Special medium trace element fertilizer for flue-cured tobacco and preparation method of special medium trace element fertilizer

Abstract

The invention relates to the field of fertilizers, in particular to a special medium trace element fertilizer for flue-cured tobaccos and a preparation method thereof.By compounding a medium element compound and a trace element compound, nutrients needed in the growth and development process of the flue-cured tobaccos are effectively supplemented, the disease resistance of the flue-cured tobaccos is improved, and the disease loss of the flue-cured tobaccos is reduced; in addition, the sulfur-doped derivative carbon spheres A and the sulfur-doped derivative carbon spheres B are mixed according to a specific proportion, cavities in the sulfur-doped derivative carbon spheres A and the sulfur-doped derivative carbon spheres B can be used for loading part of small-molecule compounds, the release path of the small-molecule compounds is prolonged, and compared with a traditional coated slow-release controlled-release fertilizer in the prior art, the slow-release controlled-release fertilizer has the advantages that the slow-release controlled-release effect is greatly improved. According to the method, introduction of a coating material is avoided, so that the adverse effect of the coating material on soil and flue-cured tobacco crops can be effectively reduced, and the effect can still be played for a long time even if the fertilizer is not coated, so that the method has a wide application prospect.

Description

Technical Field

[0001] The invention relates to the field of fertilizers, and in particular to a medium and trace element fertilizer special for flue-cured tobacco and a preparation method thereof. Background Art

[0002] Flue-cured tobacco requires macroelements, medium elements and trace elements for growth and development. Different nutrients have different physiological functions and play an important role in tobacco plant growth and development and material metabolism. Affected by soil nutrients, tobacco field fertilization, tobacco plant growth and ecological environment, different symptoms of nutrient deficiency often occur in flue-cured tobacco production, such as potassium deficiency, boron deficiency, zinc deficiency, etc. When tobacco plants lack nutrients, topdressing through the soil takes a long time for fertilizer conversion and tobacco plant absorption, and the utilization rate is also low. Therefore, in flue-cured tobacco production, the method of spraying on the leaves is often used to supplement a certain amount of nutrients, balance nutrition, increase dry matter accumulation, and promote leaf yellowing.

[0003] Foliar fertilizers sprayed on the leaves of flue-cured tobacco are widely used in production, such as organic foliar fertilizers, inorganic foliar fertilizers, etc. These foliar fertilizers are not only suitable for flue-cured tobacco, but also can be used on other crops. Therefore, the nutrient ratio cannot be well formulated according to the growth and development, nutritional requirements and element deficiencies of flue-cured tobacco, and the specificity for the nutritional requirements of flue-cured tobacco is poor: At the same time, the foliar fertilizers sprayed and applied more in flue-cured tobacco production are either organic or inorganic single fertilizers, such as potassium dihydrogen phosphate and zinc sulfate, etc. There is a lack of special foliar fertilizers that combine organic and inorganic elements, have a multi-nutrient ratio and are suitable for spraying on the leaves of special economic crops such as flue-cured tobacco.

[0004] Therefore, according to the above-mentioned related technologies, it is urgent to develop a medium and trace element fertilizer specially used for flue-cured tobacco and a preparation method thereof. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a medium and trace element fertilizer for flue-cured tobacco and a preparation method thereof, so as to solve the problem that the medium and trace element fertilizer for flue-cured tobacco in the prior art has a relatively single function.

[0006] Based on the above purpose, the present invention provides a medium and trace element fertilizer specially used for flue-cured tobacco and a preparation method thereof.

[0007] A medium and trace element fertilizer specially used for flue-cured tobacco, comprising the following raw materials in parts by weight: 12-18 parts of a medium element complex, 8-11 parts of a trace element complex, 1-1.5 parts of sophorolipids, 0.04-0.08 parts of 2-amino-3-methylhexanoic acid, 2-4 parts of anhydrous citric acid, and 85.5-93 parts of deionized water; The intermediate element complex is prepared from a magnesium-containing compound, a calcium-containing compound and a sodium-containing compound; The trace element complex is prepared from a copper-containing compound, a zinc-containing compound, a boron-containing compound, a manganese-containing compound, a potassium-containing compound, a sodium-containing compound, a phosphorus-containing compound and sulfur-doped derived carbon balls; The sulfur-doped derived carbon balls are obtained by mixing sulfur-doped derived carbon balls A and sulfur-doped derived carbon balls B in a mass ratio of 2-6:1-1.5; The sulfur-doped derived carbon balls A are obtained by reacting magnesium sulfate, magnesium citrate and a carbon quantum dot solution; The sulfur-doped derived carbon balls B are obtained by reacting magnesium sulfate, magnesium citrate and a carbon quantum dot solution.

[0008] Preferably, the preparation process of the sulfur-doped derived carbon ball A is as follows: Step A1. Mix magnesium citrate, magnesium sulfate and carbon quantum dot solution evenly, stir at 75-85°C for 10-12h, and then dry in an oven at 75-85°C to obtain a solid powder; Step A2. Grind the solid powder in a mortar for 5-7 minutes, then carbonize it in a tubular furnace, start heating and heat preservation treatment, then cool to room temperature and soak it in 2-4 mol / L hydrochloric acid solution to remove impurities, then filter the mixed solution, and when the filtrate is neutral, place the obtained solid in an oven at 95-105°C to dry to obtain sulfur-doped derivative carbon balls A.

