Slow-release citrus planting fertilization process

Abstract

The invention discloses a slow-release citrus planting fertilization process, which belongs to the field of planting, and comprises the following steps: digging a fertilization pit with the depth of 35-40cm in a field ditch on one side of a citrus fruit tree planting area, the horizontal linear distance between the position of the fertilization pit and the surrounding citrus fruit tree being 0.6-1m; a plurality of bamboo tubes of 30 centimeters are obtained, the tops of the bamboo tubes are completely open, bamboo joints are arranged at the lower ends of the bamboo tubes, through holes communicating with the interiors of the bamboo tubes are formed in the bamboo joints at the lower ends of the bamboo tubes, and the through holes are plugged through soft plugs; liquid fertilizer, a water-retaining agent and organic copper are filled in the bamboo tubes, then the openings in the tops of the bamboo tubes are sealed through bamboo tube covers, soft plugs of the through holes are pulled out to open the through holes in the bamboo joints at the lower ends of the bamboo tubes, then the bamboo tubes are placed in the fertilization pits, and a plurality of bamboo tubes filled with the liquid fertilizer, the water-retaining agent and the organic copper are placed in each fertilization pit. The bamboo tube is used as a carrier of the liquid fertilizer, and the water-retaining agent is combined, so that on one hand, the fertilizer can be prevented from being lost;

Description

Technical Field

[0001] The invention belongs to the field of planting and relates to a slow-release citrus planting fertilization process. Background Art

[0002] At present, in the process of planting citrus and other fruit trees, for root fertilization, fertilizers are generally buried directly around the fruit trees, which will lead to nutrient waste due to rain erosion and fertilizer volatilization; or, if quick-acting fertilizers release a large amount of nutrients at one time, and the citrus trees cannot fully absorb them in a short period of time, it will also cause nutrient waste; when a large amount of fertilizer nutrients are wasted, the fruit trees cannot get enough nutrients, and frequent fertilization will occur. Frequent fertilization not only causes a large loss of fertilizer, but also leads to soil acidification, compaction and other problems, affecting the activity of soil microorganisms and soil fertility. Summary of the invention

[0003] The purpose of the present invention is to provide a slow-release citrus planting fertilization process, which solves the problem that the current traditional root fertilization method will cause a large amount of fertilizer nutrients to be lost, and the fruit trees cannot obtain a stable and continuous nutrient supply throughout the entire growth cycle.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A slow-release citrus planting fertilization process comprises the following steps:

[0006] S1. Dig a fertilizer pit with a depth of 35-40 cm in the field ditch on one side of the citrus tree planting area. The horizontal straight-line distance between the fertilizer pit and the surrounding citrus trees is 0.6-1 m.

[0007] S2, obtaining a plurality of 30-cm bamboo tubes, wherein the tops of the bamboo tubes are completely open, the lower ends of the bamboo tubes are provided with bamboo nodes, and the bamboo nodes at the lower ends of the bamboo tubes are provided with through holes connected to the inside of the bamboo tubes, and the through holes are blocked by soft plugs;

[0008] S3, liquid fertilizer, water retaining agent and organic copper are loaded into the bamboo tube in step S2, and then the opening at the top of the bamboo tube is sealed with a bamboo tube cover, and then the soft plug of the through hole is pulled out to open the through hole on the bamboo node at the lower end of the bamboo tube, and then the bamboo tube is placed in a fertilization pit, and multiple bamboo tubes filled with liquid fertilizer, water retaining agent and organic copper are placed in each fertilization pit.

[0009] The present invention uses bamboo tubes as containers for liquid fertilizers, which can effectively prevent the liquid fertilizers from volatilizing and losing. The present invention opens small holes for the common fertilizer to flow out on the bamboo tubes, and the fertilizers slowly flow out of the bamboo tubes for absorption by the roots of fruit trees. The fertilizers released into the soil each time are less, and the fruit trees will not be unable to fully absorb them in a short time, resulting in the problem of nutrient waste. The present invention adds water retaining agent and organic copper to the liquid fertilizers, and the slow-release effect of the water retaining agent can delay the release speed of the fertilizers, so that the nutrients in the fertilizers are continuously and stably supplied to the plants in the soil. The organic copper plays a role of sterilization, and can effectively avoid the situation that the liquid fertilizers are stored in the bamboo tubes for a long time and deteriorate. In addition, copper is one of the trace elements required for plant growth, and the organic copper preparation can provide copper elements for plants, promoting the normal growth and development of plants. The present invention uses bamboo tubes as carriers for liquid fertilizers, and in combination with water retaining agents, on the one hand, can prevent the fertilizers from being lost, and on the other hand, slowly release the fertilizers into the soil, playing a role of slow-release fertilization. Slow-release fertilization can slowly release nutrients, so that citrus trees can obtain a stable and continuous supply of nutrients throughout the growth cycle. This can not only reduce nutrient loss and waste caused by excessive one-time fertilization, but also improve nutrient utilization efficiency; the organic components in slow-release fertilizers can be gradually released into the soil, improving soil structure, soil fertility and water and fertilizer retention capabilities. At the same time, it can also reduce the use of chemical fertilizers and reduce the risk of soil acidification and compaction.

