Slow-release organic-inorganic composite liquid fertilizer and its drip irrigation special proportioning process

Abstract

The application provides a slow-release organic-inorganic composite liquid fertilizer and a special proportioning process thereof for drip irrigation, and belongs to the technical fields of liquid fertilizer preparation and water-fertilizer integrated drip irrigation fertilization. The application comprises the following steps: sequentially performing directional activation modification of a multi-source organic matrix, preparation of inorganic nutrient grading differentiation dissolution, gradient composite high-shear slow-release gelation reaction, constant-temperature precise pH curing and shaping, and growth period grading adaptive drip irrigation proportioning, and completing the proportioning of the slow-release organic-inorganic composite liquid fertilizer. The application overcomes the defects in the prior art, such as easy flocculation and precipitation of the liquid fertilizer, poor storage stability, concentrated nutrient release, short fertilizer efficiency period, easy pipe blockage during drip irrigation, and incapability of adapting to the nutrient requirements of crops in the whole growth period, and achieves the technical effects of high stability, gradient slow release, low blockage rate and whole growth period adaptation of the product.

Description

Technical Field

[0001] This invention provides a slow-release organic-inorganic compound liquid fertilizer and its drip irrigation-specific formulation process, belonging to the field of liquid fertilizer preparation and integrated water and fertilizer drip irrigation fertilization technology. Background Technology

[0002] With the popularization of modern agricultural fertigation technology, drip irrigation fertilization has become the mainstream fertilization method in facility agriculture and large-scale field planting due to its advantages of water conservation, fertilizer conservation, labor saving, and high efficiency. Existing commercial organic and inorganic liquid fertilizers mainly suffer from the following common industry defects: First, traditional liquid fertilizers often use a one-step direct mixing process, where organic raw materials are directly mixed with high-concentration inorganic salts. This can easily lead to ion antagonism, colloidal flocculation, and system precipitation and stratification, resulting in poor product storage stability. At room temperature, the product is prone to bottom clumping and upper clear liquid, resulting in a short shelf life.

[0003] Secondly, conventional liquid fertilizers are mostly fast-acting release systems, with concentrated nutrient release and short-term fertilizer effect. In the early stage, excessive nutrients can easily lead to leaching and soil salinization, while in the later stage, nutrient deficiency can lead to premature aging of crops and a decline in yield and quality. They cannot match the gradient nutrient requirements of crops throughout their entire growth period.

[0004] Third, existing drip irrigation liquid fertilizers have crude processes for particle size control, system viscosity, and impurity filtration. Fine particles and agglomerated colloids in the system can easily clog the micropores of the drip irrigation tape and the flow channels of the drippers, causing uneven drip irrigation and localized drought. This seriously affects the stability of the integrated water and fertilizer system and is the core pain point that currently restricts the large-scale promotion of liquid fertilizers.

[0005] Fourth, existing technologies focus more on improving formulation components, and there is insufficient research on complete processes for graded dissolution, gradient compounding, in-situ construction of slow-release structures, and differentiated ratios for different growth periods to adapt to drip irrigation conditions. This results in products that are either stable but lack slow-release properties, or have slow-release properties but poor flowability and are prone to clogging, making it difficult to achieve both long-lasting slow release and drip irrigation compatibility.

[0006] Therefore, developing a process for preparing organic-inorganic compound liquid fertilizer that is controllable, has strong system stability, possesses gradient slow-release function, is fully compatible with drip irrigation systems, and can meet the fertilization needs of crops throughout their entire growth period has significant production application value and market prospects. Summary of the Invention

[0007] This invention aims to overcome the shortcomings of existing liquid fertilizers, such as easy flocculation and sedimentation, poor storage stability, concentrated nutrient release, short fertilizer effect period, easy pipe clogging in drip irrigation, and inability to adapt to the nutrient needs of crops throughout their entire growth period. It provides a slow-release organic-inorganic compound liquid fertilizer and its drip irrigation-specific formulation process. This invention achieves high product stability, gradient slow release, low clogging rate, and adaptability to the entire crop growth period through a complete set of improved processes including organic-directed activation, inorganic graded differentiated dissolution, gradient compound emulsification, constant-temperature maturation and shaping, and graded formulation for different growth periods.

