Humic acid-based compound fertilizer, preparation method and application thereof

Abstract

This invention relates to the field of fertilizers, providing a humic acid-based compound fertilizer, its preparation method, and its application. By weight, the humic acid-based compound fertilizer comprises the following raw materials: 30-40 parts of potassium nitrohumate slurry, 15-25 parts of monoammonium phosphate, 15-20 parts of urea, 5-10 parts of potassium dihydrogen phosphate, 3-5 parts of trace element chelate solution, and 0.5-1 parts of sulfonate filtration reducer. The humic acid-based compound fertilizer provided by this invention solves the water solubility problem of traditional humic acid and has the advantage of complete nutrition. It can efficiently promote crop growth and is applicable to economic crops such as melons, fruits, vegetables, underground root crops, flowers, and medicinal herbs.

Description

Technical Field

[0001] This invention relates to the field of fertilizers, and in particular to a humic acid-based compound fertilizer, its preparation method, and its application. Background Technology

[0002] For a long time, while the use of chemical fertilizers has increased crop yields and incomes, its overuse has also led to numerous side effects such as soil compaction, salinization, decreased soil fertility, and environmental pollution. Humic acid is a class of natural high-molecular-weight organic compounds formed from plant and animal residues through microbial decomposition and geochemical processes. It is widely found in soils, peat, lignite, and weathered coal. In agriculture, humic acid has multiple functions, including improving soil structure, enhancing soil fertility, promoting crop growth, and strengthening crop resistance.

[0003] Although humic acid possesses many excellent characteristics, the biggest problem with natural humic acid is its poor water solubility, which severely limits its widespread application in agricultural production. To improve the water solubility of humic acid, existing technologies typically employ methods such as alkali dissolution, oxidation, and sulfonation to modify it. Compared to the other two methods, alkali dissolution causes less structural damage to humic acid and preserves its biological activity. However, the humates obtained by the traditional alkali dissolution process contain many impurities, reducing the effectiveness of the fertilizer. Furthermore, humic acid fertilizers prepared using existing technologies usually only contain humic acid and potassium, failing to simultaneously provide the complete nutrients such as nitrogen, phosphorus, and potassium required for crop growth.

[0004] Patent CN 101024590 B discloses a method for preparing a water-soluble fertilizer containing humic acid. The humic acid is prepared by using potassium humate instead of sodium humate, which avoids environmental pollution and also replenishes the soil with a large amount of potassium. The method for preparing the potassium humate solution involves adding water and raw materials containing humic acid to a slurry tank, adding potassium hydroxide as an extractant, maintaining the temperature at 50-60℃, slurry extraction for 1-2 hours, centrifuging in a centrifuge, and filtering out the potassium humate solution. However, this method is still a traditional alkaline dissolution process and does not solve the problem of impurities.

[0005] Therefore, there is an urgent need in the market for a humic acid-based compound fertilizer that solves the water solubility problem of traditional humic acid and has the advantage of complete nutrition, which can effectively promote crop growth. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention discloses a humic acid-based compound fertilizer. It uses potassium nitrohumate slurry as the main component, solving the water solubility problem of traditional humic acid. Furthermore, it is combined with monoammonium phosphate, urea, potassium dihydrogen phosphate, trace element chelate solution, and sulfonate filtration reducer, giving it the advantage of complete nutrition and enabling it to efficiently promote crop growth.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The present invention provides a humic acid-based compound fertilizer, which, by weight, comprises the following raw materials: 30-40 parts of potassium nitrohumate slurry, 15-25 parts of monoammonium phosphate, 15-20 parts of urea, 5-10 parts of potassium dihydrogen phosphate, 3-5 parts of trace element chelation solution, and 0.5-1 parts of sulfonate filtration loss reducer.

[0008] In some embodiments of the present invention, the method for preparing the potassium nitrohumate slurry includes the following steps: (1) Take lignite, crush it, sieve it, dry it, add 1.5-2.5 mol / L HCl aqueous solution, heat it, stir it, filter it, take the solid, wash it, add 1.5-2.5 mol / L HF aqueous solution, heat it, stir it, filter it, take the solid, wash it, dry it, and get product 1 for later use; (2) Take product 1 from step (1), add HNO3 aqueous solution, heat, stir, cool to room temperature, age, filter, take solid, wash, dry, and obtain product 2 for later use; (3) Take product 2 from step (2), add KOH aqueous solution, heat, stir, cool to room temperature, centrifuge, and take the liquid to obtain potassium nitrohumate slurry.

