Biomass polyhydroxycarboxyl biostimulant and cation synergistic plant activity regulation composition and preparation method thereof
By extracting biomass polyhydroxycarboxylic biostimulators from organic matter and synergistically reacting with cations, stable complexes are prepared, which solves the problems of low chelation capacity and poor biodegradability of traditional carboxylic acid additives, and improves plant nutrient absorption and stress resistance, especially in saline-alkali land and heavy metal-contaminated soils.
Patent Information
- Application Number
- CN202510522841.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-24
- Publication Date
- 2025-07-25
AI Technical Summary
Traditional carboxylic acid additives have low chelation capacity in soil, are prone to microorganisms to decompose, and have poor biodegradability. They are prone to nutrient imbalances when cationic competition adsorption, resulting in soil crunching and nutrient imbalances.
Biomass polyhydroxycarboxylic biostimulators are extracted from moderately corroded organic matter, and a mixture is formed with specific cations. Stable complexes are prepared through ultrasonic microwave synergistic extraction, gradient acid precipitation and spray drying, etc., for plant activity regulation.
Promote plant nutrient absorption, enhance stress resistance, improve plant health, vitality and yield, especially improve crop benefits under saline-alkali land improvement, heavy metal pollution repair and drought stress conditions.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical fields of agricultural functional materials and green chemistry, and particularly relates to a plant activity regulation composition with synergistic effect of biomass polyhydroxycarboxylic acid biostimulant and cation and a preparation method thereof. Background Art
[0002] The statements in this part only provide background technical information related to the present invention, and do not necessarily constitute prior art.
[0003] Carboxylic acids are a class of organic compounds characterized by the presence of a carboxyl functional group (-COOH), which consists of a carbonyl group (C=O) and a hydroxyl group (-OH) connected to the same carbon atom. Carboxylic acids are ubiquitous in nature and play important roles in various biological processes, industrial applications, and daily products.
[0004] Generally, traditional carboxylic acid additives have limitations. Single carboxylic acids (such as citric acid and oxalic acid) have low chelating capacity (≤1.2 mmol / g) and are easily decomposed by soil microorganisms quickly; synthetic polycarboxylic acids (such as polyacrylic acid) have poor biodegradability (degradation rate < 40% in 180 days), and long-term use leads to soil compaction; there are also problems with carboxylic acids in competitive adsorption of cations. Conventional chelating agents (such as EDTA) are prone to cause nutrient imbalance (such as Fe 2+ and Ca 2+ antagonism) in a multi-cation system. Summary of the Invention
[0005] The purpose of the present invention is to overcome the above deficiencies of the prior art and provide a plant activity regulation composition with synergistic effect of biomass polyhydroxycarboxylic acid biostimulant and cation and a preparation method thereof. The biomass polyhydroxycarboxylic acid biostimulant is a complex mixture extracted from moderately decomposed organic matter, mainly containing lignin, tannins, condensed aromatic compounds, fulvic acid, etc. It has a specific carbon distribution and functional group composition, and can promote the absorption and utilization of nutrients by plants and enhance the stress resistance of plants. Combining the biomass polyhydroxycarboxylic acid biostimulant with cations to form a mixture can be applied to various crops, including cereals, vegetables, fruits, and ornamental plants, etc., to improve the health, vitality, yield, and stress resistance of plants.
[0006] The present invention is achieved by the following technical solutions: The first aspect of the present invention is to provide a preparation method of a biomass polyhydroxycarboxylic acid biostimulant.
[0007] A preparation method of a biomass polyhydroxycarboxylic acid biostimulant includes the following steps: (1) Select moderately decomposed organic matter as the raw material; (2) Adopt ultrasonic-microwave synergistic extraction; (3) Solid-liquid separate the extracted solution to remove impurities; (4) After liquid purification and concentration, a biomass polyhydroxycarboxylic acid biostimulant (liquid) is obtained; (5) Spray drying to obtain a biomass polyhydroxycarboxylic acid biostimulant (powder).