[0009] Preferably, the dosage ratio of magnesium citrate, magnesium sulfate and carbon quantum dot solution in step A1 is 0.4-0.8 g: 0.4-0.8 g: 145-155 mL; The process of the heating and heat preservation treatment in step A2 is as follows: heating from room temperature to 580-600° C. at a heating rate of 1.5-2° C. / min and keeping the temperature for 50-60 min.

[0010] Preferably, the preparation process of the sulfur-doped derived carbon balls B is as follows: Step B1. Mix the magnesium citrate, magnesium sulfate and carbon quantum dot solution evenly, stir at 75-85°C for 10-12h, and then dry in an oven at 75-85°C to obtain a solid powder; Step B2. Grind the solid powder in a mortar for 5-7 minutes, then carbonize it in a tubular furnace, start heating and heat preservation treatment, then cool to room temperature and soak it in 2-4 mol / L hydrochloric acid solution to remove impurities, then filter the mixed solution, and when the filtrate is neutral, place the obtained solid in an oven at 95-105°C to dry to obtain sulfur-doped derivative carbon balls B.

[0011] Preferably, the dosage ratio of magnesium citrate, magnesium sulfate and carbon quantum dot solution in step B1 is 0.4-0.8 g: 0.4-0.8 g: 145-155 mL.

[0012] Preferably, the process of heating and heat preservation treatment in step B2 is as follows: heating from room temperature to 580-600°C at a heating rate of 1.5-2°C / min and keeping warm for 50-60min, then heating to 680-700°C and keeping warm for 50-60min, and finally heating to 780-800°C and keeping warm for 50-60min.

[0013] Preferably, the concentration of the carbon quantum dot solution is 3-5 mg / mL; The preparation process of the carbon quantum dot solution is as follows: Step C1. Mix formic acid and hydrogen peroxide evenly, and ultrasonically vibrate for 12-15 minutes to obtain a mixed solution A; Step C2. pre-treating the lignite, coarsely grinding and sieving, taking the coal powder with a particle size of less than 0.074 mm and ball-milling it for 5-6 hours to obtain coal powder; Step C3. Add coal powder to mixed solution A, reflux at 75-80° C. for 160-180 min, filter the reaction mixture with a microporous filter membrane to remove insoluble fragments, and dialyze the filtered solution with a dialysis bag to neutrality to obtain a carbon quantum dot solution.

[0014] Preferably, the volume ratio of formic acid to hydrogen peroxide in step C1 is 90-110:15-25; The volume concentration of hydrogen peroxide in step C1 is 25%-35%; The mass ratio of the coal powder to the mixed liquid A in step C3 is 1.8-2.2 g: 105-135 mL; The particle size of the microporous filter membrane in step C3 is 0.4-0.5 μm; The molecular weight cut-off of the dialysis bag in step C3 is 80-100 Da.

[0015] Preferably, the copper-containing compound in the trace element complex is copper sulfate; The zinc compound in the trace element complex is zinc sulfate; The boron-containing compound in the trace element complex is boric acid; The manganese compound in the trace element complex is manganese sulfate monohydrate; The potassium compound in the trace element complex is potassium dihydrogen phosphate; The sodium compound in the trace element complex is sodium molybdate; The phosphorus-containing compound in the trace element complex is phosphoric acid; The magnesium compound in the middle element complex is obtained by mixing magnesium sulfate and magnesium sulfate heptahydrate in a mass ratio of 1.2-1.6:0.8-1.2; The calcium compound in the middle element complex is obtained by mixing EDTA chelated calcium and limestone in a mass ratio of 1-1.5:2-2.5; The sodium compound in the middle element complex is sodium silicate.

[0016] A method for preparing a medium and trace element fertilizer specially used for flue-cured tobacco comprises the following steps: Step S1. mixing a magnesium-containing compound, a calcium-containing compound and a sodium-containing compound to obtain a middle element complex; Step S2. mixing the sulfur-doped derived carbon balls A and the sulfur-doped derived carbon balls B to obtain sulfur-doped derived carbon balls; Step S3. mixing a copper-containing compound, a zinc-containing compound, a boron-containing compound, a manganese-containing compound, a potassium-containing compound, a sodium-containing compound, a phosphorus-containing compound and a sulfur-doped derived carbon ball to obtain a trace element complex; Step S4. dissolving the medium element complex, the trace element complex, sophorolipids, 2-amino-3-methylhexanoic acid, and anhydrous citric acid in deionized water, stirring evenly, to obtain a medium and trace element fertilizer for flue-cured tobacco; The mass ratio of the magnesium-containing compound, the calcium-containing compound and the sodium-containing compound in step S1 is 20-25:20-25:8-10; The mass ratio of the copper-containing compound, zinc-containing compound, boron-containing compound, manganese-containing compound, potassium-containing compound, sodium-containing compound, phosphorus-containing compound and sulfur-doped derived carbon balls in step S3 is 4-6:3-5:1-3:2-4:10-15:13-16:40-45:18-20.

