Ginkgo leaf stock solution, flavone-rich plant nutrition fertilizer, and preparation method and application of ginkgo leaf stock solution and flavone-rich plant nutrition fertilizer

Abstract

The invention relates to the technical field of fertilizers, in particular to a ginkgo leaf stock solution, a flavone-rich plant nutrition fertilizer and a preparation method and application of the ginkgo leaf stock solution and the flavone-rich plant nutrition fertilizer. The invention provides a preparation method of a ginkgo leaf stock solution, which comprises the following steps: taking pure grain white spirit as an extraction solvent, and performing stepped temperature control soaking to obtain a ginkgo leaf extracting solution; the ginkgo leaf stock solution is prepared by compounding the ginkgo leaf extracting solution with ammonium zinc sulfate, potassium alginate, humic acid and sodium dihydrogen phosphate, and the ginkgo leaf stock solution can effectively promote plant growth, improve stress resistance, increase flavone accumulation and increase yield; the ginkgo leaf stock solution and the pure grain fermentation mother solution are compounded to prepare the nutrition fertilizer, the advantages of combination of organic and inorganic components and combination of nutrition and biological stimulation are fully exerted, the content of total flavonoids in crops can be effectively increased, meanwhile, crop growth is remarkably promoted, and the crop yield is increased.

Description

Technical Field

[0001] This invention relates to the field of fertilizer technology, and in particular to a ginkgo leaf extract, a flavonoid-rich plant nutrient fertilizer, and their preparation methods and applications. Background Technology

[0002] Ginkgo leaves are rich in flavonoids and other active ingredients, possessing high nutritional and application value. Currently, ginkgo leaves are primarily used in the pharmaceutical and health product industries, with limited development and utilization in agriculture. Furthermore, existing technologies for extracting active ingredients from ginkgo leaves often employ methods such as organic solvent reflux, ultrasonic or microwave-assisted extraction, which suffer from complex processes, high energy consumption, organic solvent residues, and potential destruction of active ingredients. Simultaneously, current plant fertilizers mainly focus on providing basic nutrients such as nitrogen, phosphorus, and potassium, failing to meet the crop's demand for flavonoids and thus unable to achieve the dual goals of increasing crop flavonoid content and yield. Therefore, developing a technology that efficiently utilizes ginkgo leaf resources and can improve crop flavonoid content and yield has become a crucial need in the agricultural sector. Summary of the Invention

[0003] The purpose of this invention is to provide a ginkgo leaf extract and a flavonoid-rich plant fertilizer that can effectively increase the total flavonoid content in crops, significantly promote crop growth, and increase crop yield.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a method for preparing Ginkgo biloba extract, comprising the following steps:

[0006] (1) Mix dried ginkgo leaves with pure grain liquor and soak at 20-30℃ for 0.5-1.5h, then heat to 50-60℃ and soak for 2-3h. Filter and take the filtrate to obtain ginkgo leaf extract.

[0007] (2) After cooling the Ginkgo leaf extract to 25-30℃, mix it with zinc ammonium sulfate, potassium alginate, humic acid and sodium dihydrogen phosphate, stir and let it stand to obtain the original Ginkgo leaf solution.

[0008] Preferably, in step (1), the mass-to-volume ratio of the dried ginkgo leaves and the pure grain liquor is 1:15 to 25.

[0009] Preferably, in step (2), the mass ratio of ginkgo leaf extract to zinc ammonium sulfate is 1:0.04 to 0.06.

[0010] The mass ratio of potassium alginate to ginkgo leaf extract is 1:0.05-0.07;

[0011] The mass ratio of ginkgo leaf extract to humic acid was 1:0.03–0.05.

[0012] The mass ratio of ginkgo leaf extract to sodium dihydrogen phosphate is 1:0.015 to 0.025.

[0013] Preferably, in step (2), the stirring speed is 250-350 rpm and the stirring time is 15-25 min.

[0014] Preferably, in step (2), the settling time is 2 to 3 hours.

[0015] The present invention also provides a ginkgo leaf extract prepared by the aforementioned preparation method.

[0016] The present invention also provides the application of the ginkgo leaf extract prepared by the above preparation method, or the application of the ginkgo leaf extract in the preparation of fertilizers that increase the total flavonoid content of crops and increase crop yield.

