Banana fruit cracking prevention planting method

Abstract

The invention discloses a banana fruit cracking prevention planting method which comprises the following steps: 1) applying a decomposed organic fertilizer into a field, performing rotary tillage, furrowing, planting banana seedlings, applying an amino acid liquid fertilizer once every 15-20 days, applying a humic acid liquid fertilizer once every 10-15 days, applying trace elements when bananas are about to bud, and continuously planting until the bananas bud; 2) applying a root fertilizer once every 5-6 days and a root protection fertilizer once every 15 days in a budding stage, thinning flowers after flower buds grow out, and thinning fruits and vegetables according to plant growth vigor and nutritional conditions in the initial development stage of banana fruits; the method comprises the following steps of (1) planting bananas, (2) planting the bananas, (3) applying a calcium-rich compound fertilizer once every 10-15 days when young bananas comb upwards, and continuously planting the bananas until the bananas are harvested, and (4) harvesting the bananas timely according to the maturity of the bananas and the market demand, and keeping the soil humidity between 60% and 80% in the whole planting period, so that the fruit cracking phenomenon can be reduced, and the quality and the yield of the bananas are improved.

Description

Technical Field

[0001] The present invention relates to the field of banana planting, and more particularly to a method for planting bananas to prevent cracking of bananas. Background Art

[0002] Fruit cracking is a common and thorny problem in banana cultivation. Banana fruit cracking not only reduces the commercial value of the fruit, but may also cause the fruit to rot, reduce yield, and bring economic losses to growers.

[0003] The reasons for banana fruit cracking are relatively complex. On the one hand, bananas have special and diverse requirements for nutrients during their growth. Traditional planting methods lack scientific planning in the selection and application of fertilizers. For example, if sufficient nutrients such as amino acids and humic acid are not supplemented in time in the early stage of banana growth, it will affect the basic growth and nutrient reserves of the plant, resulting in poor fruit development in the later stage and increasing the risk of fruit cracking. The lack or imbalance of trace elements can also seriously affect the growth of bananas. For example, boron plays an important role in the stability of banana cell walls, zinc participates in a variety of enzymatic reactions of plants, and iron, manganese, molybdenum and other elements are indispensable in banana photosynthesis, respiration and other physiological processes. If these trace elements are insufficient in the soil, or if they are not effectively supplemented during the critical period of banana growth, the fruit cell wall strength is not enough, and it is easy to crack during the fruit expansion process due to the inability to withstand internal pressure. On the other hand, at different growth stages of bananas, such as budding stage and fruit development stage, different requirements for fertilizer types and fertilization frequency are required. In traditional planting, fertilization during the budding period is unscientific, and root fertilizer and root protection fertilizer are not applied reasonably according to the growth characteristics of bananas, resulting in poor development of the plant root system, affecting nutrient absorption and transmission, and causing abnormal fruit growth. In the early stages of fruit development, unreasonable flower and fruit thinning, retaining too many fruits, will cause competition for nutrients between fruits, and the fruits will grow in different sizes, which is also prone to fruit cracking. In addition, soil moisture management is also crucial. If the soil moisture fluctuates too much or is in an unsuitable range for a long time, it will affect the banana plant's absorption of water and nutrients, thereby affecting the normal development of the fruit and causing frequent fruit cracking. When solving these problems, since banana growth involves multiple complex physiological processes and many influencing factors, it is difficult to find a comprehensive and effective comprehensive solution, and often one thing is lost while another is taken care of, and the problem of banana fruit cracking cannot be fundamentally solved. Summary of the invention

[0004] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0005] Another object of the present invention is to provide a method for planting bananas to prevent fruit cracking, which provides a suitable environment and sufficient nutrients for banana growth through scientific planting steps and reasonable fertilizer application, as well as precise control of soil moisture, thereby ensuring normal fruit development, reducing fruit cracking, and improving the quality and yield of bananas.

[0006] In order to achieve these purposes and other advantages according to the present invention, a method for planting banana crack-proof fruits is provided, comprising the following steps: Step 1: Apply decomposed organic fertilizer to the field, till the soil and make ridges, plant banana seedlings, apply amino acid liquid fertilizer every 15-20 days, apply humic acid liquid fertilizer every 10-15 days, and apply trace elements when the bananas are about to bud, and continue planting until the bananas bud; Step 2: During the budding period, apply root fertilizer every 5-6 days and root mulch fertilizer every 15 days. After the buds are drawn, when the inflorescence opens to the 5th to 8th female flowers, use a knife to remove the buds of neutral and male flowers and retain healthy female flowers. In the early stage of banana fruit development, according to the growth and nutritional status of the plant, each banana plant should retain 6-8 bunches of fruits, and each bunch of fruits should retain 14-16 fruit fingers; Step 3: When the banana fruit is combed upward, apply compound fertilizer rich in calcium every 10-15 days, with an application rate of 10-15 kg per mu, and continue planting until harvest; Step 4: Harvest bananas in a timely manner according to the maturity of bananas and market demand; During the entire planting period, soil moisture is maintained between 60-80%.

[0007] The present invention applies different fertilizers at different growth stages of bananas to provide a comprehensive and continuous nutrient supply. In the early stage, amino acid and humic acid liquid fertilizers are applied to promote plant growth and nutrient accumulation; in the budding stage, reasonable fertilization and flower and fruit thinning are applied to ensure that the fruit growth has sufficient nutrients and is evenly distributed; in the young fruit stage, calcium fertilizer and compound fertilizer are applied to enhance the strength of the fruit cell wall. The soil moisture is accurately controlled to create a stable environment for banana growth. Through these measures, the fruit cracking phenomenon is effectively reduced, the fruit quality and yield are improved, and the economic benefits of growers are increased.

[0008] Preferably, the trace elements include boron, zinc, iron, manganese and molybdenum, and 100 parts of boron, 150 parts of zinc, 200 parts of iron, 100 parts of manganese and 10 parts of molybdenum are applied per mu of land.

[0009] The present invention can accurately meet the needs of banana growth for elements such as boron, zinc, iron, manganese, and molybdenum. These elements play an important role in the physiological process of bananas. Boron can enhance the stability of cell walls, zinc participates in enzymatic reactions, and iron, manganese, and molybdenum affect photosynthesis and respiration. Reasonable supplementation of these trace elements helps to improve the stress resistance of banana plants, enhance the strength of fruit cell walls, reduce fruit cracking, and improve banana quality and yield.

[0010] Preferably, the trace elements are compounded with humic acid, and the ratio of the sum of the masses of humic acid and trace elements is 1:10.

[0011] The present invention adopts a composite ratio of 1:10, so that humic acid can fully wrap and complex trace elements. The adsorption and ion exchange properties of humic acid can effectively reduce the fixation and loss of trace elements in the soil, so that the trace elements can be more stably present in the soil, which is convenient for banana root absorption. This not only improves the effectiveness and utilization rate of trace elements, but also can continuously provide the required nutrients for banana growth, ensure the normal development of fruits, reduce fruit cracking, and improve the quality of bananas.

