Modified nano double-chelated medium trace element water-soluble fertilizer

Abstract

The invention discloses a water-soluble fertilizer containing modified nano double-chelated medium trace elements, and belongs to the technical field of biological agriculture. The fertilizer is composed of sorbitol, glycerin, EDTA iron, EDTA zinc, potassium citrate, calcium citrate, magnesium sulfate heptahydrate, disodium ethylene diamine tetraacetate, an auxiliary agent and the like. The auxiliary agent is prepared from carboxymethyl chitosan, a modified nano auxiliary agent and polyethylene glycol, and the modified nano auxiliary agent is prepared from amylopectin, 8-hydroxyquinolone and isopropyl tri (dioctyl pyrophosphate acyloxy) titanate through a reaction. By adopting a double-chelation technology and a nanotechnology, the stability of trace elements in the fertilizer is remarkably improved, and nutrients are prevented from being lost and fixed in soil. And the absorption efficiency of the plants on elements such as iron, zinc and magnesium is improved by the nano-scale particles and the chelated nutrients. Field tests show that the fertilizer can significantly promote the growth of mung bean sprouts and improve the biomass and the content of medium trace elements in plants.

Description

Technical Field

[0001] The present invention belongs to the technical field of biological agriculture, and specifically relates to a water-soluble fertilizer containing modified nano double-chelated medium and trace elements. Background Art

[0002] With the rapid development of modern agriculture, the demand for high-yield and high-quality crops is increasing continuously, and the lack of trace elements in the soil is becoming increasingly prominent. Trace elements such as iron, zinc, manganese, copper, etc. are indispensable nutrients in the process of plant growth and metabolism, and play an important role in improving crop yield and quality. However, due to the long-term application of a large amount of single nitrogen, phosphorus, and potassium fertilizers, the trace elements in the soil are gradually depleted. At the same time, affected by factors such as soil pH change and redox reaction, trace elements are easily fixed or transformed into insoluble compounds, resulting in low plant absorption and utilization rate, thus causing crop nutrient deficiency symptoms and affecting agricultural production efficiency.

[0003] Traditional trace element fertilizers usually exist in the form of inorganic salts, but their stability is poor and they are easily inactivated by environmental conditions. In addition, they are easily lost or fixed by the soil after application, with low utilization rate and may cause pollution to the environment. To improve the utilization efficiency of trace element fertilizers, chelation technology and nanotechnology have gradually been introduced into the agricultural field. Chelation technology combines trace elements with organic molecules by using chelating agents (such as EDTA, citric acid, etc.) to form stable chelated compounds, thereby improving their stability in the soil and plant absorption efficiency; while nanotechnology utilizes the high specific surface area and special surface effects of materials to make fertilizers have better solubility and adsorption, thus further enhancing the plant's ability to absorb nutrients.

[0004] In recent years, double-chelating technology, as a new method for preparing micronutrient fertilizers, by jointly using two different types of chelating agents (such as sugar alcohols and organic acids), can not only significantly improve the stability of trace elements, but also achieve the combination of slow release and quick effect of nutrients, meeting the needs of crops for medium and trace elements at different growth stages. However, at present, the water-soluble fertilizer products on the market still have the problem of insufficient pertinence in formula design and are difficult to meet the needs of different soil conditions and crop varieties. Therefore, developing a new type of water-soluble fertilizer containing medium and trace elements based on modified nano double-chelating technology can not only improve fertilizer utilization rate, but also effectively improve the soil environment, providing an efficient and environmentally friendly solution for agricultural production. Summary of the Invention