[0010] Furthermore, step S2 also includes the following steps: coating the inner wall of the bamboo tube with a treatment agent, wherein the treatment agent includes component A and component B;

[0011] The component A comprises the following components: macromolecular tannic acid, metal ions, and polysaccharide-peptide conjugates; wherein the mass ratio of macromolecular tannic acid, metal ions, and polysaccharide-peptide conjugates is 1:1:3.5;

[0012] The component B is a plant fiber modified polyethylene degradable film;

[0013] The processing method is:

[0014] S2.1 Preparation of component A: Dissolve macromolecular tannic acid and metal ions in deionized water to obtain macromolecular tannic acid solution and metal ion solution respectively, then evenly mix the macromolecular tannic acid solution and metal ion solution and stir to react at 40°C, continue to stir to react for 1 hour, add polysaccharide-peptide conjugate, heat to 50°C, continue to stir to react at 50°C for 1.5 hours, and obtain component A;

[0015] S2.2 Preliminary treatment of the inner wall of the bamboo tube: spray component A evenly on the inner wall of the bamboo tube, perform UV curing on the inner wall of the bamboo tube, and obtain a semi-cured adhesive layer after curing for 10 minutes;

[0016] S2.3 Preparation of component B: obtaining long-fiber wood pulp, long-fiber hemp pulp, and long-fiber sedge pulp, uniformly mixing the long-fiber wood pulp, long-fiber hemp pulp, and long-fiber sedge pulp to obtain plant fiber pulp, selecting linear low-density polyethylene as a substrate, heating the linear low-density polyethylene to a molten state, and then mixing the plant fiber pulp with the linear low-density polyethylene in a molten state, and adding a curing agent to form a uniform melt; then uniformly spraying the melt on the semi-solidified adhesive layer on the inner wall of the bamboo tube that has been preliminarily treated in step S2.2, heating and curing at 90-100°C, forming a plant fiber modified polyethylene degradable film on the adhesive layer, the adhesive layer and the plant fiber modified polyethylene degradable film are completely cured, and the adhesive layer is tightly connected to the plant fiber modified polyethylene film and the inner wall of the bamboo tube. The bamboo tube used for holding liquid fertilizer, water-retaining agent and organic copper in step S3 is a bamboo tube whose inner wall has been treated with component A and component B.

[0017] Since the bamboo charcoal component on the inner wall of the bamboo tube has a strong adsorption capacity, it can adsorb small molecules, including certain nutrients in the fertilizer; therefore, in order to prevent the inner wall of the bamboo tube from adsorbing some nutrients in the fertilizer and to avoid the waste of nutrients in the fertilizer; the present invention performs a film coating treatment on the inner wall of the bamboo tube, so that the inner wall of the bamboo tube forms a film with strong adhesion but no adsorption effect; the component A in the present invention has a strong adsorption capacity, which can be adsorbed on the inner wall of the bamboo tube and can be tightly adhered to the plant fiber modified polyethylene degradable film, the plant fiber modified polyethylene degradable film is in contact with the fertilizer, the plant fiber modified polyethylene degradable film has the non-polar properties of the polyethylene film, and has no adhesion and adsorption functions to the fertilizer; since the degradation rate of the polyethylene film is slow, the present invention uses plant fibers to modify the polyethylene film, thereby accelerating the degradation rate of the polyethylene film.

[0018] The principle of the tight adhesion of component A to the inner wall of the bamboo tube and the plant fiber modified polyethylene degradable film is:

[0019] The macromolecular tannic acid has multiple ortho-phenol structures. These phenolic groups, as multi-radical ligands, combine with metal ions through coordination bonds to form a complex. This multi-coordinate bond structure allows the complex to remain stable under a variety of environmental conditions, including water-soluble environments caused by liquid fertilizers and different pH environments caused by different types of liquid fertilizers. The present invention utilizes the stability of the complex so that component A can have a stable structure during long-term immersion in liquid fertilizers. Although the complex has a relatively stable structure, the adhesion of the complex to the inner wall of the bamboo tube and the polyethylene film is relatively weak. Therefore, after the tannic acid forms a complex with the metal ions, the present invention adds a polysaccharide-peptide conjugate. In the polysaccharide-peptide conjugate, the chain structure of the polysaccharide acts as a bridge to connect the tannic acid-metal ion complex with the inner wall of the bamboo tube and the polyethylene film. This bridging effect can increase the contact area and interaction force between the complex and the interface, thereby improving the adhesion effect. The polysaccharide-peptide conjugate molecules have a large volume and a complex structure. When they are introduced into When the complex is between the bamboo tube inner wall, it will occupy a certain spatial position. This macromolecular structure interacts with the complex and the bamboo tube inner wall, including van der Waals force and hydrogen bond, so that the gap between the complex and the bamboo tube inner wall is filled, thereby changing the spatial conformation of the entire system and preventing excessive movement and rearrangement of molecules; the polysaccharide part in the polysaccharide-peptide conjugate has abundant active groups such as hydroxyl and carboxyl groups, and these functional groups can form hydrogen bonds and electrostatic interactions with cellulose and hemicellulose on the surface of the bamboo tube inner wall; at the same time, the tannic acid in the tannic acid-metal ion complex also contains multiple phenolic hydroxyl groups, which can form hydrogen bonds and electrostatic interactions with the groups on the surface of the polysaccharide and the bamboo tube inner wall; therefore, the addition of the polysaccharide-peptide conjugate increases the types and number of interfacial interaction forces and improves the interfacial compatibility of the entire system. When the interfacial compatibility is improved, the interfacial energy will be reduced, making it easier for the polyethylene film to spread and adhere to the inner wall of the bamboo tube through the composite system formed by the macromolecular tannic acid-metal ion complex and the polysaccharide-peptide conjugate.