[0008] To address the aforementioned problems, the present invention proposes the following technical solution: a slow-release organic-inorganic compound liquid fertilizer and its drip irrigation-specific formulation process, comprising the following steps: S1. Targeted Activation and Modification of Multi-Source Organic Matrix: A mixed organic liquid is prepared by compounding highly active humic acid stock solution, plant compound amino acid solution, and seaweed polysaccharide stock solution in a mass ratio of (40-60):(25-35):(5-15). A composite organic chelating activator is added to the mixed organic liquid, and the reaction is carried out for 15-25 minutes under low-speed stirring at 80-120 r / min at room temperature to complete the chain scission activation of organic macromolecules and the modification of colloidal stability, remove native insoluble impurities and easily flocculated gels in the system, and obtain a highly stable modified organic mother liquor; the composite organic chelating activator is prepared by compounding citric acid and potassium lactate in a mass ratio of (3-5):1, and its addition amount is 1.2%-2.5% of the total mass of the mixed organic liquid; S2. Differentiated dissolution preparation of inorganic nutrients: A two-stage differentiated dissolution process is used to treat water-soluble fast-acting inorganic nutrients, ammonium polyphosphate slow-release inorganic nutrients, and EDTA chelated trace elements. The first stage is room temperature dissolution: at 20-25℃, urea ammonium nitrate and potassium sulfate fast-acting components are dissolved in deionized water and stirred for 10-15 min until the system is completely clear. The second stage is constant temperature activation dissolution: at a constant temperature of 40-50℃, the ammonium polyphosphate slow-release component and EDTA chelated trace elements are dispersed and dissolved, and stirred for 15-20 min to complete the activation and dispersion of the slow-release nutrients, controlling the particle size of the inorganic solution solid phase particles to be ≤5μm. The mass ratio of the fast-acting inorganic nutrients, slow-release inorganic nutrients, and chelated trace elements is (35-45):(12-18):(3-8). S3, Gradient Composite High-Shear Sustained-Release Gel-Forming Reaction: The modified organic mother liquor prepared in S1 is pumped into a closed emulsification reactor and preheated to 35-45℃. The inorganic nutrient solution prepared in S2 is added dropwise at a low speed with stirring, and the dropwise addition time is controlled to be 40-60 min to achieve gradient fusion of the organic and inorganic phases. After the dropwise addition is completed, magnesium aluminum silicate-nonionic polyacrylamide composite suspension stabilizer and sulfonated lignin gel sustained-release agent are added. The high-shear emulsification mode of 2800-3200 r / min is switched, and emulsification is carried out for 20-30 min to construct an organic-inorganic cross-linked three-dimensional network sustained-release structure in situ, resulting in a uniform and stable composite suspension system. S4. Constant Temperature and Precise pH Maturation and Shaping: The emulsified compound liquid is transferred to a sealed, light-proof maturation tank and matured for 18-24 hours at a constant temperature of 25-30℃ and a stirring speed of 60-80r / min. During the maturation process, the pH of the system is monitored in real time, and a phosphoric acid-potassium hydroxide weak buffer system is used for micro-adjustment to stabilize the pH of the system at 5.5-7.0, solidifying the three-dimensional network slow-release structure and obtaining the initial slow-release compound liquid fertilizer. S5. Drip irrigation ratio adapted to different growth stages: Based on the nutrient requirements of crops at different growth stages, differentiated liquid-water dilution ratios are adopted: seedling stage dilution ratio 1:(800-1000), growth stage dilution ratio 1:(500-700), and fruit expansion stage dilution ratio 1:(300-400). After dilution, the solution is filtered through a two-stage process of 100-mesh coarse filtration and 200-mesh fine filtration to remove trace agglomerates, thus producing a drip irrigation-specific slow-release organic-inorganic compound liquid fertilizer.

[0009] Furthermore, in step S1, the humic acid stock solution has a mass concentration of 45%-55% and an effective humic acid content of ≥35%; the plant compound amino acid solution has a total free amino acid and polypeptide content of ≥120g / L; the seaweed polysaccharide solution has an active polysaccharide content of ≥30g / L; the modified organic mother liquor has no stratification or precipitation after standing at room temperature for 72h, and the flocculation rate of the system is ≤0.5%.