[0005] Problems to be Solved

[0006] Traditional trace element fertilizers lack stability. Trace elements in the form of inorganic salts are susceptible to soil pH fluctuations (4.5 - 8.0), redox potential (Eh > 200 mV), and colloid adsorption, resulting in the fixation rates of available Fe³⁺ and Zn²⁺ reaching 60% - 85% and 45% - 75% respectively; the chelating ability of the single chelation system (such as EDTA) decreases in alkaline soil, and the dissociation rate of Fe - EDTA increases to 38% - 52% when pH > 7.5; limitations in the efficacy of existing technologies: conventional nano-fertilizers have uneven particle size distribution (200 - 500 nm) and insufficient specific surface area (the dispersion stability decreases by 40% - 65%). Defects in agricultural production adaptability, traditional micronutrient fertilizers lack dynamic chelation regulation and cannot meet the requirements of both quick-acting (release degree > 80% in 24 hours) and long-acting (sustained release for 60 days) at the same time; existing formulations are difficult to adapt to different soil types (such as red soil with CEC 30 cmol / kg), resulting in significant regional applicability differences.

[0007] Technical solution

[0008] To solve the above problems, the present invention adopts the following technical solutions.

[0009] A water-soluble fertilizer containing modified nano double chelated medium and trace elements, which is composed of the following components by weight percentage: sorbitol (CAS No.: 50-70-4) 5%-15%, glycerol (CAS No.: 77944-79-7) 3%-10%, EDTA iron (CAS No.: 15708-41-5) 2%-6%, EDTA zinc (CAS No.: 14025-21-9) 1%-5%, potassium citrate (CAS No.: 866-84-2) 3%-8%, calcium citrate (CAS No.: 813-94-5) 2%-6%, magnesium sulfate heptahydrate (CAS No.: 10034-99-8) 2%-8%, disodium ethylenediaminetetraacetate (CAS No.: 139-33-3) 1%-5%, auxiliary agent 5%-10%, and the balance is deionized water; the preparation method of the auxiliary agent is as follows: dissolve carboxymethyl chitosan (CAS No.: 83512-85-0) in an acetic acid (CAS No.: 64-19-7) solution with a mass percentage of 1%-4% and 3-7 times its mass, stir at 30°C for 8h-10h, then add a modified nano auxiliary agent with a mass 0.2-0.8 times that of carboxymethyl chitosan, and then add polyethylene glycol (CAS No.: 25322-68-3) with a mass 2-5 times that of carboxymethyl chitosan, and stir at 60°C-80°C for 6h-10h to obtain it; the preparation method of the modified nano auxiliary agent is as follows: disperse amylopectin (CAS No.: 9037-22-3) in deionized water with a mass 10-20 times its mass, then add 8-hydroxyquinoline (CAS No.: 148-24-3) with a mass 2-8 times that of amylopectin, and stir at 50°C-60°C for 2h, then add isopropyltri(dioctylpyrophosphato)titanate (CAS No.: 65345-34-8) with a mass 1-5 times that of amylopectin, react at 120°C-140°C for 4h-8h, cool and collect the precipitate to obtain it.

[0010] The water-soluble fertilizer containing modified nano double chelated medium and trace elements is composed of the following components by weight percentage: sorbitol 8%-13%, glycerol 5%-9%, EDTA iron 3%-6%, EDTA zinc 1%-4%, potassium citrate 4%-8%, calcium citrate 2%-5%, magnesium sulfate heptahydrate 4%-8%, disodium ethylenediaminetetraacetate 1%-4%, auxiliary agent 7%-10%, and the balance is deionized water; the preparation method of the auxiliary agent is as follows: dissolve carboxymethyl chitosan in an acetic acid solution with a mass percentage of 1%-3% and 4-7 times its mass, stir at 30°C for 8h-10h, then add a modified nano auxiliary agent with a mass 0.3-0.6 times that of carboxymethyl chitosan, and then add polyethylene glycol with a mass 2-5 times that of carboxymethyl chitosan, and stir at 65°C-80°C for 7h-10h to obtain it.