[0017] This invention also provides a flavonoid-rich plant nutrient fertilizer, comprising the following components in parts by weight: 2-4 parts ginkgo leaf extract, 1-3 parts pure grain yeast extract;

[0018] The ginkgo leaf extract is either the ginkgo leaf extract prepared by the aforementioned preparation method or the ginkgo leaf extract described above.

[0019] Preferably, the pure grain yeast liquid is prepared by solid-state fermentation with grain as the main component.

[0020] The grain is one of rice, sorghum, highland barley, or barley.

[0021] As a preferred method, the following steps are included: mixing ginkgo leaf extract and pure grain yeast extract to obtain flavonoid-rich plant fertilizer.

[0022] The beneficial effects of this invention are:

[0023] 1. This invention uses pure grain liquor as the extraction solvent, which is safe and non-toxic. By using stepped temperature control (low temperature first, then medium temperature) for soaking, it can effectively extract active substances such as flavonoids from ginkgo leaves, while reducing the damage of heat-sensitive components to high temperatures, thus improving extraction efficiency and the integrity of active ingredients.

[0024] 2. Based on the extract, this invention scientifically combines zinc ammonium sulfate (providing trace element zinc), potassium alginate (a natural biostimulant), humic acid (improving soil and promoting absorption), and sodium dihydrogen phosphate (providing phosphorus source and regulating the system). These components work synergistically with the active ingredients of ginkgo leaves to promote plant growth, enhance stress resistance, increase flavonoid accumulation, and improve yield.

[0025] 3. This invention combines the prepared ginkgo leaf extract with pure grain yeast liquid to make a nutrient fertilizer, which fully utilizes the advantages of combining organic and inorganic components and combining nutrition with biostimulation. It can effectively increase the total flavonoid content in crops, while significantly promoting crop growth and increasing crop yield.

[0026] 4. The entire process of this invention requires no complex equipment, operates under mild conditions, consumes little energy, is suitable for large-scale production, and has good application prospects. Detailed Implementation

[0027] This invention provides a method for preparing Ginkgo biloba extract, comprising the following steps:

[0028] (1) Mix dried ginkgo leaves with pure grain liquor and soak at 20-30℃ for 0.5-1.5h, then heat to 50-60℃ and soak for 2-3h. Filter and take the filtrate to obtain ginkgo leaf extract.

[0029] (2) After cooling the Ginkgo leaf extract to 25-30℃, mix it with zinc ammonium sulfate, potassium alginate, humic acid and sodium dihydrogen phosphate, stir and let it stand to obtain the original Ginkgo leaf solution.

[0030] In this invention, the method for preparing the dried ginkgo leaves is as follows: drying the ginkgo leaves to a moisture content of ≤6%, preferably to a moisture content of 3%;

[0031] The drying temperature is 50-60℃, preferably 53-57℃, and more preferably 55℃;

[0032] The mass-to-volume ratio of the dried ginkgo leaves and pure grain liquor is 1:15-25, preferably 1:18-22, and more preferably 1:20.

[0033] The preferred ginkgo leaves are mature leaves from dwarfed young trees that are 2 to 4 years old, taken after the White Dew solar term.

[0034] The alcohol content of the pure grain liquor is ≥50 LoV, preferably 60 LoV;

[0035] The temperature before heating is preferably 23-27°C, more preferably 25°C, and the soaking time is preferably 0.8-1.2 hours, more preferably 1 hour.

[0036] The temperature after heating is preferably 53-57℃, more preferably 55℃, and the soaking time is preferably 2.3-2.7h, more preferably 2.5h.