[0017] Beneficial effects of the present invention: The invention provides a medium and trace element fertilizer specially used for flue-cured tobacco and a preparation method thereof. The invention compounds a medium element compound and a trace element compound, wherein phosphorus-containing compounds, potassium-containing compounds and the like can effectively supplement the nutrients required in the growth and development of flue-cured tobacco, solves the element deficiency of flue-cured tobacco, promotes the accumulation of dry matter and mature yellowing of flue-cured tobacco leaves, wherein copper-containing compounds and zinc-containing compounds can regulate the growth and development of flue-cured tobacco, enhance the passivation effect on viruses, thereby improving the disease resistance of flue-cured tobacco, reducing the loss caused by flue-cured tobacco diseases, and further increasing the yield of flue-cured tobacco.

[0018] The present invention provides a medium and trace element fertilizer specially used for flue-cured tobacco and a preparation method thereof. The limestone in the calcium-containing compound provided by the present invention is compounded with other substances to adjust the pH value of the soil. In addition, the fertilizer can also alleviate soil pollution to a certain extent, so that the soil can release nutrients to the maximum extent, thereby better nourishing the flue-cured tobacco.

[0019] The invention provides a medium and trace element fertilizer specially used for flue-cured tobacco and a preparation method thereof. The invention comprises the following steps: mixing sulfur-doped derivative carbon balls A and sulfur-doped derivative carbon balls B in a specific ratio, wherein the cavities contained therein can be used to load part of small molecule compounds, and compound with free small molecule compounds in the system for synergistic enhancement; since the pore sizes and porosities of the sulfur-doped derivative carbon balls A and B subjected to different carbonization temperatures are different, the release path of the small molecule compounds is extended to a certain length; compared with the traditional coated slow-release and controlled-release fertilizers in the prior art, the method avoids the introduction of coating materials, thereby effectively reducing the adverse effects of coating materials on soil and flue-cured tobacco crops, and achieving a long-lasting and long-lasting effect even without coating the fertilizers; therefore, the method has broad application prospects. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0021] Embodiment 1: A method for preparing a medium and trace element fertilizer for flue-cured tobacco, comprising the following steps: S1. Mix 90 mL of formic acid and 15 mL of 25% hydrogen peroxide solution, and ultrasonically vibrate for 12 min to obtain a mixed solution A; S2. The lignite is pretreated, coarsely ground and sieved, and the coal powder with a particle size of less than 0.074 mm is ball-milled for 5 hours to obtain coal powder; S3. 1.8 g of coal powder was added to 105 mL of mixed solution A, and the mixture was refluxed at 75 ° C for 160 min. The reaction mixture was filtered with a 0.4 μm microporous filter membrane to remove insoluble fragments, and the filtered solution was dialyzed to neutrality with a dialysis bag with a molecular weight cutoff of 80 Da to obtain a carbon quantum dot solution; S4. 0.4 g of magnesium citrate, 0.4 g of magnesium sulfate and 145 mL of a 3 mg / mL carbon quantum dot solution were mixed and stirred at 75 ° C for 10 h, and then dried in an oven at 75 ° C to obtain a solid powder; S5. The solid powder was ground in a mortar for 5 min, and then carbonized in a tube furnace. The temperature was raised from room temperature to 580 °C at a heating rate of 1.5 °C / min and kept for 50 min. After cooling to room temperature, the solid was immersed in a 2 mol / L hydrochloric acid solution to remove impurities. The mixed solution was then filtered. After the filtrate was neutral, the solid was dried in an oven at 95 °C to obtain sulfur-doped derivative carbon balls A. S6. 0.4 g of magnesium citrate, 0.4 g of magnesium sulfate and 145 mL of a 3 mg / mL carbon quantum dot solution were mixed and stirred at 75 ° C for 10 h, and then dried in an oven at 75 ° C to obtain a solid powder; S7. The solid powder was ground in a mortar for 5 minutes, and then carbonized in a tube furnace. The temperature was raised and kept at 580°C at a heating rate of 1.5°C / min for 50 minutes, then raised to 680°C for 50 minutes, and finally raised to 780°C for 50 minutes. After cooling to room temperature, the solid was immersed in a 2 mol / L hydrochloric acid solution to remove impurities. The mixed solution was then filtered. After the filtrate was neutral, the solid was dried in an oven at 95°C to obtain sulfur-doped derivative carbon balls B. S9. 2 g of sulfur-doped derived carbon balls A and 1 g of sulfur-doped derived carbon balls B were mixed to obtain sulfur-doped derived carbon balls; S10. 12 g of magnesium sulfate and 8 g of magnesium sulfate heptahydrate were mixed to obtain a magnesium-containing compound; S11. 10 g of EDTA chelated calcium and 20 g of limestone were mixed to obtain a calcium-containing compound; S12. Mixing 20 g of a magnesium-containing compound, 20 g of a calcium-containing compound and 8 g of sodium silicate to obtain a medium element complex; S13. 4 g of copper sulfate, 3 g of zinc sulfate, 1 g of boric acid, 2 g of manganese sulfate monohydrate, 10 g of potassium dihydrogen phosphate, 13 g of sodium molybdate, 40 g of phosphoric acid and 18 g of sulfur-doped carbon balls were mixed to obtain a trace element complex; Step S4. Dissolve 12 g of the medium element complex, 8 g of the trace element complex, 1 g of sophorolipid, 0.04 g of 2-amino-3-methylhexanoic acid, and 2 g of anhydrous citric acid in 85.5 g of deionized water, stir evenly, and obtain a medium and trace element fertilizer specifically for flue-cured tobacco.