[0011] The water-soluble fertilizer of modified nano double-chelated medium and trace elements is composed of the following components by weight percentage: sorbitol 11%, glycerol 8%, EDTA iron 5%, EDTA zinc 3%, potassium citrate 6%, calcium citrate 4%, magnesium sulfate heptahydrate 6%, disodium ethylenediaminetetraacetate 3%, auxiliary agent 9%, and the balance is deionized water; the preparation method of the auxiliary agent is as follows: dissolve carboxymethyl chitosan in an acetic acid solution with a mass percentage of 2% that is 6 times its mass, stir at 30 °C for 9 h, then add a modified nano auxiliary agent that is 0.5 times the mass of carboxymethyl chitosan, and then add polyethylene glycol that is 4 times the mass of carboxymethyl chitosan, and stir at 75 °C for 9 h to obtain it.

[0012] In the water-soluble fertilizer of modified nano double-chelated medium and trace elements, the EDTA iron is ferric disodium ethylenediaminetetraacetate, and the chelated iron content is 13%-15% of the total mass, and the total chelation fraction ≥ 99%.

[0013] In the water-soluble fertilizer of modified nano double-chelated medium and trace elements, the EDTA zinc is zinc sodium ethylenediaminetetraacetate, and its preparation method is as follows: dissolve EDTA tetrasodium and zinc sulfate in deionized water according to a molar ratio of 1.2:1, react at 80 °C - 95 °C for 2 - 5 h, control the pH value to 5.5 - 7.0, spray-dry into nano-scale particles, the inlet temperature of spray-drying is 160 °C, the outlet temperature of spray-drying is 90 °C, the particle size is 100 nm, the chelated zinc content ≥ 14.5%, the water-insoluble matter ≤ 0.1%, and the pH value is 6.0 - 7.0.

[0014] In the water-soluble fertilizer of modified nano double-chelated medium and trace elements, the parameters of amylopectin are as follows: the molecular weight range is from 4 million to 6 million, and it is composed of 20,000 - 300,000 glucose units.

[0015] In the water-soluble fertilizer of modified nano double-chelated medium and trace elements, after adding the modified nano auxiliary agent, heat treatment is carried out. First, heat up to 45 °C at a rate of 0.5 °C / min and stir for 2 h - 4 h.

[0016] In the water-soluble fertilizer of modified nano double-chelated medium and trace elements, the parameters of polyethylene glycol are as follows: the number-average molecular weight is 2000 Da.

[0017] In the water-soluble fertilizer of modified nano double-chelated medium and trace elements, the water-soluble fertilizer is prepared by the following process: add deionized water and disodium ethylenediaminetetraacetate into a reaction kettle, heat to 40 - 60 °C, add sorbitol, glycerol, potassium citrate, and calcium citrate in sequence, stir evenly, add EDTA iron, EDTA zinc, magnesium sulfate heptahydrate, and the auxiliary agent in sequence, continue to stir until completely dissolved, cool to room temperature and then filter, and select a filtration particle size of 2 μm to obtain the finished product.

[0018] Beneficial effects

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] Improve fertilizer stability. By adopting the double chelation technology (combining EDTA and citrate) and modified nano additives, the present invention significantly enhances the stability of medium and trace elements in fertilizers. This design effectively prevents the loss and fixation of nutrients in the soil, enabling the fertilizer to maintain high efficiency under complex environmental conditions. Enhance nutrient absorption efficiency. The introduction of nano-scale particles and chelated nutrients in the fertilizer greatly improves the absorption efficiency of plants for medium and trace elements (such as iron, zinc, and magnesium). The application of nanotechnology increases the solubility and surface activity of the fertilizer, while chelation technology ensures that nutrients exist in a form easily absorbed by plants, thereby reducing nutrient waste. Promote plant growth. Field tests show that after using the water-soluble fertilizer of the present invention, the growth rate and biomass of mung bean sprouts are significantly improved. Compared with the control group, both the length and total fresh weight of the bean sprouts are significantly increased, proving that the fertilizer has excellent effects in promoting plant growth. Improve the nutrient content of plants. After applying this fertilizer, the content of medium and trace elements (such as Fe, Zn, Mg) in plants increases significantly. This result indicates that the fertilizer not only provides sufficient nutrient supply but also effectively improves the absorption and utilization ability of plants for these elements. Environmentally friendly. By optimizing the nutrient utilization efficiency, the present invention reduces the potential pollution caused by the application amount of fertilizers and nutrient loss to the environment. This characteristic makes it meet the requirements of sustainable development of modern agriculture and has high environmental protection value. Formulation flexibility. The formulation design of this fertilizer has high flexibility and can be adjusted according to the specific requirements of different crop varieties and soil conditions, thus meeting diverse agricultural production scenarios and enhancing its practicality and promotion value. In summary, the water-soluble fertilizer of the present invention combines modified nanotechnology and double chelation technology, and performs excellently in improving fertilizer stability, nutrient absorption efficiency, and promoting plant growth. At the same time, its environmental friendliness and formulation flexibility further highlight its technical advantages and broad application prospects. This innovation provides an efficient and environmentally friendly solution for modern agriculture and has significant practical value. Description of the Drawings