[0010] Furthermore, in step S2, the trace elements chelated by EDTA are a composite system of chelated calcium, chelated magnesium, chelated iron, chelated zinc, and chelated boron, and are all prepared using chelated raw materials.

[0011] Furthermore, in step S3, the mass ratio of magnesium aluminum silicate to nonionic polyacrylamide is (8-12):1, the amount of compound suspension stabilizer added is 0.8%-1.5% of the total mass of the composite system, and the amount of sulfonated lignin gel slow-release additive added is 1.0%-2.0% of the total mass of the composite system.

[0012] Furthermore, in step S4, pH adjustment is carried out by adding small amounts multiple times, with the amount of the regulator added at one time not exceeding 0.1% of the total mass of the system; after maturation and shaping, the viscosity of the compound liquid fertilizer is 15-25 mPa·s.

[0013] Furthermore, in step S5, the maximum particle size of the liquid fertilizer after two-stage filtration is ≤2μm.

[0014] Furthermore, the slow-release organic-inorganic compound liquid fertilizer, by mass percentage, comprises the following raw material components: 38%-48% modified organic mother liquor, 25%-35% fast-acting inorganic nutrients, 10%-15% slow-release inorganic nutrients from ammonium polyphosphate, 3%-8% EDTA-chelated trace elements, 1.0%-2.0% sulfonated lignin gel slow-release adjuvant, 0.8%-1.5% magnesium aluminum silicate compound suspension stabilizer, and the balance being deionized water.

[0015] Furthermore, the liquid fertilizer exhibits no stratification, demulsification, or precipitation after 90 days of sealed storage at room temperature; the initial nutrient release rate is ≤25% from 0-15 days, the stable nutrient release rate is 60%-70% from 15-60 days, and the residual slow-release nutrients are ≥15% after 60 days.

[0016] Furthermore, the liquid fertilizer is suitable for soil environments with a pH of 5.0-8.5 and is used for drip irrigation fertilization of crops.

[0017] Due to the adoption of the above technical solution, the beneficial effects of the slow-release organic-inorganic compound liquid fertilizer and its drip irrigation-specific formulation process of this invention are as follows: 1. Strong process innovation, solving the problem of system instability from the root: This invention abandons the traditional one-step mixing process and adopts a coupled process of organic directional activation + inorganic graded dissolution + gradient composite emulsification. First, the organic macromolecules are modified by chain breaking and the easily flocculated groups are eliminated. Then, the fast-acting and slow-release inorganic components are graded and dissolved to avoid the instantaneous and violent antagonism between organic and inorganic components. The system stability is greatly improved. There is no stratification, precipitation and demulsification after 90 days of sealed storage at room temperature.

[0018] 2. Construct a controllable three-dimensional slow-release structure to achieve gradient nutrient release: Through the in-situ formation of an organic-inorganic cross-linked network structure by sulfonated lignin and magnesium aluminum silicate compound system, the nutrients are released slowly in the early stage, steadily in the middle stage, and continuously in the later stage, solving the problems of seedling burn in the early stage and nutrient deficiency in the later stage of traditional liquid fertilizers. The fertilizer effect period is extended to more than 60 days, which conforms to the growth pattern of plants.

[0019] 3. Perfectly compatible with drip irrigation systems, completely solving the problem of pipe blockage: Through graded particle size control, high shear homogenization, and two-stage precision filtration, the maximum particle size of the product is ≤2μm, with moderate viscosity and excellent flowability. It can be used for long-term continuous drip irrigation without micropore blockage or pipe scaling, and is compatible with various commercial drip irrigation equipment.

[0020] 4. Precise dilution ratio during the growth period significantly improves fertilizer utilization: Differentiated dilution ratios for the seedling, growth, and fruit expansion stages avoid nutrient waste or insufficient supply caused by single-concentration fertilization, significantly improving water and fertilizer utilization efficiency. At the same time, it can improve soil aggregate structure and alleviate soil compaction and salinization. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart illustrating the overall preparation process of the slow-release organic-inorganic compound liquid fertilizer and its drip irrigation-specific formulation process of the present invention.

