Fulvic acid liquid water-soluble fertilizer for saline-alkali soil and preparation method of fulvic acid liquid water-soluble fertilizer

Abstract

The invention discloses a fulvic acid liquid water-soluble fertilizer for saline-alkali soil and a preparation method of the fulvic acid liquid water-soluble fertilizer. The fulvic acid liquid water-soluble fertilizer is prepared from 200-500 parts of humic acid mother liquor, 100-300 parts of bacillus velezensis concentrated solution, 30-60 parts of organic chelated trace element solution, 10-30 parts of solubilizing slow-release additive, 1-8 parts of anti-caking agent, 1-5 parts of stabilizer and the balance of purified water, wherein the total amount is 1000 parts. The preparation can be completely dissolved by adding water on site, and tedious pretreatment is not needed; thallus activity is high, and long-acting nitrogen fixation and phosphorus solubilization can be achieved; soil CEC can be improved, and Fe, Zn and other elements can be promoted to be absorbed by plant root systems; the soil conditioner can reduce the soil conductivity in a short term, improve the soil structure for a long term, promote crop growth and increase yield and quality; the process is simplified, the cost is low, one-time liquid formula production is achieved, high-energy-consumption links such as granulation and drying are avoided, and the method is suitable for large-scale industrial preparation.

Description

Technical Field

[0001] This invention relates to the field of soil conditioner technology, specifically to a humic acid liquid water-soluble fertilizer for saline-alkali land and its preparation method. Background Technology

[0002] Saline-alkali soil refers to soil where soluble salts accumulate under the combined effects of natural and anthropogenic factors, leading to increased soil ion concentration and osmotic pressure. This inhibits water absorption and extension by plant roots, and the high osmotic pressure also interferes with chloroplast protein synthesis, ultimately reducing crop yield and quality. Improving saline-alkali land requires a synergistic approach using physical, chemical, and biological methods. By adjusting soil structure, moisture conditions, and the gaseous environment, salt leaching and migration can be controlled.

[0003] In existing technologies, commonly used soil conditioners include gypsum, lime, humic acid, and biological agents: Humic acid modification—utilizing the efficient ion exchange, complexation, and adsorption capabilities of humic acid to loosen soil, regulate pH, and fix Na⁺ and Cl⁻ ions, but it is mostly applied as solid powder or granules. Solid humic acid powder / granules dissolve slowly, disperse poorly, have complex preparation processes, and are inconvenient for on-site use. Microbial modification—using nitrogen-fixing, phosphorus-solubilizing, and potassium-releasing strains (such as mycorrhizal fungi and Bacillus subtilis) to enhance soil nutrient cycling and improve plant resistance, but microbial agents are mostly freeze-dried powders or suspensions, easily deactivated during storage and transportation, resulting in insufficient viable bacteria counts and fluctuating effects after application. Humic acid + microbial compound—some patents report mixing solid humic acid powder with microbial powder for application, but drawbacks include difficulty in dispersing humic acid, mutual adsorption between powder and agent, or impaired resistance, affecting the function of the strains. While the above solutions can improve saline-alkali land to some extent, they often fail to meet the requirements of rapid dissolution of high concentrations, high bacterial activity, convenient on-site preparation, and low-cost production.

[0004] This invention combines humic acid liquid water-soluble fertilizer with Bacillus belesii suspension system, which has the adsorption and complexation function of humic acid and the nitrogen fixation and phosphorus solubilization ability of Bacillus belesii, to improve saline-alkali soil in the long term and promote healthy crop growth. The production process is simple and low-cost, making it suitable for large-scale industrial production. Summary of the Invention

[0005] The purpose of this invention is to provide a humic acid liquid water-soluble fertilizer for saline-alkali land and its preparation method.

[0006] To achieve the above objectives, the technical solution adopted by this invention is: a humic acid liquid water-soluble fertilizer for saline-alkali land, comprising, by weight: 200-500 parts of sodium humate mother liquor, 100-300 parts of Bacillus velezensis concentrate, 30-60 parts of organic chelated trace element solution, 10-30 parts of solubilizing and slow-release adjuvant, 1-8 parts of anti-caking agent, 1-5 parts of stabilizer, and purified water added to a total volume of 1000 parts; wherein, Bacillus velezensis has the preservation number: CGMCC No: 23398.

[0007] Preferably, the source of humic acid can be replaced with calcium humate, ammonium humate, or crude extract of natural humic acid.

[0008] Preferably, the humic acid content in the sodium humate mother liquor is ≥25g / L.

[0009] Preferably, the humic acid content in the sodium humate mother liquor is ≥30g / L.

[0010] Preferably, the viable count of the Bacillus berberis fermentation concentrate is ≥5×10⁻⁶. 8 CFU / mL.