[0021] Figure 1 It is a diagram of the cultivation state of mung bean sprouts in the present invention. Detailed Embodiments

[0022] The present invention will be further described below in conjunction with specific embodiments.

[0023] Unless otherwise defined, the technical and scientific terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art to which the present invention belongs. In actual application, the weight unit involved in the present invention can be set to the unit kilogram.

[0024] Example 1

[0025] Water-soluble fertilizer with modified nano double chelated medium and trace elements, which is composed of the following components by weight percentage: sorbitol 5%, glycerol 10%, EDTA iron 2%, EDTA zinc 5%, potassium citrate 3%, calcium citrate 6%, magnesium sulfate heptahydrate 2%, disodium ethylenediaminetetraacetate 5%, auxiliary agent 5%, and the balance is deionized water; the preparation method of the auxiliary agent is as follows: dissolve carboxymethyl chitosan in acetic acid solution with a mass percentage of 4% which is 3 times its mass, stir at 30 °C for 8 h, then add a modified nano auxiliary agent which is 0.8 times the mass of carboxymethyl chitosan, and then add polyethylene glycol which is 2 times the mass of carboxymethyl chitosan, and stir at 80 °C for 6 h to obtain; the preparation method of the modified nano auxiliary agent is as follows: disperse amylopectin in deionized water which is 20 times its mass, then add 8-hydroxyquinoline which is 2 times the mass of amylopectin, and stir at 60 °C for 2 h, then add isopropyltri(dioctylpyrophosphato) titanate which is 1 times the mass of amylopectin, react at 140 °C for 4 h, cool and collect the precipitate to obtain.

[0026] Among them: EDTA iron is sodium iron ethylenediaminetetraacetate, in which the chelated iron content is 13% of the total mass, and the total chelation fraction is 99.4%. Among them: EDTA zinc is zinc sodium ethylenediaminetetraacetate, and its preparation method is as follows: dissolve EDTA tetrasodium and zinc sulfate in deionized water according to a molar ratio of 1.2:1, react at 95 °C for 2 h, control the pH value to 7.0, and spray dry into nano-scale particles, in which the chelated zinc content is 14.8%, the water-insoluble matter ≤ 0.1%, and the pH value is 6.0. Among them: the parameters of amylopectin are as follows: the molecular weight range is 4 million to 6 million, and it is composed of 20,000 - 300,000 glucose units. Among them: after adding the modified nano auxiliary agent, heat treatment is carried out, first heat up to 45 °C at a rate of 0.5 °C / min and stir for 4 h. Among them: the parameters of polyethylene glycol are as follows: the number-average molecular weight is 2000 Da. Among them: the water-soluble fertilizer is prepared by the following process: add deionized water and disodium ethylenediaminetetraacetate into the reaction kettle, heat to 60 °C, add sorbitol, glycerol, potassium citrate, and calcium citrate in sequence, stir evenly, add EDTA iron, EDTA zinc, magnesium sulfate heptahydrate and the auxiliary agent in turn, continue to stir until completely dissolved, cool to room temperature and then filter to obtain the finished product.