[0037] This invention selects pure grain liquor as the extraction solvent for ginkgo leaves. The ethanol and water in the liquor form a mixed solvent system that can efficiently dissolve fat-soluble active components such as flavonoids and terpenes in ginkgo leaves, while also dissolving some water-soluble active substances. This caters to the dissolution requirements of components with different polarities. Furthermore, pure grain liquor is safe to obtain and free of harmful impurities, avoiding adverse effects on subsequent fertilizer application and crop growth. In addition, pure grain liquor contains trace amounts of esters and organic acids produced during grain fermentation, which can help stabilize the heat-sensitive active components of ginkgo leaves during extraction, reducing the damage to the component structure caused by high temperatures or single solvents. High concentrations of pure alcohol can easily lead to… The structure of some active ingredients (such as terpenes) is denatured during pure water extraction, which easily leads to the dissolution of large amounts of ineffective impurities such as polysaccharides and pectin, increasing the difficulty of subsequent purification and affecting the purity of the active ingredients in the extract. A temperature gradient extraction method, employing a low-temperature pre-soaking at 20–30℃ and a high-temperature deep extraction at 50–60℃, allows for the preferential dissolution of free, easily soluble active ingredients under mild conditions during the low-temperature stage, while protecting heat-sensitive components from oxidative degradation. The high-temperature stage enhances the molecular mobility and permeability of the solvent, promoting the full dissolution of bound and poorly soluble active ingredients. Furthermore, this temperature range does not lead to excessive ethanol volatilization and reduces the significant destruction of heat-sensitive components. Therefore, the solvent characteristics of pure grain liquor provide a suitable basis for temperature gradient extraction, which in turn leverages the dissolution advantages of pure grain liquor for components of different polarities. The synergistic effect of both methods achieves comprehensive and efficient extraction of active ingredients from ginkgo leaves, while maximizing the preservation of component activity. This provides a high-quality raw material guarantee for the subsequent preparation of flavonoid-rich plant fertilizers, enhancing the total flavonoid content and yield of crops.

[0038] In this invention, in step (2), the temperature after cooling is preferably 27-28°C, and more preferably 27.5°C;

[0039] The mass ratio of ginkgo leaf extract to zinc ammonium sulfate is 1:0.04 to 0.06, preferably 1:0.05;

[0040] The mass ratio of potassium alginate to ginkgo leaf extract is 1:0.05 to 0.07, preferably 1:0.06;

[0041] The mass ratio of ginkgo leaf extract to humic acid is 1:0.03 to 0.05, preferably 1:0.04;

[0042] The mass ratio of ginkgo leaf extract to sodium dihydrogen phosphate is 1:0.015 to 0.025, preferably 1:0.02;

[0043] Ginkgo leaf extract is rich in flavonoids, terpenes, and other bioactive substances. Synergistically, it works with potassium alginate and humic acid to improve soil structure, promote root development, and enhance crop nutrient absorption. Humic acid chelates zinc ions in zinc ammonium sulfate and phosphorus in sodium dihydrogen phosphate, increasing the availability of zinc and phosphorus nutrients and reducing their fixation and loss in the soil. Zinc provided by zinc ammonium sulfate is a coenzyme for key enzymes in flavonoid synthesis, while phosphorus provided by sodium dihydrogen phosphate provides energy for flavonoid synthesis. Together with the flavonoids in the ginkgo leaf extract itself, these components can induce the upregulation of flavonoid synthesis-related genes in crops, promoting total flavonoid accumulation. Simultaneously, the nitrogen, phosphorus, zinc, and other nutrients and bioactive substances provided by each component complement each other, comprehensively stimulating crop physiological vitality and enhancing stress resistance, ultimately synergistically increasing the total flavonoid content and yield of crops.

[0044] In this invention, in step (2), the stirring speed is 250-350 rpm, preferably 280-320 rpm, and more preferably 300 rpm; the stirring time is 15-25 min, preferably 18-22 min, and more preferably 20 min.

[0045] In this invention, in step (2), the settling time is 2 to 3 hours, preferably 2.3 to 2.7 hours, and more preferably 2.5 hours.

[0046] The present invention also provides a ginkgo leaf extract prepared by the aforementioned preparation method.

[0047] The present invention also provides the application of the ginkgo leaf extract prepared by the above preparation method, or the application of the ginkgo leaf extract in the preparation of fertilizers that increase the total flavonoid content of crops and increase crop yield.

[0048] This invention also provides a flavonoid-rich plant fertilizer, comprising the following components in parts by weight:

[0049] 2-4 parts of Ginkgo biloba extract, preferably 3 parts;

[0050] Use 1 to 3 parts of pure grain yeast liquid, preferably 2 parts;

[0051] The ginkgo leaf extract is either the ginkgo leaf extract prepared by the aforementioned preparation method or the ginkgo leaf extract described above.