[0012] Preferably, the method for compounding trace elements and humic acid comprises the following steps: Dispersing nano-silica in anhydrous ethanol, ultrasonically treating for 30-60 min to fully disperse it, adding 3-aminopropyltriethoxysilane dropwise thereto, the mass ratio of 3-aminopropyltriethoxysilane to nano-silica being 1:5-1:8, stirring and reacting at 60-80°C for 6-8 h to graft 3-aminopropyltriethoxysilane onto the surface of nano-silica, and after the reaction is completed, centrifuging and washing to obtain surface-modified nano-silica; The surface-modified nano-silica is re-dispersed in deionized water, polyethyleneimine is added, and the mixture is stirred and reacted for 2-3 hours at room temperature to allow the polyethyleneimine to be compounded with the nano-silica through chemical bonding and physical adsorption to form a nano-silica-polyethyleneimine composite carrier; Dissolve the above-mentioned trace element fertilizers in water, stir them thoroughly to make them completely dissolved, and obtain a trace element fertilizer solution; Dissolve humic acid in water according to the ratio, then slowly add the trace element fertilizer solution into the humic acid solution, stirring while adding, and react at room temperature for 1-2 hours to form a preliminary humic acid-trace element complex; The prepared nano-silica-polyethyleneimine composite carrier is added to the humic acid-trace element complex solution, and the reaction is continued by stirring for 3-4 hours. After the reaction is completed, the humic acid-trace element complex is obtained by drying.

[0013] In the soil environment, pH value has a crucial influence on the stability of humic acid-trace element complex. The present invention prepares a composite carrier by subjecting nano-silicon dioxide, 3-aminopropyltriethoxysilane, polyethyleneimine, etc. to a series of reactions, and then composites it with the humic acid-trace element complex. This composite system has a certain acid-base buffering capacity, and can effectively reduce the damage to the humic acid-trace element composite structure caused by changes in pH in soil environments with different pH values.

[0014] Preferably, the root fertilizer includes Litian Funong 30-10-10+TE, Litian Funong 5-5-45+TE and potassium chloride, Litian Funong 30-10-10+TE 11 g / plant, Litian Funong 5-5-45+TE 11 g / plant, and potassium chloride 15 g / plant.

[0015] Litian Funong 30-10-10+TE contains a high proportion of nitrogen, which can promote the growth and photosynthesis of banana plant leaves, make the leaves more luxuriant, and enhance the assimilation capacity of the plant; Litian Funong 5-5-45+TE is rich in high potassium, which plays an important role in making banana stems thicker and enhancing the plant's resistance to lodging, and also helps the fruit to expand and improve its quality; potassium chloride supplements potassium and chlorine, of which potassium participates in many physiological processes of plants, such as enzyme activation and transportation of photosynthesis products, and chlorine also has a certain promoting effect on the growth and development of bananas. The combination of the three provides balanced nutrients for bananas during the budding period, promotes the overall growth of the plant, makes the plant stronger, helps to enhance the resistance of banana plants, and enables them to better cope with changes in the external environment, such as temperature fluctuations, pests and diseases, etc. During the fruit development process, sufficient nutrients can make the fruit cell wall tougher and reduce the cracking of the fruit caused by fruit expansion.

[0016] Preferably, the root protection fertilizer includes 200 parts of biological carbon-based phosphate fertilizer, 20 parts of amino acid calcium, 10 parts of phosphate-dissolving and potassium-dissolving bacteria preparation, 5 parts of arbuscular mycorrhizal fungal spore preparation, 40 parts of seaweed oligosaccharide, 50 parts of humic acid, 30 parts of starch-based slow-release agent and 40 parts of bentonite; wherein the number of viable bacteria of phosphate-dissolving and potassium-dissolving bacteria reaches 3×10 8 - 4×10 8 pcs / portion, arbuscular mycorrhizal fungal spores ≥120 pcs / portion.

[0017] Biocarbon-based phosphate fertilizer and humic acid can effectively improve soil structure, increase soil porosity, and improve soil air permeability and water permeability. At the same time, they can also enhance the soil's ability to absorb nutrients and water, so that the soil can better preserve nutrients in root fertilizer, reduce nutrient loss, provide a stable soil environment for banana growth, and help the root system to better take root and absorb nutrients. Phosphorus and potassium-dissolving bacteria can convert insoluble phosphorus and potassium in the soil into forms that can be absorbed by plants. Arbuscular mycorrhizal fungi can form a symbiotic relationship with banana roots, expand the absorption area of ​​the roots, and enhance the root system's ability to absorb nutrients. This allows the nutrients in root fertilizer and soil to be more fully utilized by bananas, improves fertilizer utilization, reduces fertilizer waste, and reduces planting costs. Amino acid-complexed calcium can provide a stable calcium source for bananas. Calcium plays an important role in strengthening the strength of fruit cell walls, improving fruit hardness and storage resistance, and can effectively reduce fruit cracking. Seaweed oligosaccharides can regulate plant physiological metabolism, enhance plant resistance, and enable bananas to grow better in the face of adversities such as pests and diseases and drought. The various ingredients in the root protection fertilizer can provide a good environment and sufficient nutrients for root growth, stimulate the growth and development of the root system, make the root system more developed, better fix the plant, absorb more water and nutrients, provide strong support for plant growth, enhance the plant's growth vitality, and ensure that bananas can grow healthily throughout the entire growth cycle.

[0018] Preferably, the biocarbon-based phosphate fertilizer is further processed as follows, wherein the specific processing comprises the following steps: Dissolve 2 g of polymethacrylic acid in 100 mL of anhydrous ethanol and stir magnetically for 30-60 min until it is completely dissolved to obtain a uniform polymethacrylic acid solution. Add 0.5 g of nano-silica to 50 mL of anhydrous ethanol and disperse by ultrasonication for 30 min to uniformly disperse the nano-silica in the ethanol solution. Slowly drop the dispersed nano-silica ethanol solution into the polymethacrylic acid solution while stirring. The dropping time is 15-20 min. After the dropping is completed, add 0.05 g of cross-linking agent N, N'-methylenebisacrylamide and continue stirring for 30 min to fully mix. Then transfer the reaction system to a reactor and react at 60-70 ° C for 4-6 hours. During this period, continue stirring to promote the composite reaction of polymethacrylic acid and nano-silica. After the reaction is completed, the reaction solution is cooled to room temperature, centrifuged at a speed of 8000-10000 r / min for 10-15 minutes to precipitate the polymer-silica composite structure, the supernatant is removed, and the precipitate is washed with anhydrous ethanol 3-4 times, and centrifuged again after each washing to remove unreacted raw materials and impurities; The washed precipitate is placed in a vacuum drying oven and dried at 40-50°C for 6-8 hours to obtain a dried polymer-silicon dioxide composite structure product, and the dried product is ground into powder using a mortar to obtain a polymer-silicon dioxide composite powder; Pour the polymer-silica composite powder and the biocarbon-based phosphate fertilizer into a mixing container at a ratio of 1:10, turn on the mixer, set the low-speed stirring to 100-200 r / min, stir for 5-10 min to initially disperse the materials; then adjust to medium speed to about 300-400 r / min, stir for 10-15 min to ensure that the two are fully mixed.