[0027] Example 2

[0028] Water-soluble fertilizer containing modified nano double-chelated medium and trace elements, which is composed of the following components by weight percentage: sorbitol 15%, glycerol 3%, EDTA iron 6%, EDTA zinc 1%, potassium citrate 8%, calcium citrate 2%, magnesium sulfate heptahydrate 8%, disodium ethylenediaminetetraacetate 1%, auxiliary agent 10%, and the balance is deionized water; the preparation method of the auxiliary agent is as follows: dissolve carboxymethyl chitosan in an acetic acid solution with a mass percentage of 1% that is 7 times its mass, stir at 30°C for 10 h, then add a modified nano auxiliary agent that is 0.2 times the mass of carboxymethyl chitosan, and then add polyethylene glycol that is 5 times the mass of carboxymethyl chitosan, and stir at 60°C for 10 h to obtain it; the preparation method of the modified nano auxiliary agent is as follows: disperse amylopectin in deionized water that is 10 times its mass, then add 8-hydroxyquinoline that is 8 times the mass of amylopectin, and stir at 50°C for 2 h, then add isopropyltri(dioctylpyrophosphato)titanate that is 5 times the mass of amylopectin, react at 120°C for 8 h, cool, and collect the precipitate to obtain it.

[0029] Among them: EDTA iron is sodium ferric ethylenediaminetetraacetate, in which the chelated iron content is 15% of the total mass, and the total chelation fraction is 99.7%. Among them: EDTA zinc is zinc sodium ethylenediaminetetraacetate, and its preparation method is as follows: dissolve EDTA tetrasodium and zinc sulfate in deionized water according to a molar ratio of 1.2:1, react at 80°C for 5 h, control the pH value to 5.5, and spray dry into nano-scale particles, in which the chelated zinc content is 15.2%, the water-insoluble matter ≤ 0.1%, and the pH value is 7.0. Among them: the parameters of amylopectin are as follows: the molecular weight range is from 4 million to 6 million, and it is composed of 20,000 - 300,000 glucose units. Among them: after adding the modified nano auxiliary agent, heat treatment is carried out, first heat up to 45°C at a rate of 0.5°C / min and stir for 2 h. Among them: the parameters of polyethylene glycol are as follows: the number-average molecular weight is 2000 Da. Among them: the above water-soluble fertilizer is prepared by the following process: add deionized water and disodium ethylenediaminetetraacetate into a reaction kettle, heat to 40°C, add sorbitol, glycerol, potassium citrate, and calcium citrate in sequence, stir evenly, add EDTA iron, EDTA zinc, magnesium sulfate heptahydrate, and the auxiliary agent in sequence, continue to stir until completely dissolved, cool to room temperature, and filter to obtain the finished product.

[0030] Example 3

[0031] Water-soluble fertilizer containing modified nano double chelated medium and trace elements, which is composed of the following components by weight percentage: sorbitol 10%, glycerol 6%, EDTA iron 4%, EDTA zinc 3%, potassium citrate 5%, calcium citrate 4%, magnesium sulfate heptahydrate 5%, disodium ethylenediaminetetraacetate 3%, auxiliary agent 8%, and the balance is deionized water; the preparation method of the auxiliary agent is as follows: dissolve carboxymethyl chitosan in acetic acid solution with a mass percentage of 3% which is 5 times its mass, stir at 30 °C for 9 h, then add modified nano auxiliary agent which is 0.5 times the mass of carboxymethyl chitosan, and then add polyethylene glycol which is 4 times the mass of carboxymethyl chitosan, and stir at 70 °C for 10 h to obtain; the preparation method of the modified nano auxiliary agent is as follows: disperse amylopectin in deionized water which is 10 times its mass, then add 8-hydroxyquinoline which is 8 times the mass of amylopectin, and stir at 50 °C for 2 h, then add isopropyltri(dioctylpyrophosphato) titanate which is 5 times the mass of amylopectin, react at 120 °C for 8 h, cool and collect the precipitate to obtain.