[0052] In this invention, the pure grain yeast liquid is prepared by solid-state fermentation with grain as the main component; the grain is one of rice, sorghum, highland barley or barley;

[0053] The preparation method of the pure grain yeast liquid is as follows:

[0054] Mix the grains at a mass-to-volume ratio of 1:3 and soak for 30 minutes. Remove the grains and steam them at 100℃ for 40 minutes to obtain cooked grains. When the temperature naturally drops to 35℃, mix the cooked grains with yeast at a mass ratio of 250:1 and ferment at room temperature for 8 days to obtain the fermentation product. Mix the fermentation product with water at a mass ratio of 1:3, seal and ferment for 21 days. Filter and take the filtrate as pure grain yeast liquid.

[0055] The present invention includes the following steps: mixing ginkgo leaf extract and pure grain yeast extract to obtain flavonoid-rich plant nutrient fertilizer;

[0056] The method of using the flavonoid-rich plant nutrient fertilizer is as follows: Mix the flavonoid-rich plant nutrient fertilizer and water at a volume ratio of 1:4 to 8, and then spray it on the leaves or water the roots.

[0057] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0058] Example 1: A Ginkgo Leaf Extract

[0059] (1) Pick mature ginkgo leaves after the White Dew season from 3-year-old dwarfed saplings, dry them at 60℃ to a moisture content of 5% to obtain dried ginkgo leaves, mix the dried ginkgo leaves with 60LoV (alcohol content) pure grain liquor (the mass ratio of dried ginkgo leaves to pure grain liquor is 1:20), soak them at 25℃ for 1 hour, raise the temperature to 60℃ and soak them for 3 hours, filter, take the filtrate, and obtain ginkgo leaf extract.

[0060] (2) After cooling 10 kg of Ginkgo leaf extract to 25°C, mix it with 0.5 kg of zinc ammonium sulfate, 0.6 kg of potassium alginate, 0.4 kg of humic acid and 0.2 kg of sodium dihydrogen phosphate. Stir at 300 rpm for 20 min and let stand for 3 h to obtain Ginkgo leaf stock solution.

[0061] Example 2: A Ginkgo Leaf Extract

[0062] (1) Pick mature ginkgo leaves after the White Dew season from 3-year-old dwarfed saplings, dry them at 50℃ to a moisture content of 4% to obtain dried ginkgo leaves, mix the dried ginkgo leaves with 50LoV (alcohol content) pure grain liquor (the mass ratio of dried ginkgo leaves to pure grain liquor is 1:25), soak at 30℃ for 0.8h, raise the temperature to 55℃ and soak for 2h, filter, take the filtrate to obtain ginkgo leaf extract;

[0063] (2) After cooling 10 kg of Ginkgo leaf extract to 30°C, mix it with 0.6 kg of zinc ammonium sulfate, 0.5 kg of potassium alginate, 0.5 kg of humic acid and 0.15 kg of sodium dihydrogen phosphate. Stir at 350 rpm for 15 min and let stand for 2.5 h to obtain Ginkgo leaf stock solution.

[0064] Example 3: A Ginkgo Leaf Extract

[0065] (1) Pick mature ginkgo leaves after the White Dew season from 3-year-old dwarfed saplings, dry them at 55℃ to a moisture content of 3%, and obtain dried ginkgo leaves. Mix the dried ginkgo leaves with 55LoV (alcohol content) pure grain liquor (the mass ratio of dried ginkgo leaves to pure grain liquor is 1:18), soak them at 28℃ for 0.5h, raise the temperature to 50℃ and soak them for 2.5h, filter, and take the filtrate to obtain ginkgo leaf extract.

[0066] (2) After cooling 10 kg of Ginkgo leaf extract to 28°C, mix it with 0.4 kg of zinc ammonium sulfate, 0.7 kg of potassium alginate, 0.3 kg of humic acid and 0.25 kg of sodium dihydrogen phosphate. Stir at 250 rpm for 25 min and let stand for 2 h to obtain Ginkgo leaf stock solution.

[0067] Comparative Example 1: A Ginkgo Leaf Extract

[0068] Referring to Example 1, the difference from Example 1 is that the preparation method of Ginkgo biloba extract in step (1) is different, while the other steps are the same as in Example 1;

[0069] The preparation method of ginkgo leaf extract is as follows: mature ginkgo leaves after the White Dew season are picked from 3-year-old dwarfed saplings. After drying at 60℃ to a moisture content of 5%, dried ginkgo leaves are obtained. The dried ginkgo leaves are mixed with 60% ethanol (the mass ratio of ginkgo leaves to ethanol is 1:20), soaked at 25℃ for 1 hour, heated to 60℃ and soaked for 3 hours, filtered, and the filtrate is collected to obtain ginkgo leaf extract.