[0009] In step (3), the ratio of product 2 to KOH aqueous solution is 1g:(11-13)ml, and the concentration of KOH aqueous solution is 0.5-0.7mol / L.

[0010] In some embodiments of the present invention, in step (1), the ratio of lignite, HCl aqueous solution and HF aqueous solution is 1g:(3.5-4.5)ml:(4.5-5.5)ml.

[0011] Preferably, in step (1), the ratio of lignite, HCl aqueous solution and HF aqueous solution is 1g:4ml:5ml.

[0012] In some embodiments of the present invention, in step (2), the ratio of product 1 to HNO3 aqueous solution is 1g: (9.5-10.5)ml, wherein the concentration of HNO3 aqueous solution is 10-20wt%.

[0013] Preferably, in step (2), the ratio of product 1 to HNO3 aqueous solution is 1g:10ml, wherein the concentration of HNO3 aqueous solution is 15wt%.

[0014] Humic acid can promote fertilizer utilization, improve soil structure, and improve crop quality. However, natural humic acid contains many hydrophobic groups and has poor water solubility, which leads to a decrease in the absorption and utilization rate of crops and limits its functional effects. Potassium nitrohumate can break the chain of humic acid and turn it into water-soluble small molecules, which are widely used in the field of fertilizer.

[0015] To control costs and the nitro content of potassium nitrohumate, natural lignite is often chosen as the raw material for its extraction and preparation in industry. However, potassium nitrohumate prepared by traditional processes contains a large amount of impurities such as silicon, aluminum, calcium, and magnesium. These impurities can form precipitates with nutrients such as nitrogen, phosphorus, and potassium, reducing the effectiveness of the fertilizer. The applicant chose to pre-treat lignite by controlling the amount of acid and HF aqueous solution added to remove impurities and improve purity. Furthermore, the applicant controlled the nitration reaction conditions to increase the number of active groups in the potassium nitrohumate molecule and improve its water solubility. This improved the efficiency and stability of subsequent chelation with nitrogen, phosphorus, potassium, and trace elements, thereby enhancing the growth-promoting effect of humic acid compound fertilizer on crops.

[0016] In some embodiments of the present invention, the method for preparing the trace element chelate solution includes the following steps: Add EDTA to deionized water 1, stir, and set aside the liquid. Add the trace element mixture to deionized water 2, add the solution, stir, and you will get the trace element chelated solution. The ratio of EDTA to deionized water 1 is 1g: (9-11)ml; the ratio of trace element mixture to deionized water 2 is 1g: (4-5)ml; and the mass ratio of EDTA to trace element mixture is 1: (2.5-3).

[0017] In some embodiments of the present invention, the trace element mixture comprises ZnSO4·7H2O, FeSO4·7H2O, CuSO4·5H2O, and (NH4)6Mo7O. 24 It is composed of 4H2O and Na2B4O7·10H2O.

[0018] In some embodiments of the present invention, the trace element mixture contains ZnSO4·7H2O, FeSO4·7H2O, CuSO4·5H2O, and (NH4)6Mo7O. 24 The mass ratio of ·4H2O and Na2B4O7·10H2O is 1:(0.8-1):(0.7-9):(0.35-0.5):(0.6-0.8).

[0019] In some embodiments of the present invention, the sulfonate filtration reducer is sodium lignosulfonate.

[0020] In another aspect, this invention provides a method for preparing a humic acid-based compound fertilizer, comprising the following steps: Add sulfonate filtration reducer to nitrohumate slurry, stir, heat to 55-65℃, and add monoammonium phosphate, urea, and potassium dihydrogen phosphate in sequence while stirring. Add trace element chelation solution, stir, filter, and age to obtain humic acid-based compound fertilizer.

[0021] In another aspect, this invention provides an application of humic acid-based compound fertilizer, which can be applied to fruits, vegetables, underground root crops, flowers, and medicinal herbs.