[0032] Among them: EDTA iron is sodium ferric ethylenediaminetetraacetate, in which the chelated iron content is 15% of the total mass, and the total chelation fraction is 99.8%. Among them: EDTA zinc is zinc sodium ethylenediaminetetraacetate, and its preparation method is as follows: dissolve EDTA tetrasodium and zinc sulfate in deionized water according to a molar ratio of 1.2:1, react at 88 °C for 4 h, control the pH value to 7.0, and spray dry into nano-scale particles, in which the chelated zinc content is 15.5%, the water-insoluble matter ≤ 0.1%, and the pH value is 6.5. Among them: the parameters of amylopectin are as follows: the molecular weight range is from 4 million to 6 million, and it is composed of 20,000 - 300,000 glucose units. Among them: after adding the modified nano auxiliary agent, heat treatment is carried out, first heat up to 45 °C at a rate of 0.5 °C / min and stir for 3 h. Among them: the parameters of polyethylene glycol are as follows: the number-average molecular weight is 2000 Da. Among them: the water-soluble fertilizer is prepared by the following process: add deionized water and disodium ethylenediaminetetraacetate into the reaction kettle, heat to 50 °C, add sorbitol, glycerol, potassium citrate, and calcium citrate in sequence, stir evenly, add EDTA iron, EDTA zinc, magnesium sulfate heptahydrate and the auxiliary agent in turn, continue to stir until completely dissolved, cool to room temperature and then filter to obtain the finished product.

[0033] Comparative Examples 1 - 5

[0034] Comparative Example 1: The same as Example 3, but without adding the auxiliary agent.

[0035] Comparative Example 2: The same as Example 3, but without adding the modified nano auxiliary agent.

[0036] Comparative Example 3: The same as Example 3, but without adding polyethylene glycol in the auxiliary agent.

[0037] Comparative Example 4: The same as Example 3, using 5-chloro-8-hydroxyquinoline (CAS No.: 130-16-5) to replace 8-hydroxyquinolone in the modified nano-additive.

[0038] Comparative Example 5: The same as Example 3, using aluminate coupling agent (DL-411 type, CAS No.: 68953-84-4) to replace isopropyltris(dioctylpyrophosphato)titanate in the modified nano-additive.

[0039] Field test: Taking mung bean sprouts as an example, evaluate the effects of the patented fertilizer on the growth rate, biomass and nutrient content of the sprouts. Compare with the comparative example fertilizer and the example fertilizer. Use mung beans (Vigna radiata), and select seeds with plump grains and no pests and diseases. Use a plastic germination tray (30 cm × 20 cm × 5 cm) for the germination treatment of mung bean sprouts. The addition concentration of the fertilizer is 1 g / L. Place 100 g of mung beans in each plastic germination tray. Place the plastic germination tray in a constant temperature incubator at a temperature of 25°C ± 2°C and a relative humidity of 70%. The light conditions are as follows: avoid light in the initial stage of sprout growth (the first 3 days), and provide scattered light (1000 lux) in the later stage (the 4th day). The growth cycle is 5 days, as Figure 1 shown. Measurement indicators: Measure the length from the root tip to the bud tip; Fresh weight: Harvest all the sprouts in each germination tray and weigh the total fresh weight (g / tray); Then wash the sprouts with deionized water, dry and crush them. Treat the samples with nitric acid digestion method, and use an inductively coupled plasma emission spectrometer to measure the contents of Fe, Zn, and Mg elements (mg / kg dry weight). The results are shown in Table 1.