[0008] The biomass polyhydroxycarboxylic acid biostimulant is a complex mixture extracted from moderately decomposed organic matter, mainly containing lignin, tannins and condensed aromatic compounds, fulvic acid, etc. It has a specific carbon distribution and functional group composition, which can promote the absorption and utilization of nutrients by plants and enhance the stress resistance of plants.
[0009] Further, the moderately decomposed organic matter in step (1) is decomposed straw, peat and other organic matters.
[0010] Even further, the requirements for organic matter are: the humification index (HI = H / C) is 0.6 - 1.2; the ash content ≤ 5%, and the C / N ratio is 25 - 40.
[0011] Further, in step (2), the solvent system used in the extraction process is an ethanol-water-potassium hydroxide mixture (volume ratio 6 - 4:6 - 3:3 - 1, pH 9.0 - 11.0), and ultrasonic-microwave assisted extraction is carried out at 50 - 60 °C for 1 - 4 hours.
[0012] Further, in step (3), the extracted solution is solid-liquid separated to remove impurities.
[0013] Even further, solid-liquid separation is carried out by high-speed centrifugation in a centrifuge to remove impurities, and the operating parameters of the centrifuge are 5000 - 20000 RPM / 0.5 - 2 hours / room temperature.
[0014] Further, in step (4), the purification process is gradient acid precipitation and concentration.
[0015] Even further, gradient acid precipitation: adjust the pH to 5.0, 3.0, 1.5 in sequence with 1M H2SO4 to fractionally precipitate different polyhydroxycarboxyl matrices. After gradient precipitation, centrifuge for solid-liquid separation, preferably, the operating parameters of the centrifuge are 5000 - 20000 RPM / 0.5 - 2 hours / room temperature.
[0016] Even further, multi-effect evaporation or reverse osmosis concentration: concentrate using a multi-effect evaporator or reverse osmosis membrane to obtain a concentrated solution of biomass polyhydroxycarboxylic acid biostimulant (liquid).
[0017] Further, in step (5), the specific conditions for spray drying are: inlet temperature 160 - 180 °C, outlet temperature 60 - 80 °C, to obtain a biomass polyhydroxycarboxylic acid biostimulant (powder).
[0018] The second aspect of the present invention is to provide a plant activity regulating composition.
[0019] The biomass polyhydroxycarboxylic acid biostimulant (liquid, powder) is complexed with metal cations, where the metal cations are one or more of magnesium ions, iron ions, zinc ions, calcium ions, manganese ions, copper ions, molybdenum ions, potassium ions.
[0020] The weight of the biomass polyhydroxycarboxylic acid biostimulant (liquid, powder) is chelated with one or more of the metal cations according to a weight ratio of 1:0.1 - 0.6 to form a stable complex; 0.01% - 0.5% of a dispersant is added to prevent cation precipitation, and a stable composition is obtained. The dispersant is one or more of organosilicon dispersants (polyether-modified silicone oil, amino-modified silicone oil, trisiloxane derivatives, bio-based organosilicon), bio-based dispersants (xanthan gum, poly(malic acid), poly(aspartic acid)), etc.
[0021] The third aspect of the present invention is to provide the application of the plant activity regulating composition in agricultural regulation.
[0022] An effective amount of the biomass polyhydroxycarboxylic acid biostimulant in the composition, and it can have a positive impact on at least one biological process of plants; in particular, a method of contacting a plant or its growth location with a mixture containing the biomass polyhydroxycarboxylic acid biostimulant and additional cations. These methods and compositions can be applied to various crops, including cereals, vegetables, fruits, and ornamental plants, etc., to improve the health, vigor, yield, and stress resistance of plants.
[0023] The above applications mainly include promoting plant root growth, improving saline-alkali land, repairing heavy metal pollution, and improving the quality and efficiency of crops under drought stress conditions.