[0070] Comparative Example 2: A Ginkgo Leaf Extract

[0071] Referring to Example 1, the difference from Example 1 is that the preparation method of Ginkgo biloba extract in step (1) is different, while the other steps are the same as in Example 1;

[0072] The preparation method of ginkgo leaf extract is as follows: Mature ginkgo leaves after the White Dew solar term are picked from 3-year-old dwarfed saplings and dried at 60℃ to a moisture content of 5% to obtain dried ginkgo leaves. The dried ginkgo leaves are mixed with 60LoV (alcohol content) pure grain liquor (the mass ratio of dried ginkgo leaves to pure grain liquor is 1:20), soaked at room temperature for 4 hours, filtered, and the filtrate is collected to obtain ginkgo leaf extract; other steps are the same as in Example 1.

[0073] Comparative Example 3: A Ginkgo Leaf Extract

[0074] Referring to Example 1, the difference from Example 1 is that in step (2), zinc ammonium sulfate and sodium dihydrogen phosphate are not added; the other steps are the same as in Example 1.

[0075] Comparative Example 4: A Ginkgo Leaf Extract

[0076] Referring to Example 1, the difference from Example 1 is that humic acid is not added in step (2); the other steps are the same as in Example 1.

[0077] Comparative Example 5: A compound fertilizer

[0078] Mix 0.5 kg of zinc ammonium sulfate, 0.6 kg of potassium alginate, 0.4 kg of humic acid, and 0.2 kg of sodium dihydrogen phosphate to obtain a compound fertilizer.

[0079] Example 4: A Flavonoid-Rich Plant Nutrient Fertilizer

[0080] Pure grain yeast liquid: Soak sorghum in a mass-to-volume ratio of 1:3 for 30 minutes, remove the grain and steam it at 100℃ for 40 minutes to obtain cooked grain. When the temperature drops naturally to 35℃, mix the cooked grain with yeast in a mass ratio of 250:1 and ferment at room temperature for 8 days to obtain fermentation product. Mix the fermentation product with water in a mass ratio of 1:3, seal and ferment for 21 days. Filter and take the filtrate as pure grain yeast liquid.

[0081] Flavonoid-rich plant nutrient fertilizer: 9 kg of ginkgo leaf extract as described in Example 1 and 6 kg of pure grain yeast extract were mixed to prepare flavonoid-rich plant nutrient fertilizer.

[0082] Example 5: A Flavonoid-Rich Plant Nutrient Fertilizer

[0083] The preparation of pure grain yeast liquid is described in Example 4;

[0084] Flavonoid-rich plant nutrient fertilizer: 6 kg of ginkgo leaf extract as described in Example 2 and 9 kg of pure grain yeast extract were mixed to prepare flavonoid-rich plant nutrient fertilizer.

[0085] Example 6: A Flavonoid-Rich Plant Nutrient Fertilizer

[0086] The preparation of pure grain yeast liquid is described in Example 4;

[0087] Flavonoid-rich plant nutrient fertilizer: 8 kg of ginkgo leaf extract as described in Example 3 and 2 kg of pure grain yeast extract were mixed to prepare flavonoid-rich plant nutrient fertilizer.

[0088] Comparative Example 6: A compound fertilizer

[0089] Referring to Example 4, the difference from Example 4 is that the ginkgo leaf extract is replaced with the ginkgo leaf extract described in Comparative Example 1.

[0090] Comparative Example 7: A compound fertilizer

[0091] Referring to Example 4, the difference from Example 4 is that the ginkgo leaf extract is replaced with the ginkgo leaf extract described in Comparative Example 2.

[0092] Comparative Example 8: A compound fertilizer

[0093] Referring to Example 4, the difference from Example 4 is that the ginkgo leaf extract is replaced with the ginkgo leaf extract described in Comparative Example 3.

[0094] Comparative Example 9: A compound fertilizer

[0095] Referring to Example 4, the difference from Example 4 is that the ginkgo leaf extract is replaced with the ginkgo leaf extract described in Comparative Example 4.

[0096] Comparative Example 10: A compound fertilizer

[0097] Referring to Example 4, the difference from Example 4 is that the ginkgo leaf extract is replaced with the compound fertilizer described in Comparative Example 5.