[0040] Table 1 Test Results

[0041]

[0042] The field test results of the embodiments of the present invention and the comparative examples reveal the significant promoting effect of the modified nano double-chelated water-soluble fertilizer on the growth of mung bean sprouts. In terms of growth indicators, Example 3 performed the best: the sprout length reached 16.2 ± 0.5 cm, the total fresh weight was 352 ± 15 g / dish, and the contents of Fe (165 ± 7 mg / kg), Zn (112 ± 5 mg / kg), and Mg (682 ± 30 mg / kg) were significantly higher than those of other groups. Compared with Comparative Example 1 without additives, the sprout length of Example 3 increased by 54% and the fresh weight increased by 31%, which is attributed to the synergistic effect of its unique double-chelated system and nanotechnology. The key mechanism of action is as follows: (1) Double-chelated stable system: The dual chelation of EDTA and citrate forms a three-dimensional protective structure: EDTA forms a five-membered ring chelate with metal ions through four carboxyl groups (chelation fraction ≥ 99%) and remains stable within a wide pH range; the hydroxyl and carboxyl groups of citrate provide secondary ligand sites to form a dynamic chelation network and slowly release nutrients. (2) Nano-enhancing mechanism: The nano-scale particles (particle size 100 nm) prepared by spray drying have: a specific surface area increased by 10³ times, enhancing the contact probability with plant roots; an increase in surface hydroxyl active sites, promoting transmembrane transport; a three-dimensional network structure formed by nano-additives derived from amylopectin, delaying nutrient loss. (3) Synergistic effect of functional additives: Carboxymethyl chitosan-polyethylene glycol complex: forms a molecular cage through hydrogen bonding and hydrophobic interactions to encapsulate trace elements (drug loading up to 23.7%); titanate-modified additive: the pyrophosphoryl oxygen group undergoes coordination exchange with soil colloids to reduce nutrient fixation; 8-hydroxyquinoline: as an electron transfer medium, improving the reduction efficiency of Fe³⁺ by plant cells (improvement rate 38%). The experimental data verify that the fertilizer maximizes the nutrient utilization efficiency through a dual physical and chemical action mechanism. In particular, the synergistic ratio of nano-scale EDTA zinc (particle size 100 nm) and calcium citrate increases the Mg absorption efficiency by 2.3 times compared with conventional fertilizers. This design provides a precise nutrition solution with both rapid and long-term effects for modern agriculture.

[0043] The above content further elaborates on the present invention in combination with specific embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the field of bio-agricultural technology to which the present invention pertains, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, which should all be regarded as falling within the protection scope determined by the claims submitted for the present invention.

Claims

1. A modified nano double chelated water-soluble fertilizer of trace elements, characterized in that: The invention is composed of the following components by weight percentage: 5%-15% sorbitol, 3%-10% glycerol, 2%-6% EDTA iron, 1%-5% EDTA zinc, 3%-8% potassium citrate, 2%-6% calcium citrate, 2%-8% magnesium sulfate heptahydrate, 1%-5% disodium ethylenediaminetetraacetic acid, 5%-10% auxiliary agent, and the balance is deionized water; wherein the preparation method of the auxiliary agent is as follows: dissolve carboxymethyl chitosan in a 1%-4% acetic acid solution of 3-7 times its mass, stir at 30°C for 8h-10h, and then add 0.2-0.8% carboxymethyl chitosan. times the mass of the modified nano-additive, then adding polyethylene glycol in an amount of 2-5 times the mass of the carboxymethyl chitosan, and stirring at 60°C-80°C for 6h-10h to obtain the modified nano-additive; wherein the preparation method of the modified nano-additive is as follows: the amylopectin is dispersed in deionized water in an amount of 10-20 times the mass of the amylopectin, then 8-hydroxyquinolone in an amount of 2-8 times the mass of the amylopectin is added, and stirring at 50°C-60°C for 2h, and then isopropyl tri(dioctyl pyrophosphate) titanate in an amount of 1-5 times the mass of the amylopectin is added, reacting at 120°C-140°C for 4h-8h, and collecting the precipitate after cooling to obtain the modified nano-additive.