[0024] Beneficial effects The present invention extracts a biomass polyhydroxycarboxylic acid biostimulant (Biomass-derived Polyhydroxy Carboxylic Acid Biostimulant - BPCA - BS) from moderately decomposed organic matter and synergistically acts with specific cations to regulate plant biological activities (such as nutrient absorption, stress resistance, photosynthetic efficiency), and a composition and preparation method thereof. This technology is particularly suitable for promoting plant root growth, improving saline-alkali land, repairing heavy metal pollution, and improving the quality and efficiency of crops under drought stress conditions. Specific embodiments
[0025] The technical solutions of the present invention will be further explained and illustrated below through specific examples. The experimental supplies used in the present invention are all commercially available.
[0026] Raw material selection: Moderately humified organic matter (such as decomposed straw, peat, etc.) is selected.
[0027] Extraction process: Use appropriate solvents (such as water, ethanol, methanol, potassium hydroxide solution, etc.) for ultrasonic-microwave assisted extraction.
[0028] Solid-liquid separation: Centrifuge for solid-liquid separation to remove impurities.
[0029] Purification and concentration: Further purify the extract by methods such as gradient acid precipitation and reverse osmosis membrane concentration.
[0030] Drying and storage: Dry the purified biomass polyhydroxycarboxylic acid biostimulant (liquid) to obtain a solid product (powder).
[0031] Application forms of biomass polyhydroxycarboxylic acid biostimulant and its mixtures: The biomass polyhydroxycarboxylic acid biostimulant can be provided in the forms of liquid, powder, granules, etc., and is suitable for seed treatment, foliar spraying or soil application. It can also be mixed with other fertilizers or pesticides to improve agricultural efficiency.
[0032] (1) Select moderately decomposed organic matter as the raw material. Requirements for organic matter: Humification index (HI = H / C) is 0.6 - 1.2; ash content ≤ 5%, C / N ratio 25 - 40.
[0033] (2) Use ultrasonic-microwave assistance to extract biomass polyhydroxycarboxylic acid biostimulant from humification intermediates. Its molecules have both high-density functional groups and aromatic skeletons, enhancing chelation stability; the oxygen-carbon ratio of dissolved organic matter (DOM) is greater than 0.5; the mass distribution is approximately 55 - 60% lignin compounds, 27 - 35% tannin compounds, and approximately 8 - 15% condensed hydrocarbons.
[0034] (3) Use a centrifuge for solid-liquid separation to remove impurities.
[0035] (4) Use a combined technology of gradient acid precipitation - membrane separation to precisely control the molecular weight and hydroxycarboxyl distribution of biomass polyhydroxycarboxylic acid biostimulant to obtain biomass polyhydroxycarboxylic acid biostimulant BPCA-BS (liquid); (5) Spray drying to obtain biomass polyhydroxycarboxylic acid biostimulant BPCA-BS (powder).
[0036] (6) Application methods Soil drip irrigation: The biomass polyhydroxycarboxylic acid biostimulant BPCA-BS and metal cation composition are diluted 500 - 1500 times and applied in portions during the critical growth stages of crops (jointing stage, filling stage). The dosage of biomass polyhydroxycarboxylic acid biostimulant (powder) is 10 - 500 g / mu.
[0037] Foliar spraying: A composition of biomass polyhydroxycarboxylic acid biostimulant BPCA-BS and metal cations, diluted 1000 - 5000 times for spraying, with the dosage of biomass polyhydroxycarboxylic acid biostimulant BPCA-BS (powder) being 10 - 200 g / mu.
[0038] Example 1 A preparation method of biomass polyhydroxycarboxylic acid biostimulant BPCA-BS includes the following steps: (1) Select moderately decomposed straw as the raw material. Requirements for organic matter: Humification index (HI = H / C) is 1.0; ash content is 5%, and C / N ratio is 25.