[0022] Embodiment 2: A method for preparing a medium and trace element fertilizer for flue-cured tobacco, comprising the following steps: S1. Mix 95 mL of formic acid and 18 mL of 28% hydrogen peroxide, and ultrasonically vibrate for 13 min to obtain a mixed solution A; S2. The lignite was pretreated, coarsely ground and sieved, and the coal powder with a particle size of <0.074 mm was ball-milled for 5.5 hours to obtain coal powder; S3. 1.9 g of coal powder was added to 115 mL of mixed solution A, and the mixture was refluxed at 76 ° C for 165 min. The reaction mixture was filtered with a 0.5 μm microporous filter membrane to remove insoluble fragments, and the filtered solution was dialyzed to neutrality with a dialysis bag with a molecular weight cutoff of 850 Da to obtain a carbon quantum dot solution; S4. 0.5 g of magnesium citrate, 0.5 g of magnesium sulfate and 148 mL of a 4 mg / mL carbon quantum dot solution were mixed and stirred at 78 ° C for 11 h, and then dried in an oven at 78 ° C to obtain a solid powder; S5. The solid powder was ground in a mortar for 6 minutes, and then carbonized in a tube furnace. The temperature was raised from room temperature to 585°C at a heating rate of 1.6°C / min and kept at this temperature for 52 minutes. After cooling to room temperature, the solid was immersed in a 3 mol / L hydrochloric acid solution to remove impurities. The mixed solution was then filtered. After the filtrate was neutral, the solid was dried in an oven at 98°C to obtain sulfur-doped derivative carbon balls A. S6. 0.5 g of magnesium citrate, 0.5 g of magnesium sulfate and 148 mL of a 4 mg / mL carbon quantum dot solution were mixed and stirred at 78 ° C for 11 h, and then dried in an oven at 78 ° C to obtain a solid powder; S7. The solid powder was ground in a mortar for 6 minutes, and then carbonized in a tube furnace. The temperature was raised and kept at 585°C at a heating rate of 1.6°C / min for 52 minutes, then raised to 685°C for 52 minutes, and finally raised to 785°C for 52 minutes. After cooling to room temperature, the solid was immersed in a 3 mol / L hydrochloric acid solution to remove impurities. The mixed solution was then filtered. After the filtrate was neutral, the solid was dried in an oven at 98°C to obtain sulfur-doped derivative carbon balls B. S9. 3 g of sulfur-doped derived carbon balls A and 1.1 g of sulfur-doped derived carbon balls B were mixed to obtain sulfur-doped derived carbon balls; S10. 13 g of magnesium sulfate and 9 g of magnesium sulfate heptahydrate were mixed to obtain a magnesium-containing compound; S11. Mix 11 g of EDTA chelated calcium and 21 g of limestone to obtain a calcium-containing compound; S12. Mixing 22 g of a magnesium-containing compound, 22 g of a calcium-containing compound and 8.5 g of sodium silicate to obtain a medium element complex; S13. 4.5 g of copper sulfate, 3.5 g of zinc sulfate, 1.5 g of boric acid, 2.5 g of manganese sulfate monohydrate, 11 g of potassium dihydrogen phosphate, 14 g of sodium molybdate, 41 g of phosphoric acid and 18.5 g of sulfur-doped derived carbon balls were mixed to obtain a trace element complex; Step S4. Dissolve 13 g of the medium element complex, 9 g of the trace element complex, 1.2 g of sophorolipid, 0.05 g of 2-amino-3-methylhexanoic acid, and 2.5 g of anhydrous citric acid in 88 g of deionized water, stir evenly, and obtain a medium and trace element fertilizer for flue-cured tobacco.