[0019] The present invention uses a polymer-silicon dioxide composite to wrap the biocarbon-based phosphate fertilizer, which can effectively isolate the influence of adverse factors in the soil on the phosphorus element. After surface modification, the nano-silicon dioxide is compounded with polymethacrylic acid to form a stable structure, which protects the phosphorus element from reacting with metal ions such as calcium, iron, and aluminum in the soil to form insoluble salts, reduces the fixation and loss of phosphorus, improves the stability of the fertilizer in the soil, and ensures that more phosphorus elements can be absorbed and utilized by the banana root system.

[0020] Preferably, the preparation of biological carbon-based phosphate fertilizer comprises the following steps: The rice husk biochar was crushed to 100-200 mesh, and potassium dihydrogen phosphate was dissolved in deionized water to prepare a solution with a concentration of 0.5-1.0 mol / L; Add rice husk biochar to potassium dihydrogen phosphate solution, and control the solid-liquid ratio of biochar to solution at 1:5-1:10. Use a magnetic stirrer to stir at 200-300 r / min for 2-3 h at room temperature to allow potassium dihydrogen phosphate to be fully adsorbed on the surface of biochar. Then, transfer the reaction system to a constant temperature water bath and continue stirring the reaction at 50-60°C for 4-6 h. After the reaction is completed, centrifuge at a speed of 8000-10000 r / min for 10-15 min to precipitate the biochar-based phosphate fertilizer, remove the supernatant, place the precipitate in a drying oven, and dry it at 40-50 ℃ for 6-8 hours to obtain dry biochar-based phosphate fertilizer.

[0021] The method of the present invention promotes the formation of a relatively stable binding structure between potassium dihydrogen phosphate and biochar through specific stirring and reaction conditions. Stirring at room temperature allows the potassium dihydrogen phosphate to be initially adsorbed, and stirring in a constant temperature water bath further strengthens the interaction between the two, allowing the phosphorus element to be more firmly bound to the biochar. Subsequent centrifugation and drying treatments remove excess water and unbound substances, making the structure of the biocarbon-based phosphate fertilizer more compact and stable. This stable structure, after being compounded with a polymer-silicon dioxide composite, can better resist the influence of physical, chemical and biological factors in the soil, reduce the loss and fixation of phosphorus, improve the stability of the fertilizer in the soil, and ensure the continuous supply of phosphorus.

[0022] Preferably, the compound fertilizer rich in calcium is made from the following raw material components: 30-30 parts of calcium nitrate, 15-20 parts of potassium dihydrogen phosphate, 10-15 parts of magnesium sulfate, 5-10 parts of chelated trace elements, 5-10 parts of biochar, 1-2 parts of microbial agents and 5-10 parts of chelating agents; The chelating agent is prepared by dissolving polyaspartic acid and amino acid in water at a mass ratio of 2:1 to prepare a solution with a mass ratio of 10% of the chelating agent; Microbial agents include Bacillus subtilis, Bacillus licheniformis and Bacillus amyloliquefaciens.

[0023] Compound fertilizer contains multiple ingredients, such as calcium nitrate for calcium, potassium dihydrogen phosphate and magnesium sulfate for phosphorus, potassium and magnesium respectively. The formula design takes into account the multiple nutrients required for banana growth. By providing comprehensive nutrients, it avoids abnormal absorption of calcium by bananas due to the lack of one or several elements. The chelating agent combines with calcium to change its existing form in the soil solution, reduce the activity of chemical reactions between calcium and other ions, thereby reducing the interference of other ions on calcium absorption, improving the effectiveness of calcium in the soil and the absorption efficiency of bananas, and solving the problem that multiple elements in fertilizers may antagonize in the soil and affect the absorption and utilization of various elements by bananas, so as to meet the nutrient needs of bananas in the young fruit stage and ensure the normal growth of fruits. The microbial agents include Bacillus subtilis, Bacillus licheniformis and Bacillus amyloliquefaciens. These beneficial microorganisms can regulate the soil microecological environment, inhibit the growth of harmful microorganisms, promote the transformation and release of nutrients in the soil, and create a good soil environment for banana growth.

[0024] Preferably, the preparation of the calcium-rich composite fertilizer comprises the following steps: Calcium nitrate, potassium dihydrogen phosphate, magnesium sulfate and chelated trace elements are crushed separately to a particle size of 80-100 mesh; The biochar is crushed and sieved to a particle size of 80-100 mesh; Premix the microbial agent with vermiculite powder; Add the pretreated raw materials into a horizontal mixer according to the formula ratio, and stir them at a low speed of 100-150 r / min for 15-20 min to make the raw materials preliminarily mixed; then add the chelating agent, and then adjust the stirring speed to medium speed, at a speed of 200-300 r / min, for 25-35 min to fully mix; The mixed materials are made into granular compound fertilizer by extrusion granulation process. During the granulation process, the temperature is controlled at 45-60 ℃. After granulation, the fluidized bed dryer is used for low-temperature drying, and the temperature is controlled at 50-60 ℃ to control the moisture content of the compound fertilizer below 5%; The dried compound fertilizer particles are screened, and a blend of polyvinyl alcohol and starch is used to coat the particles to obtain a compound fertilizer rich in calcium.

[0025] The present invention coats the compound fertilizer particles, and uses a blend of polyvinyl alcohol and starch as the coating material. The coating can isolate the fertilizer particles from the soil environment, slowing down the contact speed between the calcium element in the fertilizer and the substances in the soil that may cause precipitation. In the soil, the coating material will gradually degrade, so that the calcium element in the fertilizer is slowly released, reducing the probability that the calcium element combines with carbonate, phosphate, etc. in the soil in a short time to form precipitation.