[0039] (2) Adopt ultrasonic-microwave synergistic extraction. The solvent system used in the extraction process is an ethanol-water-potassium hydroxide mixture (volume ratio 5:3:1, pH 10.0), and carry out ultrasonic (100 kHz) - microwave (2.45 GHz) synergistic extraction at 60°C for 2 hours.
[0040] (3) Centrifuge the extracted solution to separate the solid and liquid. The operating parameters of the centrifuge are 10000 RPM / 1 hour / room temperature.
[0041] (4) After separation, the liquid is first subjected to gradient acid precipitation. Adjust the pH to 5.0, 3.0, and 1.5 successively with 1M H2SO4 to precipitate different polyhydroxycarboxyl matrices step by step; after gradient precipitation, centrifuge to separate the solid and liquid. The operating parameters of the centrifuge are 15000 RPM / 2 hours / room temperature; then concentrate using a Dow SW30HRLE-400 reverse osmosis membrane to obtain a concentrated solution of biomass polyhydroxycarboxylic acid biostimulant (liquid).
[0042] (5) The inlet temperature of spray drying is 180°C, and the outlet temperature is 80°C to obtain biomass polyhydroxycarboxylic acid biostimulant (powder).
[0043] Table 1 shows the characteristic parameters of biomass polyhydroxycarboxylic acid biostimulant BPCA-BS (powder) in Example 1 Example 2 A preparation method of biomass polyhydroxycarboxylic acid biostimulant includes the following steps: (1) Select moderately decomposed peat as the raw material. Requirements for organic matter: Humification index (HI = H / C) is 0.8, ash content is 4%, and C / N ratio is 35.
[0044] (2) Adopt ultrasonic-microwave synergistic extraction. The solvent system used in the extraction process is an ethanol-water-potassium hydroxide mixture (volume ratio 5:2:1, pH 9.0), and carry out ultrasonic (90 kHz) - microwave (2.45 GHz) synergistic extraction at 60°C for 3 hours.
[0045] (3) Centrifuge the extracted solution to separate solids from liquids. The operating parameters of the centrifuge are 10,000 RPM / 1.5 hours / room temperature.
[0046] (4) After separation, first perform gradient acid precipitation. Adjust the pH to 5.0, 3.0, and 1.5 successively with 1M H2SO4 to precipitate different polyhydroxycarboxylate matrices step by step. After gradient precipitation, centrifuge to separate solids from liquids. The operating parameters of the centrifuge are 15,000 RPM / 2 hours / room temperature. Then, concentrate using a Dow SW30HRLE-400 reverse osmosis membrane to obtain a concentrated solution of biomass polyhydroxycarboxylate biostimulant (liquid).
[0047] (5) The inlet temperature for spray drying is 180 °C and the outlet temperature is 80 °C to obtain biomass polyhydroxycarboxylate biostimulant (powder).
[0048] Table 2 shows the characteristic parameters of biomass polyhydroxycarboxylate biostimulant BPCA-BS (powder) in Example 2 Comparative Example 1 A method for preparing a biostimulant, comprising the following steps: (1) Select moderately decomposed and composted straw as the raw material. Requirements for organic matter: humification index (HI = H / C) is 1.2; ash content is 4%, and C / N ratio is 27.
[0049] (2) Use ultrasonic-microwave synergistic extraction. The solvent system used during the extraction process is an ethanol-water mixture (volume ratio 4:3), and perform ultrasonic (90 kHz) - microwave (2.45 GHz) synergistic extraction at 60 °C for 2 hours.
[0050] (3) Centrifuge the extracted solution to separate solids from liquids. The operating parameters of the centrifuge are 10,000 RPM / 1 hour / room temperature.
[0051] (4) After separation, perform gradient acid precipitation. Adjust the pH to 5.0 and 3.0 successively with 1M H2SO4 to precipitate different hydroxycarboxylate matrices step by step. After gradient precipitation, centrifuge to separate solids from liquids. The operating parameters of the centrifuge are 10,000 RPM / 1 hour / room temperature. Then, concentrate using a Dow SW30HRLE-400 reverse osmosis membrane to obtain the product of Comparative Example 1 (liquid).