[0020] Furthermore, the metal ions are magnesium ions or calcium ions or a mixture of the two.

[0021] Furthermore, the metal ions are a mixture of magnesium ions and calcium ions, and the mass ratio of magnesium ions to calcium ions is 1:1.

[0022] Furthermore, in step S2.3, the mass ratio of long fiber wood pulp, long fiber hemp pulp, and long fiber sedge pulp is 1:1.5:1.2.

[0023] Furthermore, the preparation method of the polysaccharide-peptide conjugate comprises the following steps: dissolving carboxylated seaweed polysaccharide in phosphate buffer, adjusting the pH to 7.4, and obtaining a carboxylated seaweed polysaccharide solution; dissolving arginine polypeptide and lysine polypeptide in phosphate buffer, and obtaining a mixed solution of arginine polypeptide and lysine polypeptide; preparing 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide solution and N-hydroxysuccinimide solution respectively; adding 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide solution to the carboxylated seaweed polysaccharide solution under stirring conditions, reacting at room temperature for 30 minutes, then adding N-hydroxysuccinimide solution, continuing to stir and react for 15 minutes, then slowly adding the mixed solution of arginine polypeptide and lysine polypeptide, stirring and reacting at 30°C for 12 hours, and finally adding glycine to terminate the reaction, and purifying to obtain the polysaccharide-peptide conjugate.

[0024] Furthermore, the carboxylated seaweed polysaccharide is prepared by the following method: dissolving seaweed polysaccharide in water to obtain a seaweed polysaccharide solution, then adding succinic anhydride and acetic acid to the seaweed polysaccharide solution under stirring conditions, continuing to stir and react at 25-30°C for 20 hours, and finally purifying, drying and dehydrating to obtain the carboxylated seaweed polysaccharide.

[0025] Furthermore, the bamboo tube cover is a hollow cylindrical cover that matches the shape of the bamboo tube and has an open bottom, and the bamboo tube cover is threadedly connected to the top of the bamboo tube.

[0026] Furthermore, the liquid fertilizer includes at least one of a water-soluble compound fertilizer containing nitrogen, phosphorus and potassium, an amino acid water-soluble fertilizer and a humic acid water-soluble fertilizer.

[0027] Furthermore, the water retaining agent is one of bentonite grafted potassium humate, starch-polyacrylamide type water retaining agent, polyvinyl alcohol type water retaining agent, and polyacrylamide type water retaining agent.

[0028] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0029] 1. The slow-release citrus planting fertilization process of the present invention uses bamboo tubes as containers for liquid fertilizers, which can effectively prevent the liquid fertilizers from volatilizing and losing. The present invention provides small holes for the outflow of fertilizers on the bamboo tubes, and the fertilizers slowly flow out of the bamboo tubes for absorption by the roots of fruit trees. The amount of fertilizers released into the soil each time is small, and the fruit trees will not be unable to fully absorb the fertilizers in a short time, resulting in a problem of nutrient waste;

[0030] 2. The present invention adds a water retaining agent and organic copper to the liquid fertilizer. The slow-release effect of the water retaining agent can delay the release rate of the fertilizer, so that the nutrients in the fertilizer can be continuously and stably supplied to the plants in the soil. The organic copper plays a bactericidal role, which can effectively prevent the liquid fertilizer from being deteriorated when stored in the bamboo tube for a long time.

[0031] 3. The present invention processes the inner wall of the bamboo tube and covers the inner wall of the bamboo tube with a film to avoid direct contact between the inner wall of the bamboo tube and the fertilizer, thereby preventing the inner wall of the bamboo tube from absorbing effective ingredients in the fertilizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative work, among which:

[0033] Figure 1 It is a fertilization chart for a slow-release citrus planting fertilization process;

[0034] Figure 2 This is a schematic diagram of the bamboo tube structure of the present invention; DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0037] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0038] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0039] The invention discloses a slow-release citrus planting fertilization process, comprising the following steps:

[0040] S1. Dig a fertilizer pit 1 with a depth of 35-40cm in the field ditch on one side of the citrus tree planting area. The horizontal straight-line distance between the location of the fertilizer pit 1 and the surrounding citrus trees is 0.6-1m. For fruit trees with younger age, the fertilizer pit cannot be too deep because the root system is shallow in the soil, but the fertilizer pit cannot be too close to the fruit tree, otherwise the roots will be burned. On the contrary, for fruit trees with older age, the root system is deeper in the soil and requires a deeper fertilizer pit. The horizontal distribution range of the fruit tree root system is mainly concentrated in the slightly farther part of the crown projection. Therefore, the fertilizer pit should be as close to the fruit tree root system as possible to ensure that the fertilizer can be quickly absorbed by the root system.