[0023] Embodiment 3: A method for preparing a medium and trace element fertilizer for flue-cured tobacco, comprising the following steps: S1. Mix 100 mL of formic acid and 20 mL of 30% hydrogen peroxide solution, and ultrasonically vibrate for 13 min to obtain a mixed solution A; S2. The lignite is pretreated, coarsely ground and sieved, and the coal powder with a particle size of less than 0.074 mm is ball-milled for 6 hours to obtain coal powder; S3. 2 g of coal powder was added to 120 mL of mixed solution A, and the mixture was refluxed at 78 ° C for 170 min. The reaction mixture was filtered with a 0.4 μm microporous filter membrane to remove insoluble fragments, and the filtered solution was dialyzed to neutrality with a dialysis bag with a molecular weight cutoff of 90 Da to obtain a carbon quantum dot solution; S4. 0.6 g of magnesium citrate, 0.6 g of magnesium sulfate and 150 mL of a 5 mg / mL carbon quantum dot solution were mixed and stirred at 80 ° C for 12 h, and then dried in an oven at 80 ° C to obtain a solid powder; S5. The solid powder was ground in a mortar for 7 minutes, and then carbonized in a tube furnace. The temperature was raised from room temperature to 590°C at a heating rate of 1.8°C / min and kept for 55 minutes. After cooling to room temperature, it was immersed in a 4 mol / L hydrochloric acid solution to remove impurities. The mixed solution was then filtered. After the filtrate was neutral, the obtained solid was placed in an oven at 100°C to dry to obtain sulfur-doped derivative carbon balls A. S6. 0.6 g of magnesium citrate, 0.6 g of magnesium sulfate and 150 mL of a 5 mg / mL carbon quantum dot solution were mixed, stirred at 80 ° C for 12 h, and then dried in an oven at 80 ° C to obtain a solid powder; S7. The solid powder was ground in a mortar for 7 minutes, and then carbonized in a tube furnace. The temperature was raised and kept at 590°C at a heating rate of 1.8°C / min for 55 minutes, then raised to 690°C for 55 minutes, and finally raised to 790°C for 55 minutes. After cooling to room temperature, the powder was immersed in a 4 mol / L hydrochloric acid solution to remove impurities. The mixed solution was then filtered. After the filtrate was neutral, the obtained solid was placed in an oven at 100°C for drying to obtain sulfur-doped derivative carbon balls B. S9. 4 g of sulfur-doped derived carbon balls A and 1.2 g of sulfur-doped derived carbon balls B were mixed to obtain sulfur-doped derived carbon balls; S10. Mix 14 g of magnesium sulfate and 10 g of magnesium sulfate heptahydrate to obtain a magnesium-containing compound; S11. 12 g of EDTA chelated calcium and 22 g of limestone were mixed to obtain a calcium-containing compound; S12. Mixing 23 g of a magnesium-containing compound, 23 g of a calcium-containing compound and 9 g of sodium silicate to obtain a medium element complex; S13. 5 g of copper sulfate, 4 g of zinc sulfate, 2 g of boric acid, 3 g of manganese sulfate monohydrate, 12 g of potassium dihydrogen phosphate, 15 g of sodium molybdate, 42 g of phosphoric acid and 19 g of sulfur-doped carbon balls were mixed to obtain a trace element complex; Step S4. Dissolve 15 g of the medium element complex, 10 g of the trace element complex, 1.3 g of sophorolipid, 0.06 g of 2-amino-3-methylhexanoic acid, and 3 g of anhydrous citric acid in 90 g of deionized water, stir evenly, and obtain a medium and trace element fertilizer specifically for flue-cured tobacco.

[0024] Embodiment 4: A method for preparing a medium and trace element fertilizer for flue-cured tobacco, comprising the following steps: S1. Mix 105 mL of formic acid and 22 mL of 32% hydrogen peroxide, and ultrasonically vibrate for 14 min to obtain a mixed solution A; S2. The lignite is pretreated, coarsely ground and sieved, and the coal powder with a particle size of less than 0.074 mm is ball-milled for 5 hours to obtain coal powder; S3. 2.1 g of coal powder was added to 125 mL of mixed solution A, and the mixture was refluxed at 79 ° C for 175 min. The reaction mixture was filtered with a 0.5 μm microporous filter membrane to remove insoluble fragments, and the filtered solution was dialyzed to neutrality with a dialysis bag with a molecular weight cutoff of 95 Da to obtain a carbon quantum dot solution; S4. 0.7 g of magnesium citrate, 0.7 g of magnesium sulfate and 152 mL of a 3 mg / mL carbon quantum dot solution were mixed uniformly, stirred at 82 ° C for 10 h, and then placed in an oven at 82 ° C to obtain a solid powder; S5. The solid powder was ground in a mortar for 5 min, and then carbonized in a tube furnace. The temperature was raised from room temperature to 595 °C at a heating rate of 1.9 °C / min and kept at this temperature for 58 min. After cooling to room temperature, the solid was immersed in a 2 mol / L hydrochloric acid solution to remove impurities. The mixed solution was then filtered. After the filtrate was neutral, the obtained solid was placed in an oven at 102 °C and dried to obtain sulfur-doped derivative carbon balls A. S6. 0.7 g of magnesium citrate, 0.7 g of magnesium sulfate and 152 mL of a 3 mg / mL carbon quantum dot solution were mixed uniformly, stirred at 82 ° C for 10 h, and then placed in an oven at 82 ° C to obtain a solid powder; S7. The solid powder was ground in a mortar for 5 minutes, and then carbonized in a tube furnace. The temperature was raised and kept at 595°C at a heating rate of 1.9°C / min for 58 minutes, then raised to 695°C for 58 minutes, and finally raised to 795°C for 58 minutes. After cooling to room temperature, the mixture was immersed in a 2 mol / L hydrochloric acid solution to remove impurities. The mixed solution was then filtered. After the filtrate was neutral, the obtained solid was placed in an oven at 102°C for drying to obtain sulfur-doped derivative carbon balls B. S9. 5 g of sulfur-doped derived carbon balls A and 1.3 g of sulfur-doped derived carbon balls B were mixed to obtain sulfur-doped derived carbon balls; S10. 15 g of magnesium sulfate and 11 g of magnesium sulfate heptahydrate were mixed to obtain a magnesium-containing compound; S11. 13 g of EDTA chelated calcium and 23 g of limestone were mixed to obtain a calcium-containing compound; S12. Mixing 24 g of a magnesium-containing compound, 24 g of a calcium-containing compound and 9.5 g of sodium silicate to obtain a medium element complex; S13. 5.5 g of copper sulfate, 4.5 g of zinc sulfate, 2.5 g of boric acid, 3.5 g of manganese sulfate monohydrate, 13 g of potassium dihydrogen phosphate, 15.5 g of sodium molybdate, 43 g of phosphoric acid and 19.5 g of sulfur-doped derived carbon balls were mixed to obtain a trace element complex; Step S4. Dissolve 16 g of the medium element complex, 10.5 g of the trace element complex, 1.4 g of sophorolipid, 0.07 g of 2-amino-3-methylhexanoic acid, and 3.5 g of anhydrous citric acid in 92 g of deionized water, stir evenly, and obtain a medium and trace element fertilizer for flue-cured tobacco.