[0052] (5) The inlet temperature for spray drying is 180 °C and the outlet temperature is 80 °C to obtain the product of Comparative Example 1 (powder).
[0053] Comparative Example 2 A method for preparing a biostimulant, comprising the following steps: (1) Select moderately decomposed peat as the raw material. Requirements for organic matter: humification index (HI = H / C) is 0.9; ash content is 3.5%, and C / N ratio is 36.
[0054] (2) Use ultrasonic extraction. The solvent system used during the extraction process is an ethanol - water - potassium hydroxide mixture (volume ratio 3:2:1, pH 9.0). Ultrasonic extraction is carried out at 60 °C (100 kHz) for 3 hours.
[0055] (3) Centrifuge the extracted solution to separate the solid and liquid. The operating parameters of the centrifuge are 10000 RPM / 1 hour / normal temperature.
[0056] (4) After separation, perform acid precipitation. Use 1M H2SO4 to adjust the pH to 5.0 and 3.0 to precipitate different hydroxycarboxyl matrices step by step. After gradient precipitation, centrifuge to separate the solid and liquid. The operating parameters of the centrifuge are 15000 RPM / 1.5 hours / normal temperature. Then, concentrate using Dow SW30HRLE - 400 reverse osmosis membrane to obtain the biostimulant concentrate (liquid) of Comparative Example 2.
[0057] (5) The inlet temperature of spray drying is 180 °C, and the outlet temperature is 80 °C to obtain the biostimulant (powder) of Comparative Example 2.
[0058] Application Example 1 Rice experiment in saline - alkali land Soil conditions: Select saline - alkali land soil in a certain place in Inner Mongolia. Measure the soil pH of 9.1, EC of 7.5 mS / cm, ammonium nitrogen of 25.5 mg / kg, available phosphorus of 12.2 mg / kg, and available potassium of 21.6 mg / kg. Divide the soil into 4 equal parts and treat them separately.
[0059] Among them, the treatment group: Dissolve the BPCA - BS (powder) prepared in Example 1 in deionized water, control the concentration at 5% (w / v), and heat to 45 °C to accelerate dissolution. Add Mg 2+ / Fe 2+ (Mg 2+ from magnesium sulfate, Fe 2+ from ferrous sulfate), stir until completely dissolved, stirring speed: 300 rpm. Add 0.2% polyaspartic acid (PASP), control the continuous stirring reaction at 45 °C for 2 hours, then filter to remove unreacted impurities to obtain a chelated solution. After diluting 500 times, drip - irrigate 3 times, and the dosage of BPCA - BS (powder) is 150 g / mu.
[0060] Control group: Treat with the same amount of citric acid and drip - irrigate 3 times.
[0061] Comparative example group: The product (powder) prepared in Comparative Example 1 was dissolved in deionized water, and the concentration was controlled at 5% (w / v), and it was heated to 45 °C to accelerate dissolution. Mg was added according to the weight ratio of the product powder prepared in Comparative Example 1 to metal cations of 1:(0.2 / 0.3) 2+ / Fe 2+ (Mg 2+ from magnesium sulfate, Fe 2+ from ferrous sulfate), and stirred until completely dissolved, stirring speed: 300 rpm. 0.2% of polyaspartic acid (PASP) was added, and after continuously stirring and reacting at 45 °C for 2 hours, the unreacted impurities were removed by filtration to obtain a chelating solution. After diluting 500 times, it was drip-irrigated 3 times, and the dosage of the product (powder) prepared in Comparative Example 1 was 150 g / mu.