[0026] Preferably, the preparation method of chelated trace elements comprises the following steps: Dissolve polyaspartic acid in deionized water to prepare a solution with a concentration of 15%-20%, and use an ultrasonic disperser to perform ultrasonic treatment for 15-20 minutes to obtain a polyaspartic acid solution; the polyaspartic acid has a molecular weight of 3000-5000; The amino acid mixture was mixed in a molar ratio of glycine: glutamic acid: lysine = 3:2:1 to prepare a total concentration of 10%-15% amino acid mixed solution, and ultrasonic treatment was also performed for 10-15 min; Ferrous sulfate, zinc sulfate and manganese sulfate are dissolved in deionized water to prepare a metal salt solution with a concentration of 10%-15%, and filtered to remove insoluble impurities; Add the polyaspartic acid solution and the amino acid mixed solution in a volume ratio of 1:1 - 1:1.5 into a container equipped with a stirrer, a thermometer and a reflux condenser, slowly heat up to 60-70 °C under nitrogen protection, control the stirring speed at 200-300 r / min, react for 1-2 h, and end the reaction to obtain a composite chelating agent precursor; The mixed solution is cooled to 30-40°C, and the metal salt solution is slowly added dropwise according to the molar ratio of iron: zinc: manganese = 1:1:1. The addition time is controlled within 30-45 min, and stirring is performed while adding. After the addition is completed, the reaction is continued at 30-40°C for 3-4 h to fully complex the metal ions with the composite chelating agent precursor; The solid powder obtained by drying is the chelated trace element.

[0027] The chelated trace elements prepared by the chelation process of the present invention are more stable in the soil and are not easily fixed, and can effectively improve the absorption efficiency of bananas for trace elements such as iron, zinc, and manganese, thereby meeting the growth requirements of bananas.

[0028] Iron is involved in the electron transfer in photosynthesis, zinc is a component and activator of various enzymes, and has a promoting effect on the synthesis of pectin substances in the cell wall, making the cell wall tighter, and manganese is involved in the synthesis of cell wall structural substances, enhancing the stability of the cell wall, and manganese also plays an important role in photosynthesis and respiration. The active groups of polyaspartic acid can form stable coordination bonds with metal ions such as iron, zinc, and manganese, wrapping the metal ions inside the molecular structure, providing a basis for the subsequent formation of stable chelates. In addition, polyaspartic acid itself has a certain anti-soil fixation ability, and its molecular structure can prevent metal ions from combining with ions such as phosphates and carbonates in the soil that are easy to form precipitation, thereby increasing the stability of chelated trace elements in the soil. The functional groups of glycine: glutamic acid: lysine complement each other in spatial structure, and synergize with polyaspartic acid to further enhance the chelating ability of metal ions and form a more stable chelating environment. The chelated trace elements prepared by the present invention have a stable chemical structure and exist in the soil solution in the form of relatively independent chelates. This structure is not easily adsorbed and fixed by soil particles, and can get closer to banana roots as soil solution flows. When chelated trace elements reach the root surface, due to their stable structure and certain hydrophilicity, they are more likely to enter the cells through transport proteins on the root cell membrane, thereby effectively improving the banana's absorption efficiency of trace elements such as iron, zinc, and manganese, meeting the banana's growth needs, improving fruit quality and crack resistance, and reducing fruit cracking.

[0029] The present invention at least includes the following beneficial effects: First, the present invention provides a comprehensive and continuous nutrient supply for banana growth by applying different fertilizers at different growth stages. Apply amino acid and humic acid liquid fertilizers in the early stage to promote plant growth and nutrient accumulation; apply fertilizers and thin flowers and fruits rationally during the budding period to ensure that there are sufficient nutrients for fruit growth and that they are evenly distributed; apply calcium fertilizer and compound fertilizer during the young fruit stage to enhance the strength of the fruit cell wall. Accurately control soil moisture to create a stable environment for banana growth, effectively reduce fruit cracking, improve fruit quality and yield, and increase the economic benefits of growers.

[0030] Second, the present invention adopts a compounding ratio of 1:10 between the sum of the mass of humic acid and trace elements. This ratio enables humic acid to fully wrap and complex the trace elements, fully utilizes the good adsorption and ion exchange properties of humic acid, reduces the fixation and loss of trace elements in the soil, and improves the effectiveness and utilization rate of trace elements.

[0031] Third, the nano-silicon dioxide of the present invention is surface-modified, has a large specific surface area and strong adsorption, provides a stable and efficient carrier for subsequent compounding, improves the dispersion and stability of the compound in the soil, and is beneficial to root absorption; by compounding polyethyleneimine with the modified nano-silicon dioxide, the adsorption of humic acid-trace element complex is enhanced, the surface charge and chemical properties are adjusted, and the nutrient utilization efficiency is improved. The present invention fully combines trace elements with humic acid through step-by-step complexation and compounding, and uses a composite carrier to stably protect the complex, thereby achieving continuous nutrient supply and ensuring fruit development and quality improvement.

[0032] Fourth, the present invention uses root fertilizer to provide nitrogen, phosphorus, potassium macroelements and some trace elements to meet the rapid growth needs of bananas during the budding period. The biochar-based phosphorus fertilizer in the root fertilizer slowly releases phosphorus, which cooperates with the phosphorus in the root fertilizer to ensure that bananas have a stable phosphorus supply at different growth stages.

[0033] Fifth, the components of the root protection fertilizer in the present invention work synergistically to effectively avoid the problem of element antagonism. Biocarbon-based phosphate fertilizer and humic acid improve the soil, enhance the stability of each element in the fertilizer, and reduce mutual antagonistic interference. Amino acid-compounded calcium ensures a stable supply of calcium elements to avoid inhibition of calcium absorption due to excessive other cations. Phosphorus- and potassium-dissolving bacteria and arbuscular mycorrhizal fungal spores can promote the absorption and utilization of phosphorus and potassium elements, keep them in balance with other elements, and prevent the intake of other elements from being affected by excessive phosphorus and potassium. Seaweed oligosaccharides regulate plant physiological metabolism and help plants better coordinate the absorption of various elements. Starch-based slow-release agents slowly release nutrients, maintain a reasonable ratio between elements, provide a stable element environment for banana growth, reduce fruit cracking, and improve yield and quality.

[0034] Sixth, the chelating agent prepared by the present invention with polyaspartic acid and amino acid in proportion can be tightly combined with metal ions in fertilizer to form a stable chelate. This can not only prevent the metal ions from being fixed in the soil and reducing the effectiveness, but also promote the transportation and absorption of metal ions in banana plants, improve the utilization rate of fertilizers, reduce fertilizer waste, and reduce planting costs.

[0035] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. DETAILED DESCRIPTION

[0036] The present invention is described in further detail below so that those skilled in the art can implement it according to the description.

[0037] It should be understood that terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0038] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial channels unless otherwise specified.