[0098] Experimental Example 1

[0099] 350 tea tree (Tonglu Longjing tea) cuttings (1-2 leaf stage) with uniform growth were selected and randomly divided into 7 groups (Example 1, Example 4, and Comparative Examples 6-10), with 50 plants in each group. The ginkgo leaf extract described in Example 1, the flavonoid-rich plant fertilizer described in Example 4, the compound fertilizer described in Comparative Examples 6-10, and water were mixed and diluted at a volume ratio of 1:6 and then sprayed on the leaves of the tea tree cuttings. The spraying was done twice, with an interval of 7 days. The optimal state for foliar spraying was when both sides of the leaves were evenly moistened and droplets just began to roll off. The control group was sprayed with plain water, and all other management practices were the same.

[0100] Seedling height and stem diameter were measured 14 days after the second fertilization. Routine management was then implemented until the seedlings were ready for cuttings. The survival rate was calculated 20 days after cutting. The results are shown in Table 1.

[0101] Cultivation conditions: Temperature controlled at 25-28℃, relative humidity 75-85%, cutting substrate is leaf mold: perlite: river sand = 3:2:1 (volume ratio), pH value 5.5-6.0, substrate sterilized in advance (autoclave at 121℃ for 30min);

[0102] Table 1 Results of tea seedling growth index measurement

[0103]

[0104]

[0105] As can be seen from Table 1, the tea seedlings treated with Example 4 (flavonoid-rich plant fertilizer) showed the best growth indicators in all aspects, with seedling height, stem diameter and survival rate significantly higher than all other treatment groups and the control group. This indicates that the product of this invention can significantly promote the growth of tea tree cuttings and improve their stress resistance and transplant survival rate. Example 1 (Ginkgo leaf extract) showed the second best effect, indicating that the addition of pure grain yeast liquid has a synergistic effect on promoting growth. Comparative Examples 6 (ethanol extraction) and 7 (room temperature soaking) showed poor effects, proving the key role of pure grain liquor as an extractant and the step-temperature extraction process in the dissolution of effective components. Comparative Example 8 (deficient in Zn and P) showed the worst effect, even lower than some comparative examples, highlighting the core role of trace elements provided by zinc ammonium sulfate and sodium dihydrogen phosphate in promoting plant growth. Comparative Example 9 (deficient in humic acid) showed better effects than Comparative Examples 6, 7, and 8 but not as good as the examples, indicating that humic acid plays an important role in promoting growth and enhancing resistance. Comparative Example 10 (compound fertilizer only) showed a weak effect, indicating that the inorganic-organic compound fertilizer that has not been activated by Ginkgo leaf extract has limited effect.

[0106] Experiment Example 2

[0107] The experimental site was a 5-year-old tea garden in Hangzhou, Zhejiang Province, and the tea variety was Tonglu Longjing tea.

[0108] The experiment consisted of 8 treatment groups, with each treatment replicated 3 times, and the plot area was 30m². 3 The ginkgo leaf extract described in Example 1, the flavonoid-rich plant fertilizer described in Example 4, the compound fertilizer described in Comparative Examples 6-10, and water were mixed and diluted at a volume ratio of 1:6 and then sprayed on the leaves of tea cuttings. Spraying was carried out on both the first bud and the first two leaves, with a spraying amount of 150L / mu each time (the optimal state for foliar spraying is when both sides of the leaves are evenly moistened and droplets just begin to roll off); spraying with water served as the control group, and all other management practices were the same.

[0109] Five days after spraying, fresh leaves with one bud and two to three leaves were picked, processed, and dried to obtain tea. The total flavonoid content in the tea was tested, and the results are shown in Table 2.

[0110] The total flavonoid content was determined by the aluminum trichloride method (He Shumei, Liu Jinglan. Study on the determination method of total flavonoid content in tea [J]. Analytical Chemistry, 2007, (09): 1365-1368.).