[0025] Embodiment 5: A method for preparing a medium and trace element fertilizer for flue-cured tobacco, comprising the following steps: S1. Mix 110 mL of formic acid and 25 mL of 35% hydrogen peroxide, and ultrasonically vibrate for 15 min to obtain a mixed solution A; S2. The lignite is pretreated, coarsely ground and sieved, and the coal powder with a particle size of less than 0.074 mm is ball-milled for 6 hours to obtain coal powder; S3. 2.2 g of coal powder was added to 135 mL of mixed solution A, and the mixture was refluxed at 80 ° C for 180 min. The reaction mixture was filtered with a 0.5 μm microporous filter membrane to remove insoluble fragments, and the filtered solution was dialyzed to neutrality with a dialysis bag with a molecular weight cutoff of 100 Da to obtain a carbon quantum dot solution; S4. 0.8 g of magnesium citrate, 0.8 g of magnesium sulfate and 155 mL of a 5 mg / mL carbon quantum dot solution were mixed and stirred at 85 ° C for 12 h, and then placed in an oven at 85 ° C to obtain a solid powder; S5. The solid powder was ground in a mortar for 7 minutes, and then carbonized in a tube furnace. The temperature was raised from room temperature to 600°C at a heating rate of 2°C / min for 60 minutes. After cooling to room temperature, the solid was immersed in a 4 mol / L hydrochloric acid solution to remove impurities. The mixed solution was then filtered. After the filtrate was neutral, the solid was dried in an oven at 105°C to obtain sulfur-doped derivative carbon balls A. S6. 0.8 g of magnesium citrate, 0.8 g of magnesium sulfate and 155 mL of a 5 mg / mL carbon quantum dot solution were mixed, stirred at 85 ° C for 12 h, and then placed in an oven at 85 ° C to obtain a solid powder; S7. The solid powder was ground in a mortar for 7 minutes, and then carbonized in a tube furnace. The temperature was raised and kept at 600°C at a heating rate of 2°C / min for 60 minutes, then raised to 700°C for 60 minutes, and finally raised to 800°C for 60 minutes. After cooling to room temperature, the solid was immersed in a 4 mol / L hydrochloric acid solution to remove impurities. The mixed solution was then filtered. After the filtrate was neutral, the solid was dried in an oven at 105°C to obtain sulfur-doped derivative carbon balls B. S9. 6 g of sulfur-doped derived carbon balls A and 1.5 g of sulfur-doped derived carbon balls B were mixed to obtain sulfur-doped derived carbon balls; S10. Mix 16 g of magnesium sulfate and 12 g of magnesium sulfate heptahydrate to obtain a magnesium-containing compound; S11. 15 g of EDTA chelated calcium and 25 g of limestone were mixed to obtain a calcium-containing compound; S12. Mixing 25 g of a magnesium-containing compound, 25 g of a calcium-containing compound and 10 g of sodium silicate to obtain a medium element complex; S13. 6 g of copper sulfate, 5 g of zinc sulfate, 3 g of boric acid, 4 g of manganese sulfate monohydrate, 15 g of potassium dihydrogen phosphate, 16 g of sodium molybdate, 45 g of phosphoric acid and 20 g of sulfur-doped derived carbon balls were mixed to obtain a trace element complex; Step S4. Dissolve 18 g of the medium element complex, 11 g of the trace element complex, 1.5 g of sophorolipid, 0.08 g of 2-amino-3-methylhexanoic acid, and 4 g of anhydrous citric acid in 93 g of deionized water, stir evenly, and obtain a medium and trace element fertilizer for flue-cured tobacco.

[0026] Comparative Example 1: Compared with Example 1, this comparative example does not add sulfur-derived carbon balls during the preparation of the special medium and trace element fertilizer for flue-cured tobacco. The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, the special medium and trace element fertilizer for flue-cured tobacco is obtained.

[0027] Comparative Example 2: Compared with Example 1, this comparative example does not add sulfur-doped derivative carbon balls A during the preparation of the medium and trace element fertilizer for flue-cured tobacco. The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, the medium and trace element fertilizer for flue-cured tobacco is obtained.

[0028] Comparative Example 3: Compared with Example 1, this comparative example does not add sulfur-doped derivative carbon balls B during the preparation of the medium and trace element fertilizer for flue-cured tobacco. The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, the medium and trace element fertilizer for flue-cured tobacco is obtained.

[0029] Comparative Example 4: Compared with Example 1, this comparative example only adjusts the amount of sulfur-doped derivative carbon balls A from "2g" to "1g", and the remaining steps and parameters are the same, which will not be repeated in this comparative example. Finally, a medium and trace element fertilizer specially used for flue-cured tobacco is obtained.