[0022] Figure 2 This is a schematic diagram of the organic-inorganic cross-linked three-dimensional network slow-release structure of the slow-release organic-inorganic composite liquid fertilizer and its drip irrigation-specific formulation process of the present invention.

[0023] Figure 3 This is a comparison curve of nutrient release cycle for three sets of embodiments of the slow-release organic-inorganic compound liquid fertilizer and its drip irrigation-specific formulation process of the present invention.

[0024] Figure 4 The images show a comparison of the storage stability of three sets of embodiments of the slow-release organic-inorganic compound liquid fertilizer and its drip irrigation-specific formulation process of the present invention.

[0025] Figure 5 This is a bar chart comparing the effects of different growth stages on the dilution adaptation of the slow-release organic-inorganic compound liquid fertilizer of this invention and its drip irrigation-specific formulation process, as well as the crop yield increase. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1 A slow-release organic-inorganic compound liquid fertilizer, by mass percentage, comprises: 42% modified organic mother liquor, 30% fast-acting inorganic nutrients, 12% slow-release inorganic nutrients from ammonium polyphosphate, 5% EDTA chelated trace elements, 1.5% sulfonated lignin gel slow-release adjuvant, 1.2% magnesium aluminum silicate compound suspension stabilizer, and 8.3% deionized water.

[0028] The specific mixing process steps for drip irrigation in this embodiment are as follows: S1. Targeted activation and modification of multi-source organic matrix: A humic acid stock solution with a concentration of 50% and an effective humic acid content of 38%, a plant-based compound amino acid solution with an amino acid and polypeptide content of 125 g / L, and an algae polysaccharide stock solution with an active polysaccharide content of 32 g / L were mixed in a mass ratio of 50:30:10. A compound chelating activator (citric acid: potassium lactate = 4:1) was added to the total mass of the mixed organic solution. The mixture was stirred at 100 r / min for 20 min at room temperature to obtain a modified organic mother liquor. After standing at room temperature for 72 h, no stratification occurred, and the flocculation rate was 0.35%.

[0029] S2. Differentiated dissolution preparation of inorganic nutrients: The mass ratio of fast-acting inorganic nutrients, slow-release inorganic nutrients, and chelated trace elements is 40:15:5; in the first stage, urea ammonium nitrate and potassium sulfate are dissolved at room temperature of 22℃ and stirred for 12 min until clear; in the second stage, ammonium polyphosphate is dissolved at a constant temperature of 45℃ and chelated with calcium, magnesium, iron, zinc, and boron complex trace elements with EDTA and stirred for 18 min, with the solid phase particle size of the inorganic solution ≤5μm.

[0030] S3. Gradient composite high-shear slow-release gelation reaction: The modified organic mother liquor is preheated to 40℃, and the inorganic nutrient solution is added dropwise at a uniform rate for 50 min; a compound stabilizer (magnesium aluminum silicate: nonionic polyacrylamide = 10:1, addition amount 1.2%) and sulfonated lignin slow-release adjuvant (addition amount 1.5%) are added, and high-shear emulsification is carried out at 3000 r / min for 25 min to form a stable cross-linked network system.

[0031] S4. Constant temperature and precise pH curing and shaping: Curing at 28℃ and 70r / min in the dark for 20h, using a phosphoric acid-potassium hydroxide buffer system to adjust the pH to 6.2 in small amounts, with a single addition amount ≤0.1%, and the finished product viscosity is 20mPa•s.

[0032] S5. Drip irrigation ratio adapted to different growth stages: 1:900 dilution during seedling stage, 1:600 ​​dilution during growth stage, and 1:350 dilution during fruit expansion stage. After two-stage filtration (100 mesh + 200 mesh), the maximum particle size of the finished product is ≤2μm.

[0033] Performance testing: No delamination or emulsion breaking after 90 days of sealed storage at room temperature; nutrient release rate of 22.3% from 0-15 days, stable release rate of 65.8% from 15-60 days, residual nutrient content of 16.7% after 60 days, suitable for drip irrigation application in soil with pH 5.0-8.5.