[0011] Preferably, the viable count of the Bacillus vesiculosus fermentation concentrate is ≥1×10⁻⁶. 9 CFU / mL.

[0012] Preferably, the stability of Bacillus belye is as follows: after 30 days of storage at room temperature, there is no obvious stratification or a decrease in viable cells of <10%.

[0013] Preferably, the trace elements in the organic chelated trace element solution include Fe, Zn, and Mn, with the contents of Fe, Zn, and Mn being 2~5 g / L and the total amount of trace elements being ≥3 g / L.

[0014] Preferably, the organic chelated trace element solution can be replaced by humic acid chelated form or EDTA chelated form.

[0015] Preferably, the solubilizing and slow-release agent includes one or a combination of polyethylene glycol and propylene glycol.

[0016] Preferably, it also includes a pH adjuster to adjust the pH to 6.5-7.5.

[0017] Preferably, the pH adjuster comprises a mixture of citric acid and sodium bicarbonate.

[0018] Preferably, the stabilizer comprises propylene glycol or potassium sorbate, or a combination thereof.

[0019] Preferably, the anti-caking agent comprises a polymeric silicate. The *Bacillus belyceae* strain involved in this application is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No: 23398, deposited on September 13, 2021, at the Institute of Microbiology, Chinese Academy of Sciences, No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing. Its systematic classification is *Bacillus belyceae*. Bacillus velezensis .

[0020] This application also claims a method for preparing a fulvic acid liquid water-soluble fertilizer for saline-alkali land, used to prepare the aforementioned fulvic acid liquid water-soluble fertilizer for saline-alkali land, comprising the following steps: (1) Preparation of sodium humate mother liquor: Humic acid powder was slowly dissolved in purified water at 60℃ by stirring, and then filtered to remove impurities; (2) Bacterial liquid concentration: Bacillus berleis was cultured in a continuous fermenter and then concentrated to the target viable count after harvesting via microfiltration membrane; (3) Mixing and homogenizing: Add humic acid mother liquor, organic chelating element solution and solubilizing agent in sequence, and stir; (4) Inoculation stability: At 30°C, slowly add Bacillus vesiculus concentrate and stir with low shear; (5) Final preparation and packaging: Add pH adjuster, anti-caking agent and preservative, mix evenly, and package into plastic buckets or soft packaging bags.

[0021] Preferably, in step (4), the inoculation process can employ cold shock or microencapsulation technology to improve the survival rate of the bacteria.

[0022] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: 1. This invention utilizes the synergistic effect of humic acid mother liquor and solubilizer, allowing for complete dissolution upon on-site addition of water, eliminating the need for cumbersome pretreatment; low-shear inoculation and a preservative-stabilizing formula ensure ≥5×10 8 CFU / mL live bacteria, long-lasting nitrogen fixation and phosphorus solubilization, with high bacterial activity; through the synergistic effect of humic acid and organic chelated trace elements, it enhances the soil CEC (cation exchange capacity) and promotes the absorption of elements such as Fe and Zn by plant roots. 2. This invention can reduce soil electrical conductivity in the short term and improve soil structure in the long term, promoting crop growth, increasing yield and quality; the process is simplified and the cost is low: it is produced by a one-time liquid formula without high-energy-consuming steps such as granulation and drying, making it suitable for large-scale industrial preparation. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1 300 parts of sodium humate mother liquor, 200 parts of Bacillus velezensis concentrate, 50 parts of organic chelated trace element solution, 20 parts of solubilizing and slow-release agent, 5 parts of anti-caking agent, 2 parts of stabilizer, and purified water added to a total of 1000 parts; among which, Bacillus velezensis, preservation number: CGMCC No: 23398.

[0025] Preferably, the source of humic acid can be replaced with calcium humate, ammonium humate, or crude extract of natural humic acid.

[0026] Preferably, the humic acid content in the sodium humate mother liquor is ≥30g / L.

[0027] Preferably, the viable count of the Bacillus vesiculosus fermentation concentrate is ≥1×10⁻⁶. 9 CFU / mL.

[0028] Preferably, the stability of Bacillus belye is as follows: after 30 days of storage at room temperature, there is no obvious stratification or a decrease in viable cells of <10%.

[0029] Preferably, the trace elements in the organic chelated trace element solution include Fe, Zn, and Mn, with the contents of Fe, Zn, and Mn being 2~5 g / L and the total amount of trace elements being ≥3 g / L.

[0030] Preferably, the solubilizing and slow-release agent includes polyethylene glycol and propylene glycol.

[0031] Preferably, it also includes a pH adjuster to adjust the pH to 6.5-7.5.

[0032] Preferably, the pH adjuster comprises a mixture of citric acid and sodium bicarbonate.

[0033] Preferably, the stabilizer includes propylene glycol and potassium sorbate.