[0030] Comparative Example 5: Compared with Example 1, this comparative example does not add limestone during the preparation of the medium and trace element fertilizer for flue-cured tobacco, and the remaining steps and parameters are the same, which will not be repeated in this comparative example. Finally, the medium and trace element fertilizer for flue-cured tobacco is obtained.

[0031] Performance Testing: The special medium and trace element fertilizers for flue-cured tobacco prepared in Examples 1 to 5 and Comparative Examples 1 to 5 were prepared into a concentration of 2%, and sprayed into the tobacco field 30 days after the flue-cured tobacco was transplanted, and the per-acre yield increment (kg / acre) of the fields sprayed with medium and trace elements and those not sprayed with medium and trace elements under the same conditions was recorded; Determine the content of chemical components in the flue-cured tobacco samples obtained by spraying the medium and trace element fertilizers specially prepared in Examples 1 to 5 and Comparative Examples 1 to 5 and record them; Under the same conditions, the reduction in the effective cadmium content per kilogram of soil after spraying the medium and trace element fertilizers prepared in Examples 1 to 5 and Comparative Examples 1 to 5 for flue-cured tobacco for 5 days, 10 days and without spraying was measured and recorded; The results are shown in Table 1 below: Table 1 Summary of experimental results in Example 1-Example 5 and Comparative Example 1-Comparative Example 5

[0032] Data Analysis: As can be seen from Table 1, the medium and trace element fertilizer specially prepared for flue-cured tobacco of the present invention can increase the yield of flue-cured tobacco to a greater extent and the total sugar and total nitrogen contents in the prepared flue-cured tobacco are higher. In addition, the cadmium content in the soil can be effectively reduced. This may be because the present invention compounds the medium element complex and the trace element complex, wherein the phosphorus-containing compound, the potassium-containing compound, etc. can effectively supplement the nutrients required in the growth and development of flue-cured tobacco, solves the element deficiency of flue-cured tobacco, promotes the accumulation of dry matter and mature yellowing of flue-cured tobacco leaves, wherein the copper-containing compound and the zinc-containing compound can regulate the growth and development of flue-cured tobacco, enhance the passivation effect on viruses, thereby improving the disease resistance of flue-cured tobacco, reducing the loss of flue-cured tobacco diseases, and thus increasing the yield of flue-cured tobacco; wherein the limestone in the calcium-containing compound is compounded with other substances to adjust the pH of the soil. In addition, it can also alleviate soil pollution to a certain extent, so that the soil can release nutrients to the maximum extent, thereby better nourishing the flue-cured tobacco. In addition, by mixing the sulfur-doped derivative carbon ball A and the sulfur-doped derivative carbon ball B in a specific proportion, the cavities contained therein can be used to load some small molecule compounds, and compound with the free small molecule compounds in the system for synergy. Since the pore size and porosity of the sulfur-doped derivative carbon ball A and the sulfur-doped derivative carbon ball B after different carbonization temperatures are different, the release path of the small molecule compounds is extended to a certain length. Compared with the traditional coated slow-release and controlled-release fertilizers in the prior art, this method avoids the introduction of coating materials, and can effectively reduce the adverse effects of coating materials on soil and flue-cured tobacco crops, and achieves a long-lasting and long-lasting effect even if the fertilizer is not coated.

[0033] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0034] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A medium and trace element fertilizer specially used for flue-cured tobacco, characterized in that: The invention comprises the following raw materials in parts by weight: 12-18 parts of a medium element complex, 8-11 parts of a trace element complex, 1-1.5 parts of a sophorolipid, 0.04-0.08 parts of 2-amino-3-methylhexanoic acid, 2-4 parts of anhydrous citric acid, and 85.5-93 parts of deionized water; The intermediate element complex is prepared from a magnesium-containing compound, a calcium-containing compound and a sodium-containing compound; The trace element complex is prepared from a copper-containing compound, a zinc-containing compound, a boron-containing compound, a manganese-containing compound, a potassium-containing compound, a sodium-containing compound, a phosphorus-containing compound and sulfur-doped derived carbon balls; The sulfur-doped derived carbon balls are obtained by mixing sulfur-doped derived carbon balls A and sulfur-doped derived carbon balls B in a mass ratio of 2-6:1-1.5; The sulfur-doped derived carbon balls A are obtained by reacting magnesium sulfate, magnesium citrate and a carbon quantum dot solution; The sulfur-doped derived carbon balls B are obtained by reacting magnesium sulfate, magnesium citrate and a carbon quantum dot solution.

2. The medium and trace element fertilizer for flue-cured tobacco according to claim 1, characterized in that: The preparation process of the sulfur-doped derived carbon ball A is as follows: Step A1. Mix magnesium citrate, magnesium sulfate and carbon quantum dot solution evenly, stir at 75-85°C for 10-12h, and then dry in an oven at 75-85°C to obtain a solid powder; Step A2. Grind the solid powder in a mortar for 5-7 minutes, then carbonize it in a tubular furnace, start heating and heat preservation treatment, then cool to room temperature and soak it in 2-4 mol / L hydrochloric acid solution, then filter the mixed solution, and when the filtrate is neutral, place the obtained solid in a 95-105°C oven to dry to obtain sulfur-doped derivative carbon balls A.