[0034] Example 2 A slow-release organic-inorganic compound liquid fertilizer, by mass percentage, comprises: 38% modified organic mother liquor, 35% fast-acting inorganic nutrients, 10% slow-release inorganic nutrients from ammonium polyphosphate, 8% EDTA chelated trace elements, 2.0% sulfonated lignin gel slow-release adjuvant, 1.5% magnesium aluminum silicate compound suspension stabilizer, and 5.5% deionized water.

[0035] The specific mixing process steps for drip irrigation in this embodiment are as follows: S1. Targeted activation and modification of multi-source organic matrix: A humic acid stock solution with a concentration of 45% and an effective humic acid content of 35%, a plant-based compound amino acid solution with an amino acid and polypeptide content of 120 g / L, and an algae polysaccharide stock solution with an active polysaccharide content of 30 g / L were mixed in a mass ratio of 40:35:15. A compound chelating activator (citric acid: potassium lactate = 3:1) was added to the total mass of the mixed organic solution. The mixture was stirred at room temperature and 80 r / min for 25 min to obtain a modified organic mother liquor. After standing at room temperature for 72 h, no stratification occurred, and the flocculation rate was 0.42%.

[0036] S2. Differentiated dissolution preparation of inorganic nutrients: The mass ratio of fast-acting inorganic nutrients, slow-release inorganic nutrients, and chelated trace elements is 35:18:8; in the first stage, the fast-acting component is dissolved at room temperature of 20℃ and stirred for 15 min until clear; in the second stage, the slow-release component and chelated trace elements are dissolved at constant temperature of 40℃ and stirred for 20 min, with the solid phase particle size of the inorganic solution ≤5μm.

[0037] S3. Gradient composite high-shear slow-release gelation reaction: The modified organic mother liquor is preheated to 35℃, and the inorganic nutrient solution is added dropwise at a uniform rate for 60 min; a compound stabilizer (magnesium aluminum silicate: nonionic polyacrylamide = 8:1, addition amount 1.5%) and sulfonated lignin slow-release adjuvant (addition amount 2.0%) are added, and high-shear emulsification is carried out at 2800 r / min for 30 min to form a stable cross-linked network system.

[0038] S4. Constant temperature and precise pH maturation and shaping: Mature at 25℃ and 60r / min in the dark for 24 hours, adjust the pH of the buffer system to 5.5, add ≤0.1% at a time, and the viscosity of the finished product is 15mPa•s.

[0039] S5. Drip irrigation ratio adapted to different growth stages: 1:800 dilution during seedling stage, 1:500 dilution during growth stage, and 1:300 dilution during fruit expansion stage. After two-stage filtration, the maximum particle size of the finished product is ≤2μm.

[0040] Performance testing: No stratification or demulsification after 90 days of sealed storage at room temperature; nutrient release rate of 24.1% from 0-15 days, stable release rate of 62.5% from 15-60 days, and residual nutrient content of 15.2% after 60 days, suitable for broad-spectrum soil drip irrigation fertilization.

[0041] Example 3 A slow-release organic-inorganic compound liquid fertilizer, by mass percentage, comprises: 48% modified organic mother liquor, 25% fast-acting inorganic nutrients, 15% slow-release inorganic nutrients from ammonium polyphosphate, 3% EDTA chelated trace elements, 1.0% sulfonated lignin gel slow-release adjuvant, 0.8% magnesium aluminum silicate compound suspension stabilizer, and 7.2% deionized water.

[0042] The specific mixing process steps for drip irrigation in this embodiment are as follows: S1. Targeted activation and modification of multi-source organic matrix: A mixed organic liquid was prepared by mixing 55% humic acid stock solution with 40% effective humic acid content, plant compound amino acid solution with 130 g / L amino acid and polypeptide content, and seaweed polysaccharide stock solution with 35 g / L active polysaccharide content at a mass ratio of 60:25:5; 1.2% of the total mass of the mixed organic liquid was added with a compound chelating activator (citric acid: potassium lactate = 5:1), and the mixture was stirred at room temperature and 120 r / min for 15 min to obtain a modified organic mother liquor. After standing at room temperature for 72 h, no stratification occurred and the flocculation rate was 0.28%.