[0062] The product powder prepared in Comparative Example 2 was dissolved in deionized water, and the concentration was controlled at 5% (w / v), and it was heated to 45 °C to accelerate dissolution. Mg was added according to the weight ratio of the product powder prepared in Comparative Example 2 to metal cations of 1:(0.2 / 0.3) 2+ / Fe 2+ (Mg 2+ from magnesium sulfate, Fe 2+ from ferrous sulfate), and stirred until completely dissolved, stirring speed: 300 rpm. 0.2% of polyaspartic acid (PASP) was added, and after continuously stirring and reacting at 45 °C for 2 hours, the unreacted impurities were removed by filtration to obtain a chelating solution. After diluting 500 times, it was drip-irrigated 3 times, and the dosage of the product (powder) prepared in Comparative Example 2 was 150 g / mu.
[0063] Rice planting tests were carried out. The products of Example 1 and Comparative Examples 1 and 2 were subjected to performance tests, and the performance measurement results were as follows: Table 3 Soil improvement effect It can be seen from the test that in Example 1, the soil EC dropped to 4.5 mS / cm, the rice root activity (TTC reduction amount) increased by 50% compared with the control group; the 1000-grain weight of rice increased by 18% compared with the control group, and the yield increased by 19% compared with the control group.
[0064] Application Example 2 Heavy metal pollution remediation test Contaminated soil was selected for the test. The available Cd in the soil was 2.0 mg / kg and Pb was 150 mg / kg. The soil was divided into 2 identical pieces and treated separately.
[0065] Treatment group: 200 kg / acre of biochar + BPCA-BS (powder) prepared in Example 1 of the treatment was dissolved in deionized water, and the concentration was controlled at 5% (w / v), and heated to 45 °C to accelerate dissolution. Zn was added according to the weight ratio of BPCA-BS (powder) to metal cations of 1:(0.2:0.2). 2+ , Ca 2+ (Zn 2+ from zinc sulfate, Ca 2+ from calcium nitrate), stirred until completely dissolved, stirring speed: 300 rpm. 0.2% of polyaspartic acid (PASP) was added, and after continuously stirring and reacting at 45 °C for 2 hours, the unreacted impurities were removed by filtration to obtain a chelated solution. After diluting 500 times, it was drip-irrigated 3 times, and the dosage of BPCA-BS (powder) was 500 g / acre.
[0066] Control group: Treated with the same mass of biochar.
[0067] Effect: After being treated with BPCA-BS prepared in Example 1 of the present invention, the available Cd in the soil decreased by 38%, and Pb decreased by 52%.
[0068] Application Example 3 Drought stress regulation test The same drought soil was selected for the test. The soil was divided into 2 identical plots, and the same corn was planted, and the two plots of land were treated separately.
[0069] Treatment group: BPCA-BS-Mg 2+ / Fe 2+ Foliar spray; Dissolve the BPCA-BS (powder) prepared in Example 1 in deionized water, and control the concentration at 5% (w / v), and heat to 45 °C to accelerate dissolution. Add Zn according to the weight ratio of BPCA-BS powder to metal cations of 1:(0.3 / 0.3). 2+ / Mg 2+ (Zn 2+ from zinc sulfate, Mg 2+ from magnesium sulfate), stirred until completely dissolved, stirring speed: 300 rpm. 0.2% of polyaspartic acid (PASP) was added, and after continuously stirring and reacting at 45 °C for 2 hours, the unreacted impurities were removed by filtration to obtain a chelated solution. After diluting 1000 times, it was sprayed 5 times, and the dosage of BPCA-BS (powder) was 100 g / acre.
[0070] Control group: Sprayed and treated with the same mass of zinc sulfate and magnesium sulfate.
[0071] Effect: After being treated with BPCA-BS prepared in Example 1 of the present invention, the drought reduction rate of corn decreased from 50% to 28%.
[0072] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A preparation method of a biomass polyhydroxycarboxylic acid biostimulant, characterized in that, It includes the following steps: (1) Select moderately decomposed organic matter as the raw material; (2) Adopt ultrasonic-microwave synergistic extraction; (3) Separate the solid and liquid of the extracted solution to remove impurities; (4) Obtain bio-stimulator of biomass polyhydroxycarboxylic acid (liquid) after purification and concentration treatment; (5) Obtain bio-stimulator of biomass polyhydroxycarboxylic acid (powder) by spray drying or multi-effect evaporation.