[0041] S2, obtaining a plurality of bamboo tubes 2 with a length of 30 cm, wherein the top of the bamboo tubes 2 is completely open, and the lower ends of the bamboo tubes 1 are provided with bamboo nodes, and the bamboo nodes at the lower ends of the bamboo tubes 1 are provided with through holes 21 connected to the inside of the bamboo tubes 2, and the through holes 21 are blocked by soft plugs;

[0042] S3, liquid fertilizer, water retaining agent and organic copper are loaded into the bamboo tube 2 in step S2, and then the opening at the top of the bamboo tube 2 is sealed with a bamboo tube cover 22, and then the soft plug of the through hole 21 is pulled out to open the through hole 21 on the bamboo node at the lower end of the bamboo tube 1, and then the bamboo tube 2 is placed in the fertilizer pit 1, and multiple bamboo tubes filled with liquid fertilizer, water retaining agent and organic copper are placed in each fertilizer pit 1.

[0043] The inner wall of the bamboo tube 2 is coated with a treatment agent, wherein the treatment agent includes component A and component B;

[0044] The component A comprises the following components: macromolecular tannic acid, metal ions, and polysaccharide-peptide conjugates; wherein the mass ratio of macromolecular tannic acid, metal ions, and polysaccharide-peptide conjugates is 1:1:3.5;

[0045] The component B is a plant fiber modified polyethylene degradable film;

[0046] The processing method is:

[0047] S2.1 Preparation of component A: Dissolve macromolecular tannic acid and metal ions in deionized water to obtain macromolecular tannic acid solution and metal ion solution respectively, then evenly mix the macromolecular tannic acid solution and metal ion solution and stir to react at 40°C, continue to stir to react for 1 hour, add polysaccharide-peptide conjugate, heat to 50°C, continue to stir to react at 50°C for 1.5 hours, and obtain component A;

[0048] S2.2 Preliminary treatment of the inner wall of the bamboo tube: spray component A evenly on the inner wall of the bamboo tube, perform UV curing on the inner wall of the bamboo tube, and obtain a semi-cured adhesive layer after curing for 10 minutes;

[0049] S2.3 Preparation of component B: obtaining long-fiber wood pulp, long-fiber hemp pulp, and long-fiber sedge pulp, uniformly mixing the long-fiber wood pulp, long-fiber hemp pulp, and long-fiber sedge pulp to obtain plant fiber pulp, selecting linear low-density polyethylene as a substrate, heating the linear low-density polyethylene to a molten state, and then mixing the plant fiber pulp with the linear low-density polyethylene in a molten state, and adding a curing agent to form a uniform melt; then uniformly spraying the melt on the semi-solidified adhesive layer on the inner wall of the bamboo tube that has been preliminarily treated in step S2.2, heating and curing at 90-100°C, forming a plant fiber modified polyethylene degradable film on the adhesive layer, the adhesive layer and the plant fiber modified polyethylene degradable film are completely cured, and the adhesive layer is tightly connected to the plant fiber modified polyethylene film and the inner wall of the bamboo tube. The bamboo tube used for holding liquid fertilizer, water-retaining agent and organic copper in step S3 is a bamboo tube whose inner wall has been treated with component A and component B.

[0050] The metal ions are magnesium ions or calcium ions or a mixture of the two.

[0051] Furthermore, the metal ions are a mixture of magnesium ions and calcium ions, and the mass ratio of magnesium ions to calcium ions is 1:1.

[0052] Furthermore, in step S2.3, the mass ratio of long fiber wood pulp, long fiber hemp pulp, and long fiber sedge pulp is 1:1.5:1.2.

[0053] The preparation method of the polysaccharide-peptide conjugate comprises the following steps: dissolving carboxylated seaweed polysaccharide in a phosphate buffer, adjusting the pH to 7.4, and obtaining a carboxylated seaweed polysaccharide solution; dissolving arginine polypeptide and lysine polypeptide in a phosphate buffer, and obtaining a mixed solution of arginine polypeptide and lysine polypeptide; respectively preparing a 1-3-dimethylaminopropyl-3-ethylcarbodiimide solution and an N-hydroxysuccinimide solution; adding the 1-3-dimethylaminopropyl-3-ethylcarbodiimide solution to the carboxylated seaweed polysaccharide solution under stirring conditions, reacting at room temperature for 30 minutes, subsequently adding the N-hydroxysuccinimide solution, continuing to stir and react for 15 minutes, then slowly adding the mixed solution of arginine polypeptide and lysine polypeptide, stirring and reacting at 30°C for 12 hours, and finally adding glycine to terminate the reaction, and purifying to obtain the polysaccharide-peptide conjugate.

[0054] The carboxylated seaweed polysaccharide is prepared by the following method: dissolving seaweed polysaccharide in water to obtain a seaweed polysaccharide solution, then adding succinic anhydride and acetic acid to the seaweed polysaccharide solution under stirring conditions, continuing stirring and reacting at 25-30° C. for 20 hours, and finally purifying, drying and dehydrating to obtain the carboxylated seaweed polysaccharide.