2. The modified nano double-chelated water-soluble fertilizer of trace elements according to claim 1, characterized in that: The invention is composed of the following components by weight percentage: 8%-13% sorbitol, 5%-9% glycerol, 3%-6% EDTA iron, 1%-4% EDTA zinc, 4%-8% potassium citrate, 2%-5% calcium citrate, 4%-8% magnesium sulfate heptahydrate, 1%-4% disodium ethylenediaminetetraacetic acid, 7%-10% auxiliary agent, and the balance is deionized water; wherein the preparation method of the auxiliary agent is as follows: dissolving carboxymethyl chitosan in a 1%-3% acetic acid solution of 4-7 times the mass of the carboxymethyl chitosan, stirring at 30°C for 8h-10h, then adding a modified nano auxiliary agent of 0.3-0.6 times the mass of the carboxymethyl chitosan, and subsequently adding polyethylene glycol of 2-5 times the mass of the carboxymethyl chitosan, and stirring at 65°C-80°C for 7h-10h to obtain the auxiliary agent.

3. The modified nano double-chelated water-soluble fertilizer of trace elements according to claim 2, characterized in that: The invention is composed of the following components by weight percentage: 11% sorbitol, 8% glycerol, 5% EDTA iron, 3% EDTA zinc, 6% potassium citrate, 4% calcium citrate, 6% magnesium sulfate heptahydrate, 3% disodium ethylenediaminetetraacetic acid, 9% auxiliary agent, and the balance is deionized water; wherein the preparation method of the auxiliary agent is as follows: dissolve carboxymethyl chitosan in a 2% acetic acid solution with a mass percentage of 6 times the mass of the carboxymethyl chitosan, stir at 30°C for 9h, then add a modified nano auxiliary agent with a mass percentage of 0.5 times the mass of the carboxymethyl chitosan, and then add polyethylene glycol with a mass percentage of 4 times the mass of the carboxymethyl chitosan, and stir at 75°C for 9h to obtain the auxiliary agent.

4. The modified nano double-chelated water-soluble fertilizer of trace elements according to claim 1, characterized in that: EDTA iron is disodium ferric ethylenediaminetetraacetate, in which the chelated iron content is 13%-15% of the total mass, and the total chelated fraction is ≥99%.

5. The modified nano double-chelated water-soluble fertilizer of trace elements according to claim 1, characterized in that: EDTA zinc is ethylenediaminetetraacetic acid zinc sodium salt, and its preparation method is as follows: tetrasodium EDTA and zinc sulfate are dissolved in deionized water at a molar ratio of 1.2:1, reacted at 80℃-95℃ for 2-5h, the pH value is controlled at 5.5-7.0, and spray-dried into nano-scale particles, wherein the chelated zinc content is ≥14.5%, the water-insoluble matter is ≤0.1%, and the pH value is 6.0-7.

0.

6. The modified nano double-chelated water-soluble fertilizer of trace elements according to claim 1, characterized in that: The parameters of amylopectin are as follows: molecular weight ranges from 4 million to 6 million, and is composed of 20,000-300,000 glucose units.

7. The modified nano double-chelated water-soluble fertilizer of trace elements according to claim 1, characterized in that: After adding the modified nano-additive, the temperature was raised to 45°C at a rate of 0.5°C / min and then stirred for 2h-4h.

8. The modified nano double-chelated water-soluble fertilizer of trace elements according to claim 1, characterized in that: The parameters of polyethylene glycol are as follows: the number average molecular weight is 2000 Da.

9. The modified nano double-chelated water-soluble fertilizer of trace elements according to claim 1, characterized in that: The water-soluble fertilizer is prepared by the following process: deionized water and disodium ethylenediaminetetraacetate are added into a reaction kettle, heated to 40-60°C, sorbitol, glycerol, potassium citrate and calcium citrate are added in sequence, stirred evenly, EDTA iron, EDTA zinc, magnesium sulfate heptahydrate and additives are added in sequence, stirring is continued until completely dissolved, and the mixture is filtered after being cooled to room temperature to obtain a finished product.

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