2. The preparation method of a biomass polyhydroxycarboxylic acid biostimulant according to claim 1, characterized in that, The moderately decomposed organic matter in step (1) is biomass such as decomposed straw or peat; preferably, the requirements for the organic matter are: the humification index is 0.6 - 1.2; the ash content ≤ 5%, and the C / N ratio is 25 - 40.
3. The preparation method of a biomass polyhydroxycarboxylic acid biostimulator according to claim 1, characterized in that, In step (2), the solvent system used in the extraction process is an ethanol-water-potassium hydroxide mixed solution with a volume ratio of 6 - 4:6 - 3:3 - 1, the pH of the mixed solution is 9.0 - 11.0, and ultrasonic-microwave synergistic extraction is carried out at 60°C for 1 - 4 hours.
4. The preparation method of a biomass polyhydroxycarboxylic acid biostimulant according to claim 1, characterized in that, In step (3), separate the solid and liquid of the extracted solution to remove impurities. Solid-liquid separation is carried out by high-speed centrifugation of a centrifuge to remove impurities. Preferably, the operating parameters of the centrifuge are 5000 - 15000 RPM / 0.5 - 2 hours / normal temperature.
5. The preparation method of a biomass polyhydroxycarboxylic acid biostimulator according to claim 1, characterized in that, In step (4), the purification process is gradient acid precipitation, multi-effect evaporation or reverse osmosis membrane concentration; preferably, gradient acid precipitation: adjust the pH to 5.0, 3.0, 1.5 in sequence with 1M H2SO4 to precipitate different polyhydroxycarboxyl bodies step by step; after gradient precipitation, carry out centrifugation by a centrifuge for solid-liquid separation. Preferably, the operating parameters of the centrifuge are 5000 - 20000 RPM / 0.5 - 2 hours / normal temperature, and the liquid part is concentrated by multi-effect evaporation or reverse osmosis membrane to obtain a concentrated solution of bio-stimulator of biomass polyhydroxycarboxylic acid (liquid).
6. The preparation method of a biomass polyhydroxycarboxylic acid biostimulator according to claim 1, characterized in that, In step (5), the specific conditions for spray drying are: the inlet temperature is 160 - 180°C, and the outlet temperature is 60 - 80°C to obtain bio-stimulator of biomass polyhydroxycarboxylic acid (powder).
7. A plant activity regulating composition, in which the bio-stimulator of biomass polyhydroxycarboxylic acid (liquid, powder) prepared by the preparation method according to any one of claims 1 - 6 is complexed with an effective amount of metal cations, and the metal cations are one or more of magnesium ions, iron ions, zinc ions, calcium ions, manganese ions, copper ions, molybdenum ions, potassium ions.
8. According to a plant activity regulating composition as claimed in claim 7, the weight of the bio-stimulator of biomass polyhydroxycarboxylic acid (liquid, powder) and one or more of the metal cations are chelated in a weight ratio of 1:0.1 - 0.6 to form a stable complex; add 0.01% - 0.5% of a dispersant to prevent cation precipitation to obtain a stable composition; wherein the dispersant is one or more of organosilicon dispersants (polyether-modified silicone oil, amino-modified silicone oil, trisiloxane derivatives, bio-based organosilicon), bio-based dispersants (xanthan gum, poly(malic acid), poly(aspartic acid)), etc.
9. An application of the bio-stimulator of biomass polyhydroxycarboxylic acid (liquid, powder) prepared by the preparation method according to any one of claims 1 - 6 or the composition according to any one of claims 7 - 8 in agricultural regulation.
10. The application according to claim 9, characterized in that, The agricultural regulation described above is for promoting the growth of plant roots, improving saline-alkali land, repairing heavy metal pollution, or improving the quality and efficiency of crops under the regulation conditions of drought stress.