterized in that, The binder is selected from one or more of sodium carboxymethyl cellulose, polyvinyl alcohol, and soluble starch.

9. A method for preparing boric acid fertilizer for increasing crop yield as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Preparation of organically modified kaolin: Kaolin is mixed with an aqueous solution of hexadecyltrimethylammonium bromide (CTAB) and stirred at 70-90℃ for 4-12 hours. After the reaction is completed, the mixture is centrifuged, washed, dried and pulverized to obtain an organically modified kaolin carrier with an interlayer spacing of 1.05-1.40 nm. S2. Preparation of microbial-carrier complex: The functional microbial agent and part or all of the organic modified kaolin carrier are stirred and mixed at 80-150 r / min for 20-40 minutes under the conditions of 20-25℃, in the dark, and relative humidity of 40%-60%, and allowed to stand for adsorption for 1-2 hours, with stirring for 5 minutes every 30 minutes during the process, to obtain an active composite carrier loaded with microorganisms. S3. Preparation of basic mixture: The boric acid, trace element complex and the active composite carrier obtained in step S2 are put into a double helix conical mixer, and the mixer speed is controlled at 20-40 r / min. Mix evenly for 15-30 minutes. S4. Preparation of liquid synergist: Dissolve or disperse the humic acid, amino acids, polyglutamic acid and brassinolide in water, stir at 25-40℃ and 200-500 r / min for 20-40 minutes, adjust the pH of the solution to 5.5-7.5, and prepare a uniform liquid synergist; S5. Granulation and molding: The basic mixture from step S3, the remaining carrier, the liquid synergist from step S4, and the aqueous solution of the binder are placed together in a granulator. The granulator speed is controlled at 30-60 r / min, the material temperature at 25-40℃, and the granulator tilt angle at 30-50° for mixing and granulation. S6. Low-temperature drying and post-treatment: The wet granules obtained by granulation are dried under hot air or vacuum conditions at 40-60℃, and the final moisture content of the granules is controlled to be less than 5%. After sieving, the boric acid fertilizer product is obtained.

10. The application of a boric acid fertilizer as described in any one of claims 1-8 in improving boron nutrient deficiency in crops, enhancing pollen viability and fruit setting rate in acidic or calcareous soils.

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