[0043] S2. Differentiated dissolution preparation of inorganic nutrients: The mass ratio of fast-acting inorganic nutrients, slow-release inorganic nutrients, and chelated trace elements is 45:12:3; in the first stage, the fast-acting component is dissolved at room temperature of 25℃ and stirred for 10 min until clear; in the second stage, the slow-release component and chelated trace elements are dissolved at constant temperature of 50℃ and stirred for 15 min, with the solid phase particle size of the inorganic solution ≤5μm.

[0044] S3. Gradient composite high-shear slow-release gelation reaction: The modified organic mother liquor is preheated to 45℃, and the inorganic nutrient solution is added dropwise at a uniform rate for 40 min; a compound stabilizer (magnesium aluminum silicate: nonionic polyacrylamide = 12:1, addition amount 0.8%) and sulfonated lignin slow-release adjuvant (addition amount 1.0%) are added, and high-shear emulsification is carried out at 3200 r / min for 20 min to form a stable cross-linked network system.

[0045] S4. Constant temperature and precise pH maturation and shaping: Mature at 30℃ and 80r / min in the dark for 18 hours, adjust the pH of the buffer system to 7.0, add ≤0.1% at a time, and the viscosity of the finished product is 25mPa•s.

[0046] S5. Drip irrigation ratio adapted to different growth stages: 1:1000 dilution during seedling stage, 1:700 dilution during growth stage, and 1:400 dilution during fruit expansion stage. The maximum particle size of the finished product after two-stage filtration is ≤2μm.

[0047] Performance testing: No stratification or demulsification after 90 days of sealed storage at room temperature; nutrient release rate of 21.5% from 0-15 days, stable release rate of 68.2% from 15-60 days, and residual nutrient content of 18.1% after 60 days. It has the best slow-release effect and is suitable for application on long-growing crops.

[0048] Comparison of Implementation Examples and Summary of Results Based on the parameter range defined in the claims, the three sets of embodiments of this invention employ gradient-differentiated formulation and process parameter design, respectively corresponding to three application scenarios: balanced general application, high nutrient supply, and long-acting sustained release. A detailed comparison and summary of the parameter differences, performance characteristics, and suitable scenarios for each set of embodiments is summarized below: Comparison of formulation components: Example 1 is a balanced formulation with a moderate ratio of modified organic mother liquor, fast-acting nutrients, slow-release nutrients, and micronutrients, and the synergistic effect of each component is optimal, making it a general-purpose formulation; Example 2 focuses on the supplementation of inorganic nutrients and micronutrients, significantly increasing the amount of fast-acting inorganic nutrients (35%) and EDTA-chelated micronutrients (8%), while reducing the proportion of organic mother liquor and slow-release nutrients, which can quickly supplement crops with nutrients and solve the problems of crop nutrient deficiency and weak growth; Example 3 focuses on the ratio of organic matrix and slow-release nutrients, maximizing the amount of modified organic mother liquor (48%) and ammonium polyphosphate slow-release nutrients (15%), reducing the proportion of fast-acting nutrients, and showing outstanding organic improvement ability and long-term slow-release performance.

[0049] Comparison of different preparation process parameters: The three sets of examples strictly adhere to the process range of this invention, forming a gradient of parameter differences. Example 1 uses median process parameters, with stirring speed, reaction temperature, dropping time, and maturation time all being the median values ​​of the range, resulting in high process stability and good tolerance. Example 2 uses a low-temperature, long-time maturation, and high-stabilizer addition process, with a lower emulsification speed and a longer maturation time, combined with the highest proportion of suspension stabilizer and slow-release adjuvant, resulting in excellent system suspension stability and suitability for complex water and fertilizer environments. Example 3 uses a high-temperature, short-time emulsification, and high-shear speed process, with the highest reaction temperature and shear speed fully activating the organic matrix and slow-release nutrients, maximizing the construction of a dense three-dimensional network slow-release structure, providing process support for long-term slow-release effects.

[0050] Product performance differentiation comparison: In terms of storage stability, all three sets of examples met the standard of no stratification, demulsification, or precipitation after 90 days. Among them, Example 3 had the lowest flocculation rate (0.28%) and the best colloidal stability of the system. In terms of nutrient release performance, Example 2 had the highest initial nutrient release rate (24.1%) and the strongest rapid effect, which can quickly meet the emergency fertilization needs of crops. Example 3 had the lowest initial release rate (21.5%) and the highest residual nutrient in the later stage (18.1%), with a longer slow release period and more balanced nutrient release. Example 1 had moderate release indicators and balanced rapid and slow release performance. In terms of physical indicators, Example 1 had moderate viscosity, the best drip irrigation flowability, and was not easy to clog the pipe network. Example 2 had the lowest viscosity and stronger dilution and penetration ability. Example 3 had the highest viscosity and a more stable network structure of the system.