[0039] <Example 1> A banana anti-cracking fruit planting method comprises the following steps: Step 1: Apply 3000 kg of decomposed organic fertilizer to each mu of land, till the soil and make ridges with a height of 30 cm and a width of 2 m. Plant banana seedlings at a spacing of 2 m between plants and 2.5 m between rows. Apply amino acid liquid fertilizer every 18 days. The amino acid liquid fertilizer can be FISH PROTEIN fish protein puree. Dilute the amino acid liquid fertilizer 100 times at a dosage of 30 L per mu and then drip irrigate. Apply humic acid liquid fertilizer every 15 days. The humic acid liquid fertilizer can be Kunlunfeng humic acid water-soluble fertilizer. The dosage is 25 L per mu and diluted 120 times. Apply trace elements when the banana is about to bud (i.e., at the top center of the pseudostem, there are signs of slight bulge or deformation). Continue planting until the banana buds. The trace elements include boron, zinc, iron, manganese and molybdenum, and 100 g of boron, 150 g of zinc, 200 g of iron, 100 g of manganese and 10 g of molybdenum are applied per mu of land; Among them, the trace elements are also compounded with humic acid, and the ratio of the sum of the masses of humic acid and trace elements is 1:10.

[0040] The method for compounding trace elements and humic acid comprises the following steps: Nano-silica was dispersed in anhydrous ethanol and subjected to ultrasonic treatment for 30 min to be fully dispersed, 3-aminopropyltriethoxysilane was added dropwise thereto, the mass ratio of 3-aminopropyltriethoxysilane to nano-silica was 1:5, and the mixture was stirred and reacted at 60°C for 6 h to graft 3-aminopropyltriethoxysilane onto the surface of nano-silica. After the reaction, the surface-modified nano-silica was obtained by centrifugation and washing. The surface-modified nano-silica was redispersed in deionized water, polyethyleneimine was added, and the mixture was stirred and reacted at room temperature for 3 h, so that the polyethyleneimine was compounded with the nano-silica through chemical bonding and physical adsorption to form a nano-silica-polyethyleneimine composite carrier; Dissolve the above-mentioned trace element fertilizers in water, stir them thoroughly to make them completely dissolved, and obtain a trace element fertilizer solution; Dissolve humic acid in water, then slowly add the trace element fertilizer solution into the humic acid solution, stirring while adding, and react at room temperature for 1 h to form a preliminary humic acid-trace element complex; The prepared nano-silica-polyethyleneimine composite carrier was added to the humic acid-trace element complex solution at a mass ratio of 1:3, and the reaction was continued by stirring for 3 hours. After the reaction was completed, the solution was dried to obtain the trace elements treated with humic acid. Step 2. During the budding period, apply root fertilizer every 5 days. The root fertilizer includes Litian Funong 30-10-10+TE, Litian Funong 5-5-45+TE (Litian Funong 30-10-10+TE and Litian Funong 5-5-45+TE are both from Bell Shell Bioengineering (Hubei) Co., Ltd.) and potassium chloride. Litian Funong 30-10-10+TE 11 g / plant, Litian Funong 5-5-45+TE 11 g / plant, potassium chloride 15 g / plant. After mixing the three fertilizers, apply ring ditch at a distance of 30 cm from the roots of banana plants; apply root fertilizer every 15 days, 30 g of root fertilizer per plant. The root fertilizer is 200 g of biological carbon-based phosphate fertilizer, 20 g of amino acid calcium, 10 g of phosphate and potassium solubilizing bacteria preparation, 5 g of arbuscular mycorrhizal fungal spore preparation, 40 g of seaweed oligosaccharides, and 50 g of humic acid. g, 30 g starch-based slow-release agent and 40 g bentonite. After fully mixing the ingredients in a blender, spread them around the plants and shallowly turn them into the soil 10 cm. After the flower buds emerge, when the inflorescence opens to the sixth female flower, use a knife to cut off the buds of neutral flowers and male flowers, and keep the healthy female flowers. In the early stage of banana fruit development, according to the growth and nutritional status of the plants, keep 7 bunches of fruits per banana plant, and keep 15 fruit fingers per bunch of fruit. Among them, the number of viable bacteria of phosphate and potassium solubilizing bacteria reached 4×10 8 spores / g, arbuscular mycorrhizal fungi spores ≥120 / g; The preparation of biological carbon-based phosphate fertilizer comprises the following steps: The rice husk biochar was crushed to 100 mesh, and potassium dihydrogen phosphate was dissolved in deionized water to prepare a solution with a concentration of 0.5 mol / L; Rice husk biochar was added to potassium dihydrogen phosphate solution, and the solid-liquid ratio of biochar to solution was controlled at 1:5. A magnetic stirrer was used to stir at 200 r / min for 2 h at room temperature to allow potassium dihydrogen phosphate to be fully adsorbed on the surface of biochar. Subsequently, the reaction system was transferred to a constant temperature water bath and stirred at 50 °C for 4 h. After the reaction, the mixture was centrifuged at 8000 r / min for 10 min to precipitate the biochar-based phosphate fertilizer, the supernatant was removed, and the precipitate was placed in a drying oven and dried at 40 °C for 6 hours to obtain dry biochar-based phosphate fertilizer. The biocarbon-based phosphate fertilizer is also subjected to the following treatment, which specifically comprises the following steps: Dissolve 2 g of polymethacrylic acid in 100 mL of anhydrous ethanol and stir magnetically for 30-60 min until it is completely dissolved to obtain a uniform polymethacrylic acid solution. Add 0.5 g of nano-silica to 50 mL of anhydrous ethanol and disperse by ultrasonication for 30 min to uniformly disperse the nano-silica in the ethanol solution. The dispersed nano-silica ethanol solution was slowly added dropwise to the polymethacrylic acid solution while stirring. The adding time was 15 min. After the addition was completed, 0.05 g of the cross-linking agent N, N'-methylenebisacrylamide was added and stirred for 30 min to fully mix. Then the reaction system was transferred to a reactor and reacted at 60 °C for 5 h. During the reaction, stirring was continued to promote the composite reaction between polymethacrylic acid and nano-silica. After the reaction, the reaction solution was cooled to room temperature and centrifuged at 8000 r / min for 10 min to precipitate the polymer-silica composite structure. The supernatant was removed and the precipitate was washed with anhydrous ethanol for 3 times. After each washing, the solution was centrifuged again to remove unreacted raw materials and impurities. The washed precipitate was placed in a vacuum drying oven and dried at 40°C for 6 h to obtain a dry polymer-silicon dioxide composite structure product, and the dried product was ground into powder using a mortar to obtain a polymer-silicon dioxide composite powder; The polymer-silicon dioxide composite powder and the biocarbon-based phosphate fertilizer were poured into a mixing container at a ratio of 1:10, and the agitator was turned on and set to low speed stirring at 100 r / min for 5 min to make the materials dispersed initially; then the speed was adjusted to medium speed at about 300 r / min and stirred for 10 min to ensure that the two were fully mixed. Step 3: When the banana fruitlets are combed upward, apply compound fertilizer rich in calcium every 10 days, with an application rate of 10 kg per mu, and continue planting until harvest; The compound fertilizer rich in calcium is made from the following raw material components: 30 g of calcium nitrate, 20 g of potassium dihydrogen phosphate, 15 g of magnesium sulfate, 10 g of chelated trace elements, 10 g of biochar, 2 g of microbial agent and 10 g of chelating agent; The microbial agent is composed of 30 g of Bacillus subtilis, 25 g of Bacillus licheniformis and 25 g of Bacillus amyloliquefaciens; The preparation of the composite fertilizer rich in calcium comprises the following steps: Calcium nitrate, potassium dihydrogen phosphate, magnesium sulfate and chelated trace elements are crushed separately to make the particle size reach 80-100 mesh; The biochar is crushed and sieved to a particle size of 80-100 mesh; Premix the microbial agent with vermiculite powder; Add the pretreated raw materials into a horizontal mixer according to the formula ratio, and stir them at a low speed of 100 r / min for 15 min to make the raw materials preliminarily mixed; then add the chelating agent, and then adjust the stirring speed to medium speed, at a speed of 200 r / min for 25 min to fully mix; The mixed materials are made into granular compound fertilizer by extrusion granulation process. During the granulation process, the temperature is controlled at 45 ℃. After granulation, the fluidized bed dryer is used for low-temperature drying, and the temperature is controlled at 50 ℃ to control the moisture content of the compound fertilizer below 5%. The dried compound fertilizer particles are screened, and a blend of polyvinyl alcohol and starch is used to coat the particles to obtain a compound fertilizer rich in calcium.