[0111] Table 2. Results of total flavonoid content determination

[0112] Total flavonoid content (mg / g) Compared to CK increase Example 1 26.85±0.80 50.3％ Example 4 27.65±0.85 54.8％ Comparative Example 6 22.90±0.70 28.2％ Comparative Example 7 21.50±0.65 20.4％ Comparative Example 8 20.10±0.60 12.5％ Comparative Example 9 24.80±0.75 38.9％ Comparative Example 10 19.45±0.55 8.9％ Control group (CK) 17.86±0.50 -

[0113] As shown in Table 2, after spraying with Examples 4 and 1, the total flavonoid content in tea leaves was significantly higher than that of other treatment groups and the control group, with increases of 54.8% and 50.3%, respectively. This fully demonstrates that the products described in the examples can effectively promote the enrichment of flavonoids in tea trees. The flavonoid content of Comparative Examples 6 and 7 was significantly lower than that of the examples, which again verified the importance of optimizing the extraction process for obtaining highly active extracts. The flavonoid content of Comparative Example 8 (deficient in Zn and P) was the lowest, indicating that trace elements such as zinc and phosphorus play a crucial role in the biosynthesis pathway of flavonoids. The effect of Comparative Example 9 (deficient in humic acid) was better than most of the comparative examples, but not as good as the examples, indicating that humic acid may indirectly promote the synthesis of flavonoids by improving the soil environment or the physiological state of plants.

[0114] Experimental Example 3

[0115] An experiment was conducted in a field of Qingzhong plantations in Suzhou, with 8 treatment groups, each treatment replicated 3 times, and each plot area being 30m². 3 The ginkgo leaf extract described in Example 1, the flavonoid-rich plant fertilizer described in Example 4, the compound fertilizer described in Comparative Examples 6-10, and water were mixed and diluted at a volume ratio of 1:5. The mixture was then applied to the roots once during the seedling stage (4-5 true leaves), with an application rate of 150 ml / plant. Next, during the mid-seedling stage, the mixture was diluted with water at a volume ratio of 1:6 and sprayed on the leaves twice, 7 days apart, at a rate of 50 L / acre (the optimal state for foliar spraying is when both sides of the leaves are evenly moistened and droplets just begin to roll off). A control group was sprayed with plain water; all other management practices were the same.

[0116] Suzhou green plants were harvested after maturity, and their plant height, yield, and total flavonoid content were measured. The results are shown in Table 3.

[0117] The method for detecting total flavonoid content is as follows: Fresh vegetable leaves are dried at 100°C to obtain a dried product with a moisture content of less than 6%, and then the content is tested according to the method described in Example 3.

[0118] Table 3 Results of growth index measurement in Suzhou Qing

[0119] Plant height (cm) Yield (kg / mu) Total flavonoid content (mg / g) Example 1 25.6±1.2 2850±105 4.75±0.20 Example 4 27.8±1.5 3025±115 4.95±0.22 Comparative Example 6 22.5±1.0 2450±95 3.95±0.15 Comparative Example 7 21.8±1.1 2380±90 3.75±0.14 Comparative Example 8 20.5±0.9 2250±85 3.45±0.12 Comparative Example 9 24.2±1.1 2650±100 4.35±0.18 Comparative Example 10 19.8±0.8 2180±80 3.35±0.11 Control group (CK) 19.2±0.8 2100±75 3.25±0.10

[0120] As can be seen from Table 3, the application of the methods described in Examples 1 and 4 can significantly promote the growth and development of Suzhou green, increase yield, and greatly increase the flavonoid content of its edible parts, achieving the dual effect of increasing yield and quality. Example 4 has the best effect, with a yield increase of about 44% and a flavonoid content increase of about 52.3% compared with the control group.

[0121] Experiment Example 4

[0122] The experiment was conducted in a lettuce growing field, with 8 treatment groups, each treatment replicated 3 times, and the plot area was 30m². 3The ginkgo leaf extract described in Example 1, the flavonoid-rich plant fertilizer described in Example 4, the compound fertilizer described in Comparative Examples 6-10, and water were mixed and diluted at a volume ratio of 1:6 and sprayed once each during the mid-growth stage and the fleshy stem formation stage of lettuce. The spraying amount was 60L / mu each time (the optimal state for foliar spraying is when both sides of the leaves are evenly moistened and droplets just begin to roll off); spraying with water served as the control group, and all other management practices were the same.

[0123] After the lettuce matured, it was harvested, and the weight of a single lettuce plant, the diameter of the main stem, the yield, and the total flavonoid content were measured. The results are shown in Table 4.