[0051] Summary of Scenario Adaptation: Example 1 is a general-purpose type, suitable for conventional drip irrigation fertilization of most fruits, vegetables, and cash crops throughout their entire growth period. It has wide applicability and high overall cost-effectiveness. Example 2 is a fast-acting nutrient supplement type, suitable for scenarios such as strengthening weak seedlings in the seedling stage, correcting nutrient deficiencies during the growth period, and short-term rapid topdressing, which can quickly improve crop growth status. Example 3 is a long-lasting improvement type, suitable for long-growing-period crops such as fruit trees and seedlings. It can also improve soil physicochemical properties over a long period, adapting to the continuous fertilization needs of barren soils and continuously cropped soils. The three sets of examples fully verify the adjustability and adaptability of the formula and process of this invention. It can accurately match fertilization schemes according to crop varieties, growth stages, and soil conditions. Compared with traditional single liquid fertilizers, the targeting of fertilization, nutrient utilization rate, and soil adaptability are all significantly improved.

[0052] The present invention and its embodiments have been described above. This description is not restrictive. In short, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the spirit of the present invention, such design should fall within the protection scope of the present invention.

Claims

1. A drip irrigation-specific formulation process for slow-release organic-inorganic compound liquid fertilizer, characterized in that, Includes the following steps: S1. Targeted Activation and Modification of Multi-Source Organic Matrix: A mixed organic liquid is prepared by compounding highly active humic acid stock solution, plant compound amino acid solution, and seaweed polysaccharide stock solution in a mass ratio of (40-60):(25-35):(5-15). A composite organic chelating activator is added to the mixed organic liquid, and the reaction is carried out for 15-25 minutes under low-speed stirring at 80-120 r / min at room temperature to complete the chain scission activation of organic macromolecules and the modification of colloidal stability, remove native insoluble impurities and easily flocculated gels in the system, and obtain a highly stable modified organic mother liquor; the composite organic chelating activator is prepared by compounding citric acid and potassium lactate in a mass ratio of (3-5):1, and its addition amount is 1.2%-2.5% of the total mass of the mixed organic liquid; S2. Differentiated dissolution preparation of inorganic nutrients: A two-stage differentiated dissolution process is used to treat water-soluble fast-acting inorganic nutrients, ammonium polyphosphate slow-release inorganic nutrients, and EDTA chelated trace elements; First stage room temperature dissolution: Urea ammonium nitrate and potassium sulfate fast-acting components are dissolved in deionized water at 20-25℃ and stirred for 10-15 minutes until the system is completely clear. Secondary isothermal activation and dissolution: Under constant temperature conditions of 40-50℃, disperse and dissolve the slow-release component of ammonium polyphosphate and the trace elements chelated with EDTA, stir for 15-20 min to complete the activation and dispersion of the slow-release nutrients, and control the particle size of the inorganic solution solid phase particles ≤5μm; the mass ratio of the fast-acting inorganic nutrients, slow-release inorganic nutrients and chelated trace elements is (35-45):(12-18):(3-8); S3, Gradient Composite High-Shear Sustained-Release Gel-Forming Reaction: The modified organic mother liquor prepared in S1 is pumped into a closed emulsification reactor and preheated to 35-45℃. The inorganic nutrient solution prepared in S2 is added dropwise at a low speed with stirring, and the dropwise addition time is controlled to be 40-60 min to achieve gradient fusion of the organic and inorganic phases. After the dropwise addition is completed, magnesium aluminum silicate-nonionic polyacrylamide composite suspension stabilizer and sulfonated lignin gel sustained-release agent are added. The high-shear emulsification mode of 2800-3200 r / min is switched, and emulsification is carried out for 20-30 min to construct an organic-inorganic cross-linked three-dimensional network sustained-release structure in situ, resulting in a uniform and stable composite suspension system. S4. Constant Temperature and Precise pH Maturation and Shaping: The emulsified compound liquid is transferred to a sealed, light-proof maturation tank and matured for 18-24 hours at a constant temperature of 25-30℃ and a stirring speed of 60-80r / min. During the maturation process, the pH of the system is monitored in real time, and a phosphoric acid-potassium hydroxide weak buffer system is used for micro-adjustment to stabilize the pH of the system at 5.5-7.0, solidifying the three-dimensional network slow-release structure and obtaining the initial slow-release compound liquid fertilizer. S5. Drip irrigation ratio adapted to different growth stages: Based on the nutrient requirements of crops at different growth stages, differentiated liquid-water dilution ratios are adopted: seedling stage dilution ratio 1:(800-1000), growth stage dilution ratio 1:(500-700), and fruit expansion stage dilution ratio 1:(300-400). After dilution, the solution is filtered through a two-stage process of 100-mesh coarse filtration and 200-mesh fine filtration to remove trace agglomerates, thus producing a drip irrigation-specific slow-release organic-inorganic compound liquid fertilizer.