[0055] The bamboo tube cover 22 is a hollow cylindrical cover with an open bottom that matches the shape of the bamboo tube 1 . The bamboo tube cover 22 is threadedly connected to the top of the bamboo tube 1 .

[0056] The liquid fertilizer includes at least one of a water-soluble compound fertilizer containing nitrogen, phosphorus and potassium, an amino acid water-soluble fertilizer and a humic acid water-soluble fertilizer. The common components of the water-soluble compound fertilizer containing nitrogen, phosphorus and potassium, the amino acid water-soluble fertilizer and the humic acid water-soluble fertilizer are nitrogen, phosphorus and potassium nutrients.

[0057] The water retaining agent is one of bentonite grafted potassium humate, starch-polyacrylamide type water retaining agent, polyvinyl alcohol type water retaining agent and polyacrylamide type water retaining agent.

[0058] Example 1

[0059] like Figure 1 , Figure 2 As shown, a slow-release citrus planting fertilization process provided by a preferred embodiment of the present invention comprises the following steps:

[0060] S1. Dig a fertilizer pit 1 with a depth of 35 cm in the field ditch on one side of the citrus fruit tree planting area. The horizontal straight-line distance between the location of the fertilizer pit 1 and the surrounding citrus fruit trees is 1 m. The citrus fruit trees are 1 year old or less.

[0061] S2, obtaining a plurality of 30 cm bamboo tubes 2, wherein the top of the bamboo tubes 2 is completely open, the lower ends of the bamboo tubes 1 are provided with bamboo nodes, and the bamboo nodes at the lower ends of the bamboo tubes 1 are provided with through holes 21 communicating with the interior of the bamboo tubes 2, and the through holes 21 are blocked by soft plugs;

[0062] S3, liquid fertilizer, water retaining agent and organic copper are loaded into the bamboo tube 2 in step S2, and then the opening at the top of the bamboo tube 2 is sealed with a bamboo tube cover 22, and then the soft plug of the through hole 21 is pulled out to open the through hole 21 on the bamboo node at the lower end of the bamboo tube 1, and then the bamboo tube 2 is placed in the fertilizer pit 1, and multiple bamboo tubes filled with liquid fertilizer, water retaining agent and organic copper are placed in each fertilizer pit 1.

[0063] The inner wall of the bamboo tube 2 is coated with a treatment agent, wherein the treatment agent includes component A and component B;

[0064] The component A comprises the following components: macromolecular tannic acid, metal ions, and polysaccharide-peptide conjugates; wherein the mass ratio of macromolecular tannic acid, metal ions, and polysaccharide-peptide conjugates is 1:1:3.5;

[0065] The component B is a plant fiber modified polyethylene degradable film;

[0066] The processing method is:

[0067] S2.1 Preparation of component A: Dissolve macromolecular tannic acid and metal ions in deionized water to obtain macromolecular tannic acid solution and metal ion solution respectively, then evenly mix the macromolecular tannic acid solution and metal ion solution and stir to react at 40°C, continue to stir to react for 1 hour, add polysaccharide-peptide conjugate, heat to 50°C, continue to stir to react at 50°C for 1.5 hours, and obtain component A;

[0068] S2.2 Preliminary treatment of the inner wall of the bamboo tube: spray component A evenly on the inner wall of the bamboo tube, perform UV curing on the inner wall of the bamboo tube, and obtain a semi-cured adhesive layer after curing for 10 minutes;

[0069] S2.3 Preparation of component B: obtaining long-fiber wood pulp, long-fiber hemp pulp, and long-fiber sedge pulp, uniformly mixing the long-fiber wood pulp, long-fiber hemp pulp, and long-fiber sedge pulp to obtain plant fiber pulp, selecting linear low-density polyethylene as a substrate, heating the linear low-density polyethylene to a molten state, and then mixing the plant fiber pulp with the linear low-density polyethylene in a molten state, and adding a curing agent to form a uniform melt; then uniformly spraying the melt on the semi-solidified adhesive layer on the inner wall of the bamboo tube that has been preliminarily treated in step S2.2, heating and curing at 90-100°C, forming a plant fiber modified polyethylene degradable film on the adhesive layer, the adhesive layer and the plant fiber modified polyethylene degradable film are completely cured, and the adhesive layer is tightly connected to the plant fiber modified polyethylene film and the inner wall of the bamboo tube. The bamboo tube used for holding liquid fertilizer, water-retaining agent and organic copper in step S3 is a bamboo tube whose inner wall has been treated with component A and component B.

[0070] The metal ions are a mixture of magnesium ions and calcium ions, and the mass ratio of the magnesium ions to the calcium ions is 1:1.

[0071] In the step S2.3, the mass ratio of long fiber wood pulp, long fiber hemp pulp, and long fiber sedge pulp is 1:1.5:1.2.