[0034] Preferably, the anti-caking agent comprises a polymeric silicate.

[0035] The preparation method of the above-mentioned humic acid liquid water-soluble fertilizer for saline-alkali land includes the following steps: (1) Preparation of sodium humate mother liquor: Humic acid powder was slowly dissolved in purified water at 60℃ by stirring, and then filtered to remove impurities; (2) Bacterial liquid concentration: Bacillus berleis was cultured in a continuous fermenter and then concentrated to the target viable count after harvesting via microfiltration membrane; (3) Mixing and homogenizing: Add humic acid mother liquor, organic chelated element solution and solubilizing agent in sequence, and stir for 30 min; (4) Inoculation stability: At 30°C, slowly add Bacillus belye concentrated solution and stir at low shear for 30 min; (5) Final preparation and packaging: Add pH adjuster, anti-caking agent and preservative, mix evenly, and package into plastic buckets or soft packaging bags.

[0036] Example 2 This embodiment is based on the above embodiment 1, and the similarities with the above embodiment will not be repeated.

[0037] This embodiment relates to determining the effect of humic acid liquid water-soluble fertilizer on the electrical conductivity (EC) of saline-alkali soil.

[0038] In this embodiment, four processing methods are set, including: (1) Control group: water treatment; (2) 500 kg / ha of commercially available solid humic acid powder; (3) The liquid fertilizer prepared in Example 1 was diluted 1500 times to prepare a diluted solution, which is equivalent to 25 kg / ha of humic acid + bacterial agent; (4) The liquid fertilizer prepared in Example 1 was diluted 2000 times to prepare a diluted solution; Replication: Three replicates for each treatment, with randomized block arrangement.

[0039] The above four treatment methods were applied to the topsoil of a severely saline-alkali farmland (EC≈5.2dS / m, pH≈8.3); soil EC was measured at 0, 15, 30 and 60 days after fertilization, and the test results are shown in Table 1 below.

[0040] Table 1 deal with 0dEC (dS / m) 15dEC(dS / m) 30dEC(dS / m) 60dEC(dS / m) Comparison 5.20±0.05 5.18±0.07 5.15±0.06 5.12±0.04 Humic acid powder 5.20±0.05 4.90±0.06 4.72±0.05 4.55±0.08 1,500 times 5.20±0.05 4.68±0.04 4.30±0.05 4.02±0.06 2,000 times 5.20±0.05 4.75±0.05 4.35±0.07 4.15±0.05 As can be clearly seen from Table 1 above, after applying the liquid fertilizer of the present invention, the soil EC decreased significantly within 15 days (p<0.05), and the 1,500-fold treatment group had lower EC than the humic acid powder group. At 60 days, the EC decreased by more than 1.18 dS / m, indicating that the formula of the present invention has better effects on salt leaching and ion exchange.

[0041] Example 3

[0042] This embodiment is based on the above embodiment 1, and the similarities with the above embodiment will not be repeated.

[0043] This embodiment relates to the impact on crop growth indicators.

[0044] In this embodiment, three processing methods are set, including: (1) Control group: water treatment; (2) 500 kg / ha of commercially available solid humic acid powder; (3) The liquid fertilizer prepared in Example 1 was diluted 1500 times to prepare a diluted solution; Apply the fertilizer to the roots once a week for a total of 3 times.

[0045] Plastic pots were filled with saline-alkali soil and wheat (variety "Jingmai 23") was sown, with 10 plants per pot. The above four treatments were applied to the pots. Plant height, chlorophyll content (SPAD value), and root activity (TTC reduction method) were measured 30 days after fertilization. The test results are shown in Table 2 below.

[0046] Table 2 deal with Average plant height (cm) SPAD value Root activity (µg TTC / g·h) Average plant height (cm) Comparison 18.5±0.8 25.2±1.1 120.4±5.3 18.5±0.8 Humic acid powder 21.3±0.7 30.5±1.0 145.8±4.8 21.3±0.7 1500 times 24.7±0.6 36.2±1.2 182.6±6.1 24.7±0.6 As can be clearly seen from Table 2 above, the liquid fertilizer treatment group of this invention increased plant height by 33.5%, SPAD value by 43.6%, and root activity by 51.6%, which is significantly better than humic acid powder and the control group, indicating that it has a significant effect on crop salt stress resistance and growth promotion.

[0047] Example 4 This embodiment is based on the above embodiment 1, and the similarities with the above embodiment will not be repeated.

[0048] This embodiment relates to the impact on a saline-alkali improvement demonstration field (0.1 ha in area).