2. The drip irrigation-specific formulation process for the slow-release organic-inorganic compound liquid fertilizer according to claim 1, characterized in that: In step S1, the humic acid stock solution has a mass concentration of 45%-55% and an effective humic acid content of ≥35%; the plant compound amino acid solution has a total free amino acid and polypeptide content of ≥120g / L; the seaweed polysaccharide solution has an active polysaccharide content of ≥30g / L; the modified organic mother liquor has no stratification or precipitation after standing at room temperature for 72h, and the flocculation rate of the system is ≤0.5%.

3. The drip irrigation-specific formulation process for the slow-release organic-inorganic compound liquid fertilizer according to claim 1, characterized in that: In step S2, the trace elements chelated by EDTA are a composite system of chelated calcium, chelated magnesium, chelated iron, chelated zinc, and chelated boron, and are all prepared using chelated raw materials.

4. The drip irrigation-specific formulation process for the slow-release organic-inorganic compound liquid fertilizer according to claim 1, characterized in that: In step S3, the mass ratio of magnesium aluminum silicate to nonionic polyacrylamide is (8-12):1, the amount of compound suspension stabilizer added is 0.8%-1.5% of the total mass of the composite system, and the amount of sulfonated lignin gel slow-release additive added is 1.0%-2.0% of the total mass of the composite system.

5. The drip irrigation-specific formulation process for the slow-release organic-inorganic compound liquid fertilizer according to claim 1, characterized in that: In step S4, pH adjustment is carried out by adding small amounts multiple times, with the amount of the regulator added at one time not exceeding 0.1% of the total mass of the system; after maturation and shaping, the viscosity of the compound liquid fertilizer is 15-25 mPa·s.

6. The drip irrigation-specific formulation process for the slow-release organic-inorganic compound liquid fertilizer according to claim 1, characterized in that: In step S5, the maximum particle size of the liquid fertilizer after two-stage filtration is ≤2μm.

7. The slow-release organic-inorganic compound liquid fertilizer according to any one of claims 1-6, characterized in that, By mass percentage, the raw material components include: 38%-48% modified organic mother liquor, 25%-35% readily available inorganic nutrients, 10%-15% ammonium polyphosphate slow-release inorganic nutrients, 3%-8% EDTA chelated trace elements, 1.0%-2.0% sulfonated lignin gel slow-release adjuvant, 0.8%-1.5% magnesium aluminum silicate compound suspension stabilizer, and the balance being deionized water.

8. The slow-release organic-inorganic compound liquid fertilizer according to claim 7, characterized in that: The liquid fertilizer exhibits no stratification, demulsification, or sedimentation after 90 days of sealed storage at room temperature; the initial nutrient release rate is ≤25% from 0-15 days, the stable nutrient release rate is 60%-70% from 15-60 days, and the residual slow-release nutrients are ≥15% after 60 days.

9. The slow-release organic-inorganic compound liquid fertilizer according to claim 7, characterized in that: The liquid fertilizer is suitable for soil environments with a pH of 5.0-8.5 and is used for drip irrigation fertilization of crops.

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