3. The special medium and trace element fertilizer for flue-cured tobacco according to claim 2, characterized in that: The dosage ratio of magnesium citrate, magnesium sulfate and carbon quantum dot solution in step A1 is 0.4-0.8 g: 0.4-0.8 g: 145-155 mL; The process of the heating and heat preservation treatment in step A2 is as follows: heating from room temperature to 580-600° C. at a heating rate of 1.5-2° C. / min and keeping the temperature for 50-60 min.

4. The special medium and trace element fertilizer for flue-cured tobacco according to claim 1, characterized in that: The preparation process of the sulfur-doped derived carbon ball B is as follows: Step B1. Mix the magnesium citrate, magnesium sulfate and carbon quantum dot solution evenly, stir at 75-85°C for 10-12h, and then dry in an oven at 75-85°C to obtain a solid powder; Step B2. Grind the solid powder in a mortar for 5-7 minutes, then carbonize it in a tubular furnace, start heating and heat preservation treatment, then cool to room temperature and soak it in 2-4 mol / L hydrochloric acid solution, then filter the mixed solution, and when the filtrate is neutral, place the obtained solid in a 95-105°C oven to dry to obtain sulfur-doped derivative carbon balls B.

5. The special medium and trace element fertilizer for flue-cured tobacco according to claim 4, characterized in that: The dosage ratio of magnesium citrate, magnesium sulfate and carbon quantum dot solution in step B1 is 0.4-0.8 g: 0.4-0.8 g: 145-155 mL.

6. The special medium and trace element fertilizer for flue-cured tobacco according to claim 4, characterized in that: The process of the heating and heat preservation treatment in step B2 is as follows: heating from room temperature to 580-600°C at a heating rate of 1.5-2°C / min and keeping warm for 50-60min, then heating to 680-700°C and keeping warm for 50-60min, and finally heating to 780-800°C and keeping warm for 50-60min.

7. The medium and trace element fertilizer for flue-cured tobacco according to claim 1, characterized in that: The concentration of the carbon quantum dot solution is 3-5 mg / mL; The preparation process of the carbon quantum dot solution is as follows: Step C1. Mix formic acid and hydrogen peroxide evenly, and ultrasonically vibrate for 12-15 minutes to obtain a mixed solution A; Step C2. pre-treating the lignite, coarsely grinding and sieving, taking the coal powder with a particle size of less than 0.074 mm and ball-milling it for 5-6 hours to obtain coal powder; Step C3. Add coal powder to mixed solution A, reflux at 75-80° C. for 160-180 min, filter the reaction mixture with a microporous filter membrane, and dialyze the filtered solution with a dialysis bag to neutrality to obtain a carbon quantum dot solution.

8. The special medium and trace element fertilizer for flue-cured tobacco according to claim 7, characterized in that: The volume ratio of formic acid to hydrogen peroxide in step C1 is 90-110:15-25; The volume concentration of hydrogen peroxide in step C1 is 25%-35%; The mass ratio of the coal powder to the mixed liquid A in step C3 is 1.8-2.2 g: 105-135 mL; The particle size of the microporous filter membrane in step C3 is 0.4-0.5 μm; The molecular weight cut-off of the dialysis bag in step C3 is 80-100 Da.

9. The special medium and trace element fertilizer for flue-cured tobacco according to claim 1, characterized in that: The copper-containing compound in the trace element complex is copper sulfate; The zinc compound in the trace element complex is zinc sulfate; The boron-containing compound in the trace element complex is boric acid; The manganese compound in the trace element complex is manganese sulfate monohydrate; The potassium compound in the trace element complex is potassium dihydrogen phosphate; The sodium compound in the trace element complex is sodium molybdate; The phosphorus-containing compound in the trace element complex is phosphoric acid; The magnesium compound in the middle element complex is obtained by mixing magnesium sulfate and magnesium sulfate heptahydrate in a mass ratio of 1.2-1.6:0.8-1.2; The calcium compound in the middle element complex is obtained by mixing EDTA chelated calcium and limestone in a mass ratio of 1-1.5:2-2.5; The sodium compound in the middle element complex is sodium silicate.

10. A method for preparing the medium and trace element fertilizer for flue-cured tobacco according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1. mixing a magnesium-containing compound, a calcium-containing compound and a sodium-containing compound to obtain a middle element complex; Step S2. mixing the sulfur-doped derived carbon balls A and the sulfur-doped derived carbon balls B to obtain sulfur-doped derived carbon balls; Step S3. mixing a copper-containing compound, a zinc-containing compound, a boron-containing compound, a manganese-containing compound, a potassium-containing compound, a sodium-containing compound, a phosphorus-containing compound and a sulfur-doped derived carbon ball to obtain a trace element complex; Step S4. dissolving the medium element complex, the trace element complex, sophorolipids, 2-amino-3-methylhexanoic acid, and anhydrous citric acid in deionized water, stirring evenly, to obtain a medium and trace element fertilizer for flue-cured tobacco; The mass ratio of the magnesium-containing compound, the calcium-containing compound and the sodium-containing compound in step S1 is 20-25:20-25:8-10; The mass ratio of the copper-containing compound, zinc-containing compound, boron-containing compound, manganese-containing compound, potassium-containing compound, sodium-containing compound, phosphorus-containing compound and sulfur-doped derived carbon balls in step S3 is 4-6:3-5:1-3:2-4:10-15:13-16:40-45:18-20.

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