[0049] In this embodiment, three processing methods are set, including: Area A: Control group: Conventional compound fertilizer was applied, consisting of 107g potassium nitrate, 102g monoammonium phosphate, 167g urea, and 1.2L water. Section B: Commercially available solid humic acid powder + conventional bacterial agent; Area C: The liquid fertilizer prepared in Example 1 was diluted 1500 times to prepare a diluted solution, and the amount of conventional NPK compound fertilizer was reduced by 20%. Water and fertilizer management should be consistent with sowing density.

[0050] The yield per unit area, thousand-grain weight, and grain protein content of wheat were determined, and the test results are shown in Table 3 below.

[0051] Table 3 deal with Yield per unit area (kg / ha) 1000-grain weight (g) Protein content (%) Area A 4800±120 38.2±0.5 11.8±0.3 Area B 5150±110 39.5±0.4 12.5±0.2 Area C 5600±100 41.0±0.6 13.2±0.3 As can be clearly seen from Table 3 above, the liquid fertilizer group (C area) of this invention, with a 20% reduction in NPK dosage, showed a 16.7% increase in yield per unit area, a 7.4% increase in thousand-grain weight, and an 11.9% increase in protein content compared to the control, demonstrating excellent yield and quality improvement effects and nutrient utilization efficiency.

[0052] The results of the three experiments in Examples 2-4 above demonstrate that the liquid water-soluble fertilizer of the present invention has significant advantages in improving saline-alkali soil, promoting crop growth, and increasing yield and quality, further verifying the practicality and economic value of the invention. Combined with the experimental data, this provides a strong scientific basis for subsequent industrial applications.

[0053] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fulvic acid liquid water-soluble fertilizer for saline-alkali soil, characterized in that, The humic acid mother liquor 200-500 parts by weight, Bacillus velezensis concentrated liquid 100-300 parts, organic chelated trace element solution 30-60 parts, solubilizing and slow-release aid 10-30 parts, anti-caking agent 1-8 parts, and stabilizer 1-5 parts are measured by weight, and purified water is added to a total amount of 1000 parts; wherein the Bacillus velezensis has a preservation number of CGMCC No: 23398.

2. The fulvic acid liquid water-soluble fertilizer for saline-alkali soil according to claim 1, characterized in that, The source of the humic acid mother liquor includes sodium humate, calcium humate, ammonium humate, or natural humic acid crude extract, and the humic acid content in the sodium humate mother liquor is greater than or equal to 25 g / L.

3. The fulvic acid liquid water-soluble fertilizer for saline-alkali soil according to claim 1, characterized in that, The live bacteria number of the B. velezensis fermentation concentrate is ≥5×10 8 CFU / mL.

4. The fulvic acid liquid water-soluble fertilizer for saline-alkali soil according to claim 1, characterized in that, The trace elements in the organic chelated trace element solution include Fe, Zn, and Mn, the content of Fe, Zn, and Mn is 2-5 g / L, and the total amount of trace elements is greater than or equal to 3 g / L.

5. The fulvic acid liquid water-soluble fertilizer for saline-alkali soil according to claim 1, characterized in that, The solubilizing and slow-release aid includes one or a combination of polyethylene glycol, propylene glycol, glycerol, and xylitol.

6. The fulvic acid liquid water-soluble fertilizer for saline-alkali soil according to claim 1, characterized in that, A pH adjuster is further included to adjust the pH to 6.5-7.

5.

7. The fulvic acid liquid water-soluble fertilizer for saline-alkali soil according to claim 6, characterized in that, The pH adjuster includes a combination of citric acid and sodium bicarbonate.

8. The fulvic acid liquid water-soluble fertilizer for saline-alkali soil according to claim 1, characterized in that, The stabilizer includes one or a combination of propylene glycol and potassium sorbate.

9. The fulvic acid liquid water-soluble fertilizer for saline-alkali soil according to claim 1, characterized in that, The anti-caking agent includes a polymeric silicate.

10. A preparation method of fulvic acid liquid water-soluble fertilizer for saline-alkali soil, characterized in that, A method for preparing a humic acid liquid water-soluble fertilizer for saline-alkali soil according to any one of claims 1-9 includes the following steps: (1) Humic acid mother liquor preparation: slowly stirring and dissolving humic acid powder in purified water at 60°C, and then filtering out impurities; (2) Bacterial liquid concentration: Bacillus velezensis is cultured using a continuous fermentation tank, and after harvesting, the bacterial liquid is concentrated to the target number of viable bacteria using a microfiltration membrane; (3) Mixing and homogenization: sequentially adding the humic acid mother liquor, organic chelated element solution, and solubilizing aid, and stirring; (4) Inoculation and stabilization: slowly adding the Bacillus velezensis concentrated liquid at 30°C, and stirring with low shear; (5) Final adjustment and packaging: adding the pH adjuster, anti-caking agent, and preservative, mixing uniformly, and then dispensing into plastic barrels or soft packaging bags.