[0022] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention discloses a humic acid-based compound fertilizer, which uses potassium nitrohumate slurry as the main component, thus solving the water solubility problem of traditional humic acid. It is combined with monoammonium phosphate, urea, potassium dihydrogen phosphate, trace element chelate solution and sulfonate filtration reduction agent. Through the synergistic effect between the components, it has the advantages of complete nutrition and can efficiently promote crop growth.

[0023] (2) The present invention designs and prepares a potassium nitrohumate slurry. The applicant selects to control the amount of acid and HF aqueous solution added to pre-treat lignite to remove impurities and improve purity. Furthermore, the nitration reaction conditions are controlled to increase the number of active groups in the potassium nitrohumate molecule and improve its water solubility, thereby improving the efficiency and stability of subsequent chelation with nitrogen, phosphorus, potassium and trace elements, and thus making the humic acid compound fertilizer have a better effect on promoting crop growth. Detailed Implementation

[0024] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0025] In the following examples and comparative examples, except for the potassium nitrohumate slurry and the trace element chelation solution, all other compound monomers and related reagents used were commercially available.

[0026] Preparation Example 1 The synthesis method of potassium nitrohumate slurry A includes the following steps: (1) Take 50g of lignite, crush it, pass it through a 100-mesh sieve, dry it at 80℃ for 24h, add 200ml of 2mol / L HCl aqueous solution, heat it to 60℃, stir it for 8h, filter it, take the solid, wash it with deionized water until the filtrate is tested with 0.1mol / L AgNO3 aqueous solution until no precipitate is produced, add 250ml of 2mol / L HF aqueous solution, heat it to 60℃, stir it for 24h, filter it, take the solid, wash it with deionized water until the filtrate is tested with 0.1mol / L CaCl2 aqueous solution until no precipitate is produced, dry the solid at 80℃ for 24h to obtain product 1 for later use; (2) Take 10g of product 1 from step (1), add 100ml of 15wt% HNO3 aqueous solution, heat to 60℃, stir for 1h, cool to room temperature, age for 24h, filter, take the solid, wash with deionized water until the pH of the filtrate is 7, dry the solid at 80℃ for 24h, and obtain product 2 for later use. (3) Take 5g of product 2 from step (2), add 60ml of 0.6mol / L KOH aqueous solution, heat to 80℃, stir for 1h, cool to room temperature, centrifuge, and take the liquid to obtain potassium nitrohumate slurry A.

[0027] Preparation Example 2 Potassium nitrohumate slurry B is implemented in the same way as potassium nitrohumate slurry A, except that the volume of the HCl aqueous solution in step (1) is replaced with 30 ml.

[0028] Preparation Example 3 Potassium nitrohumate slurry C is implemented in the same way as potassium nitrohumate slurry A, except that the volume of the HF aqueous solution in step (1) is replaced with 40 ml.

[0029] Preparation Example 4 Potassium nitrohumate slurry D is implemented in the same way as potassium nitrohumate slurry A, except that the volume of HNO3 aqueous solution in step (2) is replaced with 90 ml.

[0030] Preparation Example 5 The synthesis method of potassium nitrohumate slurry E includes the following steps: (1) Take 10g of lignite, crush it, pass it through a 100-mesh sieve, dry it at 80℃ for 24h, add 100ml of 15wt% HNO3 aqueous solution, heat it to 60℃, stir it for 1h, cool it to room temperature, age it for 24h, filter it, take the solid, wash it with deionized water until the pH of the filtrate is 7, dry it at 80℃ for 24h, and obtain the product for later use. (3) Take 5g of the product from step (2), add 60ml of 0.6mol / L KOH aqueous solution, heat to 80℃, stir for 1h, cool to room temperature, centrifuge, and take the liquid to obtain potassium nitrohumate slurry E.

[0031] Preparation Example 6 The method for synthesizing trace element chelate solutions includes the following steps: Add 4g EDTA to 40ml of deionized water at 40℃ and stir until completely dissolved to obtain a liquid for later use. Add 2.8g ZnSO4·7H2O, 2.7g FeSO4·7H2O, 2.5g CuSO4·5H2O, and 1.2g (NH4)6Mo7O 24 Add 4H2O and 2g Na2B4O7·10H2O to 50ml of deionized water, add liquid, stir well, and you will get a trace element chelate solution.