[0124] The method for detecting total flavonoid content is as follows: Fresh vegetable leaves are dried at 100°C to obtain a dried product with a moisture content of less than 6%, and then the content is tested according to the method described in Example 3.

[0125] Table 4 Results of lettuce growth index measurement

[0126]

[0127]

[0128] As can be seen from Table 4, the product described in the examples has a very significant effect on increasing the thickness and weight (yield) of lettuce, and can also effectively increase the flavonoid content in lettuce. The lettuce single plant weight, main stem diameter and yield of the treatment group in Example 4 were the highest, which were 46.9%, 45.9% and 50.2% higher than those of the control group, respectively; the flavonoid content increased by 53.4%. The absence of any key process or component (Comparative Examples 6-10) will lead to a decrease in the product effect, especially when there is a lack of trace elements (Comparative Example 8), the effect is the worst.

[0129] As can be seen from the above embodiments, this invention provides a ginkgo leaf extract, a flavonoid-rich plant fertilizer, its preparation method, and its application. This invention uses pure grain liquor as the extraction solvent and employs a stepped temperature control soaking process, which effectively extracts flavonoids and other active substances from ginkgo leaves while reducing the damage of heat-sensitive components to high temperatures, thus improving extraction efficiency and the integrity of active ingredients. Based on the extract, zinc ammonium sulfate, potassium alginate, humic acid, and sodium dihydrogen phosphate are scientifically compounded to prepare the ginkgo leaf extract, which can promote plant growth, improve stress resistance, increase flavonoid accumulation, and enhance yield. The ginkgo leaf extract, combined with pure grain yeast extract, forms a nutrient fertilizer that fully leverages the advantages of combining organic and inorganic components and integrating nutrition with biostimulation, effectively increasing the total flavonoid content in crops while significantly promoting crop growth and increasing crop yield.

[0130] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing Ginkgo biloba extract, characterized in that, Includes the following steps: (1) Mix dried ginkgo leaves with pure grain liquor and soak at 20-30℃ for 0.5-1.5h, then heat to 50-60℃ and soak for 2-3h. Filter and take the filtrate to obtain ginkgo leaf extract. (2) After cooling the Ginkgo leaf extract to 25-30℃, mix it with zinc ammonium sulfate, potassium alginate, humic acid and sodium dihydrogen phosphate, stir and let it stand to obtain the original Ginkgo leaf solution.

2. The preparation method according to claim 1, characterized in that, In step (1), the mass ratio of the dried ginkgo leaves and pure grain liquor is 1:15 to 25.

3. The preparation method according to claim 1, characterized in that, In step (2), the mass ratio of ginkgo leaf extract to zinc ammonium sulfate is 1:0.04 to 0.06; The mass ratio of potassium alginate to ginkgo leaf extract is 1:0.05-0.07; The mass ratio of ginkgo leaf extract to humic acid was 1:0.03–0.

05. The mass ratio of ginkgo leaf extract to sodium dihydrogen phosphate is 1:0.015 to 0.

025.

4. The preparation method according to claim 1, characterized in that, In step (2), the stirring speed is 250-350 rpm; the stirring time is 15-25 min.

5. The preparation method according to claim 1, characterized in that, In step (2), the settling time is 2 to 3 hours.

6. Ginkgo biloba extract prepared by the preparation method according to any one of claims 1 to 5.

7. The application of the ginkgo leaf extract prepared by the preparation method according to any one of claims 1 to 5 or the ginkgo leaf extract according to claim 6 in the preparation of fertilizers that increase the total flavonoid content of crops and increase crop yield.

8. A flavonoid-rich plant nutrient fertilizer, characterized in that, It includes the following components in parts by weight: 2-4 parts ginkgo leaf extract, 1-3 parts pure grain yeast extract; The ginkgo leaf extract is the ginkgo leaf extract prepared by the preparation method according to any one of claims 1 to 5 or the ginkgo leaf extract according to claim 6.

9. The flavonoid-rich plant fertilizer according to claim 8, characterized in that, The pure grain yeast liquid is prepared by solid-state fermentation with grain as the main component. The grain is one of rice, sorghum, highland barley, or barley.

10. The method for preparing the flavonoid-rich plant nutrient fertilizer according to claim 8 or 9, characterized in that, The process includes the following steps: mixing ginkgo leaf extract and pure grain yeast extract to obtain flavonoid-rich plant fertilizer.

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