[0041] The preparation method of chelated trace elements comprises the following steps: Dissolve polyaspartic acid in deionized water to prepare a solution with a concentration of 15%, and use an ultrasonic disperser to perform ultrasonic treatment for 15 minutes to obtain a polyaspartic acid solution; the polyaspartic acid has a molecular weight of 3000-5000; The amino acid mixture was mixed in a molar ratio of glycine:glutamic acid:lysine = 3:2:1 to prepare a total concentration of 10% amino acid mixed solution, and ultrasonic treatment was also performed for 10 min; Ferrous sulfate, zinc sulfate and manganese sulfate are dissolved in deionized water to prepare a metal salt solution with a concentration of 10%, and filtered to remove insoluble impurities; The polyaspartic acid solution and the amino acid mixed solution were added into a container equipped with a stirrer, a thermometer and a reflux condenser in a volume ratio of 1:1. Under nitrogen protection, the temperature was slowly raised to 60 °C, the stirring speed was controlled at 200 r / min, and the reaction was carried out for 1 h. The reaction was completed to obtain a composite chelating agent precursor. The mixed solution was cooled to 30°C, and the metal salt solution was slowly added dropwise at a molar ratio of iron: zinc: manganese = 1:1:1. The addition time was controlled within 30 min, and stirring was performed while adding dropwise. After the addition was completed, the reaction was continued at 30°C for 3 h to fully complex the metal ions with the composite chelating agent precursor. The solid powder obtained by drying is the chelated trace element; Step 4: According to the maturity of bananas and market demand, when the bananas reach 7-8 degrees of maturity, choose to harvest before 9 am to avoid harvesting during high temperatures that will affect the fruit quality; During the entire planting period, soil moisture sensors are installed to monitor soil moisture in real time. When soil moisture is lower than 60%, appropriate water is added through the drip irrigation system; when soil moisture is higher than 80%, drainage channels are opened in time to drain water to ensure that soil moisture is always kept within the appropriate range.

[0042] <Effect Test> <Comparative Example 1> A banana anti-cracking fruit planting method comprises the following steps: Step 1: Apply 3000 kg of decomposed organic fertilizer to the field, till the soil and make ridges with a height of 30 cm and a width of 2 m. Plant banana seedlings at a spacing of 2 m between plants and 2.5 m between rows. Apply amino acid liquid fertilizer every 18 days. The amino acid liquid fertilizer can be FISH PROTEIN fish protein puree. Dilute the amino acid liquid fertilizer 100 times at a dosage of 30 L per mu of land and then drip irrigate. Apply humic acid liquid fertilizer every 15 days. The humic acid liquid fertilizer can be Kunlunfeng humic acid water-soluble fertilizer. The dosage is 25 L per mu of land, diluted 120 times. Apply trace elements (trace element water-soluble fertilizer-Haiwei No. 1) when the banana is about to bud. Continue planting until the banana buds. Step 2: During the budding period, apply root fertilizer every 5 days. The root fertilizer includes Litian Funong 30-10-10+TE, Litian Funong 5-5-45+TE (Litian Funong 30-10-10+TE and Litian Funong 5-5-45+TE are both from Bell Shell Bioengineering (Hubei) Co., Ltd.) and potassium chloride. Litian Funong 30-10-10+TE 11 g / plant, Litian Funong 5-5-45+TE 11 g / plant, potassium chloride 15 g / plant. Mix the three fertilizers and apply them in a ring ditch 30 cm away from the root of the banana plant; after the buds are drawn out, when the inflorescence opens to the sixth female flower, use a knife to remove the buds of the neutral and male flowers, and keep the healthy female flowers. In the early stage of banana fruit development, according to the growth and nutritional status of the plants, keep 7 bunches of fruits per banana plant, and keep 15 fruit fingers per bunch of fruit; Step 3: When the banana fruit is combing upward, apply compound fertilizer (Wandibao high tower compound fertilizer-banana fertilizer 17-5-29) every 10 days, with an application rate of 10 kg per mu, and continue planting until harvest; Step 4: According to the maturity of bananas and market demand, when the bananas reach 7-8 degrees of maturity, choose to harvest before 9 am to avoid harvesting during high temperatures that will affect the fruit quality; During the entire planting period, soil moisture sensors are installed to monitor soil moisture in real time. When soil moisture is lower than 60%, appropriate water is added through the drip irrigation system; when soil moisture is higher than 80%, drainage channels are opened in time to drain water to ensure that soil moisture is always kept within the appropriate range.

[0043] <Comparative Example 2> A method for planting bananas to prevent cracking is the same as that of Example 1, except that the trace elements are not compounded with humic acid for treatment.

[0044] <Comparative Example 3> A method for planting bananas to prevent cracking is the same as that of Example 1, except that no root protection fertilizer is applied.

[0045] <Comparative Example 4> A method for planting bananas to prevent cracking is the same as that of Example 1, except that the biocarbon-based phosphate fertilizer is not compounded with the polymer-silicon dioxide composite powder.

[0046] <Comparative Example 5> A method for planting bananas to prevent cracking is the same as that of Example 1, except that the calcium-rich compound fertilizer is replaced by Wandibao high-tower compound fertilizer-banana fertilizer 17-5-29.

[0047] <Comparative Example 6> A method for planting bananas to prevent cracking is the same as that of Example 1, except that chelated trace elements are replaced by ferrous sulfate, zinc sulfate and manganese sulfate, that is, raw materials pretreated with calcium nitrate, potassium dihydrogen phosphate, magnesium sulfate, ferrous sulfate, zinc sulfate and manganese sulfate are added into a horizontal mixer according to a formula ratio, fully mixed and then granulated and coated.