[0032] Example 1 A humic acid-based compound fertilizer, by weight, comprises the following raw materials: 35 parts of potassium nitrohumate slurry A, 20 parts of monoammonium phosphate, 18 parts of urea, 7 parts of potassium dihydrogen phosphate, 4 parts of trace element chelation solution, and 0.8 parts of sodium lignosulfonate.

[0033] The preparation method of humic acid-based compound fertilizer in this embodiment includes the following steps: Add sodium lignosulfonate to nitrohumate slurry A, stir for 30 minutes, heat to 60°C, add monoammonium phosphate, urea, and potassium dihydrogen phosphate in sequence while stirring, add trace element chelation solution, stir for 30 minutes, filter, and age for 24 hours to obtain humic acid-based compound fertilizer.

[0034] Example 2 A humic acid-based compound fertilizer, by weight, comprises the following raw materials: 30 parts of potassium nitrohumate slurry A, 15 parts of monoammonium phosphate, 15 parts of urea, 5 parts of potassium dihydrogen phosphate, 3 parts of trace element chelation solution, and 0.5 parts of sodium lignosulfonate.

[0035] The preparation method of humic acid-based compound fertilizer in this embodiment includes the following steps: Add sodium lignosulfonate to nitrohumate slurry A, stir for 30 minutes, heat to 55°C, and add monoammonium phosphate, urea, and potassium dihydrogen phosphate in sequence while stirring. Add trace element chelation solution, stir for 30 minutes, filter, and age for 24 hours to obtain humic acid-based compound fertilizer.

[0036] Example 3 A humic acid-based compound fertilizer, by weight, comprises the following raw materials: 40 parts of potassium nitrohumate slurry A, 25 parts of monoammonium phosphate, 20 parts of urea, 10 parts of potassium dihydrogen phosphate, 5 parts of trace element chelate solution, and 1 part of sodium lignosulfonate.

[0037] The preparation method of the humic acid-based compound fertilizer in this embodiment is the same as that in Example 1.

[0038] Example 4 This embodiment provides a humic acid-based compound fertilizer and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that potassium nitrohumate slurry B replaces potassium nitrohumate slurry A in an equal amount.

[0039] Example 5 This embodiment provides a humic acid-based compound fertilizer and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that potassium nitrohumate slurry C is used to replace potassium nitrohumate slurry A in an equal amount.

[0040] Example 6 This embodiment provides a humic acid-based compound fertilizer and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that potassium nitrohumate slurry D is used to replace potassium nitrohumate slurry A in equal amounts.

[0041] Example 7 This embodiment provides a humic acid-based compound fertilizer and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that potassium nitrohumate slurry E is used to replace potassium nitrohumate slurry A in equal amounts.

[0042] Performance testing The relevant properties of the humic acid-based compound fertilizers in Examples 1-7 above were tested, and the test results are shown in Table 1.

[0043] 1. Water-soluble Add 10g of the humic acid-based compound fertilizer from Examples 1-7 to 100ml of deionized water (25℃), stir for 30min, and observe the degree of dissolution.

[0044] Table 1

[0045] As shown in Table 1, the humic acid-based compound fertilizers in Examples 1-3 of this invention all exhibit good water solubility. Specifically, Examples 4-5 involved altering the amounts of acid and HF aqueous solution added during the deashing pretreatment of lignite in the synthesis of potassium nitrohumate slurry; Example 6 involved changing the amount of nitric acid aqueous solution used in the synthesis of potassium nitrohumate slurry; and Example 7 involved preparing potassium nitrohumate slurry using conventional methods. Tests in all examples revealed a certain degree of decrease in the water solubility of the humic acid-based compound fertilizers.

[0046] A fertilization experiment was conducted to compare the humic acid-based compound fertilizer of Example 1. The test crop was cucumber. The experiment adopted a randomized block design. 4 mu of cucumbers were planted in the experimental field and randomly divided into 2 groups of 2 mu each. The humic acid-based compound fertilizer of Example 1 and the humic acid liquid fertilizer of the control group were used respectively. The control group used commercially available conventional humic acid liquid fertilizer (Xilezi product of Beijing Ruihetian Agricultural Technology Co., Ltd.). The fertilizer was diluted with water at a mass ratio of 1:500 and then sprayed evenly on the stems and leaves of cucumbers. The stems and leaves were sprayed once each at the seedling stage, the initial flowering stage, and the flowering and fruiting stage. The amount used each time was 5 kg per mu. The average yield of cucumbers per mu at harvest was calculated.