[0072] The preparation method of the polysaccharide-peptide conjugate comprises the following steps: dissolving carboxylated seaweed polysaccharide in a phosphate buffer, adjusting the pH to 7.4, and obtaining a carboxylated seaweed polysaccharide solution; dissolving arginine polypeptide and lysine polypeptide in a phosphate buffer, and obtaining a mixed solution of arginine polypeptide and lysine polypeptide; respectively preparing a 1-3-dimethylaminopropyl-3-ethylcarbodiimide solution and an N-hydroxysuccinimide solution; adding the 1-3-dimethylaminopropyl-3-ethylcarbodiimide solution to the carboxylated seaweed polysaccharide solution under stirring conditions, reacting at room temperature for 30 minutes, subsequently adding the N-hydroxysuccinimide solution, continuing to stir and react for 15 minutes, then slowly adding the mixed solution of arginine polypeptide and lysine polypeptide, stirring and reacting at 30°C for 12 hours, and finally adding glycine to terminate the reaction, and purifying to obtain the polysaccharide-peptide conjugate.

[0073] The carboxylated seaweed polysaccharide is prepared by the following method: dissolving seaweed polysaccharide in water to obtain a seaweed polysaccharide solution, then adding succinic anhydride and acetic acid to the seaweed polysaccharide solution under stirring conditions, continuing stirring and reacting at 30° C. for 20 hours, and finally purifying, drying and dehydrating to obtain the carboxylated seaweed polysaccharide.

[0074] The bamboo tube cover 22 is a hollow cylindrical cover with an open bottom that matches the shape of the bamboo tube 1 . The bamboo tube cover 22 is threadedly connected to the top of the bamboo tube 1 .

[0075] The liquid fertilizer is a water-soluble compound fertilizer containing nitrogen, phosphorus and potassium.

[0076] The water retaining agent is a starch-polyacrylamide type water retaining agent.

[0077] Example 2

[0078] This embodiment is based on the embodiment 1, and the difference between this embodiment and the embodiment 1 is that the liquid fertilizer in this embodiment is amino acid water-soluble fertilizer; the rest is the same as the embodiment 1.

[0079] Example 3

[0080] This embodiment is based on the embodiment 1, and the difference between this embodiment and the embodiment 1 is that the liquid fertilizer in this embodiment is humic acid water-soluble fertilizer; the rest is the same as the embodiment 1.

[0081] Example 4

[0082] This embodiment is based on the embodiment 1. The difference between this embodiment and the embodiment 1 is that the water retaining agent in this embodiment is bentonite grafted potassium humate; the rest of the parts are the same as the embodiment 1.

[0083] Example 5

[0084] This embodiment is based on the embodiment 1. The difference between this embodiment and the embodiment 1 is that the water retaining agent in this embodiment is a polyvinyl alcohol type water retaining agent; the rest of the parts are the same as the embodiment 1.

[0085] Example 6

[0086] This embodiment is based on the embodiment 1. The difference between this embodiment and the embodiment 1 is that the water retaining agent in this embodiment is a polyacrylamide type water retaining agent; the rest of the parts are the same as the embodiment 1.

[0087] Example 7

[0088] This embodiment is based on the embodiment 1, and the difference between this embodiment and the embodiment 1 is: S1, a fertilizer pit 1 with a depth of 40 cm is dug in the field ditch on one side of the citrus fruit tree planting area, and the horizontal straight-line distance between the location of the fertilizer pit 1 and the surrounding citrus fruit trees is 0.6m; the citrus fruit trees are fruit trees over 1 year old excluding 1 year and within 3 years including 3 years.

[0089] Comparative Example 1

[0090] The difference from Example 1 is that this comparative example does not use component A and component B to treat the inner wall of the bamboo tube, and the rest is the same as Example 1.

[0091] Comparative Example 2

[0092] Different from Example 1, in this comparative example, component A is not used to treat the inner wall of the bamboo tube, and component B is directly sprayed on the inner wall of the bamboo tube to form a thin film.

[0093] Comparative Example 3

[0094] Different from Example 1, in this comparative example, component B is not used to treat the inner wall of the bamboo tube, and component A is directly sprayed on the inner wall of the bamboo tube to form a thin film.

[0095] Comparative Example 4

[0096] Different from Example 1, no polysaccharide-peptide conjugate is added to component A in this comparative example.

[0097] Comparative Example 5

[0098] Different from Example 1, in this comparative example, component A does not contain macromolecular tannic acid or metal ion complex.

[0099] Comparative Example 6

[0100] Different from Example 1, in this comparative example, the linear low-density polyethylene is not modified by plant fiber in component B, and component B is a linear low-density polyethylene film.

[0101] Comparative Example 7

[0102] In this comparative example, the same amount of liquid fertilizer as in Example 1 is directly poured into the fertilizer pit and then covered with soil. No bamboo tube is used, and no water retaining agent and organic copper are added to the liquid fertilizer; no bamboo tube is used to hold the liquid fertilizer.