[0048] Eight banana trees were randomly selected, the number of cracked fruits on each banana tree was counted, and the average number of cracked fruits was calculated. The results are shown in Table 1.

[0049] Table 1 Number of cracked banana fruits per bunch As can be seen from the results in Table 1, Example 1 relies on scientific and reasonable planting methods and fertilizer application strategies to effectively control the overall fruit cracking situation. The average number of cracked fruits of 8-comb bananas is only 1, and the number of cracked fruits of some plants is 0. Comparative Example 1 uses conventional trace element water-soluble fertilizers, and the effectiveness and pertinence of nutrient supply are insufficient, resulting in a large number of cracked fruits, with an average number of cracked fruits of 3. Although Comparative Example 2 does not carry out a composite treatment of trace elements and humic acid, the overall planting method still has a certain effect, with an average number of cracked fruits of 2. Comparative Example 3 did not apply root fertilizer, which affected the root development and soil environment, and the average number of cracked fruits was 2.5. Comparative Example 4 The biocarbon-based phosphate fertilizer was treated, which can better provide a stable supply of phosphorus for banana growth compared to the untreated Comparative Example 3, and the average number of cracked fruits is 1.9. Comparative Example 5 The use of ordinary compound fertilizer instead of calcium-rich compound fertilizer cannot effectively enhance the strength of the fruit cell wall, and the number of cracked fruits is large, with an average number of cracked fruits of 3.1. In Comparative Example 6, the trace elements ferrous sulfate, zinc sulfate and manganese sulfate were not processed by boiling, which affected the absorption of bananas, and the average number of cracked fruits was 2.4. Through these data comparisons, it can be clearly seen that the technical solution of Example 1 has significant advantages in preventing cracked fruits, and it also shows that the missing technical links in each comparative example have different degrees of influence on the number of cracked fruits.

[0050] The banana yield and bunch index were statistically analyzed, and the results are shown in Table 2.

[0051] Table 2 Yield and ear index From the results in Table 2, it can be seen that the single-plant yield of Example 1 reaches 32.8 kg, far exceeding other comparative examples, which shows that the planting scheme of Example 1 can fully meet the nutrient requirements of banana growth, promote plant growth and fruit development, and greatly increase yield.

[0052] The cob weight of Example 1 was 3.85 kg, the heaviest among all groups. Cob weight is related to the overall growth of the plant. The planting method of Example 1 promoted the good development of all parts of the plant, making the cob heavier.

[0053] The fruit index weight of Example 1 is 28.95 kg, which is significantly higher than that of other comparative examples. The fruit index weight reflects the fullness and quality of the fruit. Through scientific fertilization and management, Example 1 allows the fruit to accumulate more nutrients, and the fruit index is heavier. The width of the fruit cluster of Example 1 is 39.85 cm, the length is 93 cm, and the thickness is 24 cm, all of which are the maximum values. These indicators of the fruit cluster reflect the growth space and development degree of the fruit. The planting plan of Example 1 provides better conditions for the growth of the fruit cluster, making it more advantageous in all aspects. Table 3 Nutritional indicators of bananas As can be seen from the data in Table 3, Example 1 performs best in various nutritional indicators. Its VC content reaches 30.86μg / g, indicating that the planting method of the present invention helps bananas accumulate more vitamin C and can improve the nutritional value and antioxidant capacity of bananas. The total sugar content is 213.6mg / g, and the soluble sugar content is 157.71mg / g, which shows that the planting method of Example 1 can promote the synthesis and accumulation of banana sugars, making the fruit sweeter and better in taste. The sucrose content is 110.91mg / g and the starch content is 82.44mg / g, reflecting that the present invention has good effects in the accumulation and conversion of carbohydrates. The soluble solids content is 19.19%, which reflects the richness of soluble substances in the fruit, and further confirms the high quality of bananas under the planting method of Example 1.

[0055] From the data in Table 3, it can be seen that the nutritional indicators of bananas under different planting treatments are significantly different, which fully demonstrates that factors such as fertilizer selection, fertilization timing, and fertilizer efficiency management in the soil in the planting method have a significant impact on the synthesis and accumulation of banana nutrients. After optimizing these factors, the planting method of Example 1 can significantly improve the nutritional quality of bananas.

[0056] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. A method for planting bananas to prevent cracking, characterized in that: The following steps are involved: Step 1: Apply decomposed organic fertilizer to the field, till the soil and make ridges, plant banana seedlings, apply amino acid liquid fertilizer every 15-20 days, apply humic acid liquid fertilizer every 10-15 days, and apply trace elements when the bananas are about to bud, and continue planting until the bananas bud; Step 2: During the budding period, apply root fertilizer every 5-6 days and root mulch fertilizer every 15 days. After the buds are drawn, when the inflorescence opens to the 5th to 8th female flowers, use a knife to remove the buds of neutral and male flowers and retain healthy female flowers. In the early stage of banana fruit development, according to the growth and nutritional status of the plant, each banana plant should retain 6-8 bunches of fruits, and each bunch of fruits should retain 14-16 fruit fingers; Step 3: When the banana fruit is combing upward, apply compound fertilizer rich in calcium every 10-15 days, with an application rate of 10-15 kg per mu, and continue planting until harvest; Step 4: Harvest bananas in a timely manner according to the maturity of bananas and market demand; During the entire planting period, soil moisture is maintained between 60-80%.

2. The banana fruit cracking prevention planting method according to claim 1, characterized in that: The trace elements include boron, zinc, iron, manganese and molybdenum. 100 parts of boron, 150 parts of zinc, 200 parts of iron, 100 parts of manganese and 10 parts of molybdenum are applied per mu of land.

3. The banana fruit cracking prevention planting method according to claim 2, characterized in that: Trace elements are compounded with humic acid, and the ratio of the sum of the masses of humic acid and trace elements is 1:

10.

4. The banana crack prevention planting method according to claim 3, characterized in that: The method for compounding trace elements and humic acid comprises the following steps: Dispersing nano-silica in anhydrous ethanol, ultrasonically treating for 30-60 min to fully disperse it, adding 3-aminopropyltriethoxysilane dropwise thereto, the mass ratio of 3-aminopropyltriethoxysilane to nano-silica being 1:5-1:8, stirring and reacting at 60-80 °C for 6-8 h to graft 3-aminopropyltriethoxysilane onto the surface of nano-silica, and after the reaction is completed, centrifuging and washing to obtain surface-modified nano-silica; The surface-modified nano-silica is re-dispersed in deionized water, polyethyleneimine is added, and the mixture is stirred and reacted for 2-3 hours at room temperature to allow the polyethyleneimine to be compounded with the nano-silica through chemical bonding and physical adsorption to form a nano-silica-polyethyleneimine composite carrier; Dissolve the above-mentioned trace element fertilizers in water, stir them thoroughly to make them completely dissolved, and obtain a trace element fertilizer solution; Dissolve humic acid in water according to the ratio, then slowly add the trace element fertilizer solution into the humic acid solution, stirring while adding, and react at room temperature for 1-2 hours to form a preliminary humic acid-trace element complex; The prepared nano-silica-polyethyleneimine composite carrier is added to the humic acid-trace element complex solution, and the reaction is continued by stirring for 3-4 hours. After the reaction is completed, the humic acid-trace element complex is obtained by drying.