[0047] Table 1

[0048] As shown in Table 1, the cucumber yield per mu after application of the humic acid-based compound fertilizer in Example 1 of this invention was relatively high, significantly higher than that of the control group, indicating that it had a high promoting effect on crop growth.

[0049] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A humic acid-based compound fertilizer, characterized by, By weight, the humic acid-based compound fertilizer comprises the following raw materials: 30-40 parts of potassium nitrohumate slurry, 15-25 parts of monoammonium phosphate, 15-20 parts of urea, 5-10 parts of potassium dihydrogen phosphate, 3-5 parts of trace element chelation solution, and 0.5-1 parts of sulfonate filtration loss reducer.

2. The humic acid-based compound fertilizer according to claim 1, characterized in that, The preparation method of the potassium nitrohumate slurry includes the following steps: (1) Take lignite, crush it, sieve it, dry it, add 1.5-2.5 mol / L HCl aqueous solution, heat it, stir it, filter it, take the solid, wash it, add 1.5-2.5 mol / L HF aqueous solution, heat it, stir it, filter it, take the solid, wash it, dry it, and get product 1 for later use; (2) Take product 1 from step (1), add HNO3 aqueous solution, heat, stir, cool to room temperature, age, filter, take solid, wash, dry, and obtain product 2 for later use; (3) Take product 2 from step (2), add KOH aqueous solution, heat, stir, cool to room temperature, centrifuge, and take the liquid to obtain potassium nitrohumate slurry.

3. The humic acid-based compound fertilizer according to claim 2, characterized in that, In step (1), the ratio of lignite, HCl aqueous solution and HF aqueous solution is 1g: (3.5-4.5)ml: (4.5-5.5)ml.

4. The humic acid-based compound fertilizer according to claim 2, characterized in that, In step (2), the ratio of product 1 to HNO3 aqueous solution is 1g: (9.5-10.5)ml, wherein the concentration of HNO3 aqueous solution is 10-20wt%.

5. The humic acid-based compound fertilizer according to claim 1, characterized in that, The method for preparing the trace element chelate solution includes the following steps: Add EDTA to deionized water 1, stir, and set aside the liquid. Add the trace element mixture to deionized water 2, add the liquid, stir, and you will get the trace element chelate solution. The ratio of EDTA to deionized water 1 is 1g: (9-11)ml; the ratio of trace element mixture to deionized water 2 is 1g: (4-5)ml; and the mass ratio of EDTA to trace element mixture is 1: (2.5-3).

6. The humic acid-based compound fertilizer according to claim 5, characterized in that, The trace element mixture comprises ZnS04-7H20, FeS04-7H20, CuS04-5H20, (NH4)6Mo70 24 4H20 and Na2B4O7-10H20.

7. The humic acid-based compound fertilizer according to claim 6, characterized in that, The mass ratio of ZnS04*7H20, FeS04*7H20, CuS04*5H20, (NH4)6Mo70 24 4H20 and Na2B407*10H20 in the trace element mixture is 1:(0.8-1):(0.7-9):(0.35-0.5):(0.6-0.8).

8. The humic acid-based compound fertilizer as claimed in claim 1, characterized by, The sulfonate filtration reducer is sodium lignosulfonate.

9. A method of producing the humic acid-based compound fertilizer according to any one of claims 1 to 8, characterized by, Includes the following steps: Add sulfonate filtration reducer to nitrohumate slurry, stir, heat to 55-65℃, and add monoammonium phosphate, urea, and potassium dihydrogen phosphate in sequence while stirring. Add trace element chelation solution, stir, filter, and age to obtain humic acid-based compound fertilizer.

10. Use of the humic acid-based compound fertilizer according to any one of claims 1 to 8, characterized in that It can be applied to fruits, vegetables, underground root crops, flowers, and medicinal herbs.

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