[0103] Test Example 1

[0104] The bamboo tubes in Examples 1-7 and Comparative Examples 1-3 were filled with liquid fertilizer (the one containing organic copper and water retaining agent was liquid fertilizer containing organic copper and water retaining agent), and the bamboo tubes with a length of 30 cm and a diameter of 10 cm had a volume of about 2.3 liters; a bamboo tube was placed in a fertilizer pit, and the concentration changes of nitrogen, phosphorus and potassium in the soil in the fertilizer pits of Examples 1-7 and Comparative Examples 1-3 and 7 were measured; the changes of nitrogen, phosphorus and potassium in the soil in Examples 1-7 over time were that the nitrogen, phosphorus and potassium in the soil were slowly increasing within a period of time (within one month), and slowly decreasing after one month, and were in equilibrium after decreasing to a certain concentration, and the equilibrium stage could be maintained for 2-3 months (2-3 The bamboo tube continuously releases fertilizer within one month), and when the fertilizer inside the bamboo tube is released, the nitrogen, phosphorus and potassium concentrations in the soil slowly decrease; the highest concentrations of nitrogen, phosphorus and potassium in the soil in Comparative Examples 1, 2 and 3 are all lower than the highest concentrations of nitrogen, phosphorus and potassium in the soil in Examples 1-7; the nitrogen, phosphorus and potassium concentrations in the soil in Comparative Example 7 reach the highest concentration within 24 hours, and the highest concentration is greater than the highest concentrations of nitrogen, phosphorus and potassium in the soil in Examples 1-7, and the nitrogen, phosphorus and potassium concentrations in the soil in Comparative Example 7 reach the highest concentration and then decrease rapidly after one month, and the nitrogen, phosphorus and potassium concentrations one month away from the maximum concentration are lower than the concentrations when the nitrogen, phosphorus and potassium concentrations in the soil in Examples 1-7 maintain equilibrium. It is enough to show that the present invention has the function of slow-release fertilizer fertilization.

[0105] Test Example 2

[0106] Determine the loss rate of nitrogen, phosphorus and potassium in the water-soluble compound fertilizers of nitrogen, phosphorus and potassium in the bamboo tubes in Example 1 and Comparative Examples 1-6 within 48 hours;

[0107] Equal amounts of water-soluble compound fertilizers were respectively placed in the bamboo tubes of Example 1 and Comparative Examples 1-6. The bamboo tubes were sealed and placed in the same environment (room temperature). The initial concentrations C1 of nitrogen, phosphorus and potassium in the bamboo tubes were first determined. After 72 hours, the concentrations C2 of nitrogen, phosphorus and potassium in the bamboo tubes were determined. The loss rate was calculated based on the changes in the two concentrations. Loss rate = (C1-C2) / C1. The results are shown in Table 1.

[0108] Table 1 Loss rate of active ingredients

[0109] Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Nitrogen loss rate 0 1.2％ 0.05％ 0.13％ 0.02％ 0.9％ 0.01％ Phosphorus loss rate 0 0.83％ 0.01％ 0.08％ 0 0.58％ 0 Potassium loss rate 0 0.77％ 0.02％ 0.09％ 0.01％ 0.49％ 0

[0110] As shown in Table 1, after the inner wall of the bamboo tube of the present invention is treated with component A and component B, the effective components in the fertilizer can be prevented from being adsorbed by the inner wall of the bamboo tube, thereby effectively avoiding the loss of the effective components of the fertilizer.

[0111] Test Example 3

[0112] Determine the stickiness of the film on the inner wall of the bamboo tube in Example 1 and Comparative Examples 2-6;

[0113] Hydrochloric acid with a mass fraction of 5% and sodium hydroxide with a mass fraction of 10% were used as the detection liquid; the inner wall of the bamboo tube was treated according to the method in Example 1 and Comparative Examples 2-6, and two bamboo tubes were obtained by corresponding treatment for each preparation method, one bamboo tube was used to hold hydrochloric acid, and the other bamboo tube was used to hold sodium hydroxide. After the inside of the bamboo tube was in a closed environment, the peeling degree of the film on the inner wall of the bamboo tube after being soaked in acid and alkali for 30 days was detected. The film with good adhesion would not peel at all, and the film with poor adhesion would peel, bubble, and fall off; the test results are shown in Table 2.

[0114] Table 2 Adhesion test results

[0115] Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Acid Soaking No peeling Partially fallen off Foaming Warping Partially fallen off No peeling Alkali soaking No peeling Partially fallen off No peeling Foaming Partially fallen off No peeling

[0116] As shown in Table 2, the film formed by the synergistic effect between component A and component B of the present invention has good acid and alkali resistance and can be applied to fertilizers with different pH values.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made by any technician familiar with the field within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A slow-release citrus planting fertilization process, characterized in that: The following steps are involved: S1. Dig a fertilizer pit (1) with a depth of 35-40 cm in the field ditch on one side of the citrus tree planting area, and the horizontal straight-line distance between the location of the fertilizer pit (1) and the surrounding citrus trees is 0.6-1 m; S2. Obtain a plurality of bamboo tubes (2) each 30 cm long, wherein the top of each bamboo tube (2) is completely open, each bamboo tube (1) has a bamboo node at its lower end, each bamboo node at the lower end of each bamboo tube (1) is provided with a through hole (21) connected to the interior of the bamboo tube (2), and each through hole (21) is blocked by a soft plug; S3, liquid fertilizer, water retaining agent and organic copper are placed inside the bamboo tube (2) in step S2, and then the opening at the top of the bamboo tube (2) is sealed with a bamboo tube cover (22), and then the soft plug of the through hole (21) is pulled out to open the through hole (21) on the bamboo node at the lower end of the bamboo tube (1), and then the bamboo tube (2) is placed in the fertilizer pit (1), and a plurality of bamboo tubes filled with liquid fertilizer, water retaining agent and organic copper are placed in each fertilizer pit (1).