5. The banana crack prevention planting method according to claim 1, characterized in that: Root fertilizers include Litian Funong 30-10-10+TE, Litian Funong 5-5-45+TE and potassium chloride. Litian Funong 30-10-10+TE is 11 g per plant, Litian Funong 5-5-45+TE is 11 g / plant, and potassium chloride is 15 g / plant.

6. The method for planting bananas to prevent cracking according to claim 1, characterized in that: The root fertilizer includes 200 parts of biological carbon-based phosphate fertilizer, 20 parts of amino acid calcium, 10 parts of phosphate-dissolving and potassium-dissolving bacteria preparation, 5 parts of arbuscular mycorrhizal fungal spore preparation, 40 parts of seaweed oligosaccharides, 50 parts of humic acid, 30 parts of starch-based slow-release agent and 40 parts of bentonite; among them, the number of live bacteria of phosphate-dissolving and potassium-dissolving bacteria reaches 3×10 8 -4×10 8 pcs / portion, arbuscular mycorrhizal fungal spores ≥120 pcs / portion.

7. The method for planting bananas to prevent cracking according to claim 6, characterized in that: The biocarbon-based phosphate fertilizer is also subjected to the following treatment, which specifically comprises the following steps: Dissolve 2 g of polymethacrylic acid in 100 mL of anhydrous ethanol and stir magnetically for 30-60 min until it is completely dissolved to obtain a uniform polymethacrylic acid solution. Add 0.5 g of nano-silica to 50 mL of anhydrous ethanol and disperse by ultrasonic for 30 min to evenly disperse the nano-silica in the ethanol solution. Slowly drop the dispersed nano-silica ethanol solution into the polymethacrylic acid solution while stirring. The dropping time is 15-20 min. After the dropping is completed, add 0.05 g of cross-linking agent N, N'-methylenebisacrylamide and continue stirring for 30 min to fully mix. Then transfer the reaction system to a reactor and react at 60-70 ° C for 4-6 h. During the reaction, continue stirring to promote the composite reaction of polymethacrylic acid and nano-silica. After the reaction is completed, the reaction solution is cooled to room temperature, centrifuged at a speed of 8000-10000 r / min for 10-15 min to precipitate the polymer-silica composite structure, the supernatant is removed, and the precipitate is washed with anhydrous ethanol 3-4 times, and centrifuged again after each washing to remove unreacted raw materials and impurities; The washed precipitate is placed in a vacuum drying oven and dried at 40-50°C for 6-8 hours to obtain a dry polymer-silicon dioxide composite structure product, and the dried product is ground into powder using a mortar to obtain a polymer-silicon dioxide composite powder; Pour the polymer-silica composite powder and the biocarbon-based phosphate fertilizer into a mixing container at a ratio of 1:10, turn on the mixer, set the low-speed stirring to 100-200 r / min, stir for 5-10 min to initially disperse the materials; then adjust to medium speed to about 300-400 r / min, stir for 10-15 min to ensure that the two are fully mixed.

8. The method for planting bananas to prevent cracking according to claim 1, characterized in that: The compound fertilizer rich in calcium is made of the following raw material components: 30-30 parts of calcium nitrate, 15-20 parts of potassium dihydrogen phosphate, 10-15 parts of magnesium sulfate, 5-10 parts of chelated trace elements, 5-10 parts of biochar, 1-2 parts of microbial agents and 5-10 parts of chelating agents; The chelating agent is prepared by dissolving polyaspartic acid and amino acid in water at a mass ratio of 2:1 to prepare a solution with a mass ratio of 10% of the chelating agent; Microbial agents include Bacillus subtilis, Bacillus licheniformis and Bacillus amyloliquefaciens.

9. The method for planting bananas to prevent cracking according to claim 8, characterized in that: The preparation of the composite fertilizer rich in calcium comprises the following steps: Calcium nitrate, potassium dihydrogen phosphate, magnesium sulfate and chelated trace elements are crushed separately to make the particle size reach 80-100 mesh; The biochar is crushed and sieved to a particle size of 80-100 mesh; Premix the microbial agent with vermiculite powder; Add the pretreated raw materials into a horizontal mixer according to the formula ratio, and stir them at a low speed of 100-150 r / min for 15-20 min to initially mix the raw materials; then add the chelating agent, and then adjust the stirring speed to medium speed, at a speed of 200-300 r / min for 25-35 min to fully mix; The mixed materials are made into granular compound fertilizer by extrusion granulation process. During the granulation process, the temperature is controlled at 45-60 ℃. After granulation, the fluidized bed dryer is used for low-temperature drying, and the temperature is controlled at 50-60 ℃ to control the moisture content of the compound fertilizer below 5%; The dried compound fertilizer particles are screened, and a blend of polyvinyl alcohol and starch is used to coat the particles to obtain a compound fertilizer rich in calcium.

10. The method for planting bananas to prevent cracking according to claim 8, characterized in that: The preparation method of chelated trace elements comprises the following steps: Dissolve polyaspartic acid in deionized water to prepare a solution with a concentration of 15%-20%, and use an ultrasonic disperser to perform ultrasonic treatment for 15-20 minutes to obtain a polyaspartic acid solution; the polyaspartic acid has a molecular weight of 3000-5000; The amino acid mixture was mixed in a molar ratio of glycine: glutamic acid: lysine = 3:2:1 to prepare a total concentration of 10%-15% amino acid mixed solution, and ultrasonic treatment was also performed for 10-15 minutes; Ferrous sulfate, zinc sulfate and manganese sulfate are dissolved in deionized water to prepare a metal salt solution with a concentration of 10%-15%, and filtered to remove insoluble impurities; Add the polyaspartic acid solution and the amino acid mixed solution in a volume ratio of 1:1-1:1.5 into a container equipped with a stirrer, a thermometer and a reflux condenser, slowly heat to 60-70 °C under nitrogen protection, control the stirring speed at 200-300 r / min, react for 1-2 h, and end the reaction to obtain a composite chelating agent precursor; The mixed solution is cooled to 30-40°C, and the metal salt solution is slowly added dropwise according to the molar ratio of iron: zinc: manganese = 1:1:

1. The addition time is controlled within 30-45 min, and stirring is performed while adding. After the addition is completed, the reaction is continued at 30-40°C for 3-4 hours to fully complex the metal ions with the composite chelating agent precursor; The solid powder obtained by drying is the chelated trace element.

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