2. A slow-release citrus planting fertilization process according to claim 1, characterized in that: Step S2 also includes the following steps: coating the inner wall of the bamboo tube (2) with a treatment agent, wherein the treatment agent includes component A and component B; The component A comprises the following components: macromolecular tannic acid, metal ions, and polysaccharide-peptide conjugates; wherein the mass ratio of macromolecular tannic acid, metal ions, and polysaccharide-peptide conjugates is 1:1:3.5; The component B is a plant fiber modified polyethylene degradable film; The processing method is: S2.1 Preparation of component A: Dissolve macromolecular tannic acid and metal ions in deionized water to obtain macromolecular tannic acid solution and metal ion solution respectively, then evenly mix the macromolecular tannic acid solution and metal ion solution and stir to react at 40°C, continue to stir to react for 1 hour, add polysaccharide-peptide conjugate, heat to 50°C, continue to stir to react at 50°C for 1.5 hours, and obtain component A; S2.2 Preliminary treatment of the inner wall of the bamboo tube: spray component A evenly on the inner wall of the bamboo tube, perform UV curing on the inner wall of the bamboo tube, and obtain a semi-cured adhesive layer after curing for 10 minutes; S2.3 Preparation of component B: obtaining long-fiber wood pulp, long-fiber hemp pulp, and long-fiber sedge pulp, uniformly mixing the long-fiber wood pulp, long-fiber hemp pulp, and long-fiber sedge pulp to obtain plant fiber pulp, selecting linear low-density polyethylene as a substrate, heating the linear low-density polyethylene to a molten state, and then mixing the plant fiber pulp with the linear low-density polyethylene in a molten state, and adding a curing agent to form a uniform melt; then uniformly spraying the melt on the semi-solidified adhesive layer on the inner wall of the bamboo tube that has been preliminarily treated in step S2.2, heating and curing at 90-100°C, forming a plant fiber modified polyethylene degradable film on the adhesive layer, the adhesive layer and the plant fiber modified polyethylene degradable film are completely cured, and the adhesive layer is tightly connected to the plant fiber modified polyethylene film and the inner wall of the bamboo tube. The bamboo tube used for holding liquid fertilizer, water-retaining agent and organic copper in step S3 is a bamboo tube whose inner wall has been treated with component A and component B.

3. The slow-release citrus planting fertilization process according to claim 1, characterized in that: The metal ions are magnesium ions or calcium ions or a mixture of the two.

4. A slow-release citrus planting fertilization process according to claim 3, characterized in that: The metal ions are a mixture of magnesium ions and calcium ions, and the mass ratio of the magnesium ions to the calcium ions is 1:

1.

5. The slow-release citrus planting fertilization process according to claim 2, characterized in that: In the step S2.3, the mass ratio of long fiber wood pulp, long fiber hemp pulp, and long fiber sedge pulp is 1:1.5:1.

2.

6. A slow-release citrus planting fertilization process according to claim 2, characterized in that: The preparation method of the polysaccharide-peptide conjugate comprises the following steps: dissolving carboxylated seaweed polysaccharide in a phosphate buffer, adjusting the pH to 7.4, and obtaining a carboxylated seaweed polysaccharide solution; dissolving arginine polypeptide and lysine polypeptide in a phosphate buffer, and obtaining a mixed solution of arginine polypeptide and lysine polypeptide; respectively preparing a 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide solution and an N-hydroxysuccinimide solution; adding the 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide solution to the carboxylated seaweed polysaccharide solution under stirring conditions, reacting at room temperature for 30 minutes, then adding the N-hydroxysuccinimide solution, continuing to stir and react for 15 minutes, then slowly adding the mixed solution of arginine polypeptide and lysine polypeptide, stirring and reacting at 30°C for 12 hours, finally adding glycine to terminate the reaction, and purifying to obtain the polysaccharide-peptide conjugate.

7. A slow-release citrus planting fertilization process according to claim 6, characterized in that: The carboxylated seaweed polysaccharide is prepared by the following method: dissolving seaweed polysaccharide in water to obtain a seaweed polysaccharide solution, then adding succinic anhydride and acetic acid to the seaweed polysaccharide solution under stirring conditions, continuing stirring and reacting at 25-30° C. for 20 hours, and finally purifying, drying and dehydrating to obtain the carboxylated seaweed polysaccharide.

8. The slow-release citrus planting fertilization process according to claim 1, characterized in that: The bamboo tube cover (22) is a hollow cylindrical cover with an open bottom that matches the shape of the bamboo tube (1). The bamboo tube cover (22) is threadedly connected to the top of the bamboo tube (1).

9. The slow-release citrus planting fertilization process according to claim 1, characterized in that: The liquid fertilizer includes at least one of a water-soluble compound fertilizer containing nitrogen, phosphorus and potassium, an amino acid water-soluble fertilizer and a humic acid water-soluble fertilizer.

10. The slow-release citrus planting fertilization process according to claim 1, characterized in that: The water retaining agent is one of bentonite grafted potassium humate, starch-polyacrylamide type water retaining agent, polyvinyl alcohol type water retaining agent and polyacrylamide type water retaining agent.

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