Planting method for improving content of effective components of liquorice

Abstract

The invention provides a planting method for increasing the content of effective components of liquorice, and belongs to the technical field of Chinese herbal medicine planting. The planting method comprises the steps that 1.6-2.4 kg of mineral source humic acid fertilizer is applied per mu from June to August, and 1.6-2.4 kg of microelement water-soluble fertilizer is applied per mu after 7-10 days; the trace element water-soluble fertilizer contains more than or equal to 5% of zinc, manganese, calcium, magnesium, iron and molybdenum. The soil microenvironment is improved through humic acid, root development and secondary metabolism precursor accumulation are promoted, photosynthesis and secondary metabolism pathways are accurately activated in combination with microelements, the content of glycyrrhizic acid and liquiritin is synergistically increased, effective components of the licorice medicinal material meet the requirements of Chinese Pharmacopoeia, and ecological management and medicinal material efficient production value are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of Chinese herbal medicine planting, and in particular relates to a planting method for increasing the content of effective components in liquorice. Background Art

[0002] Licorice ( Glycyrrhiza uralensis Fisch., a perennial herb in the Leguminosae family, is a core component of traditional Chinese medicine. Its roots and rhizomes are rich in active ingredients such as glycyrrhizic acid and liquiritin, which have been shown to exhibit multiple pharmacological effects, including anti-inflammatory, antiviral, immunomodulatory, and antioxidant properties. Glycyrrhizic acid, a quality indicator component specified in the Chinese Pharmacopoeia, directly determines the grade and clinical value of licorice. Liquiritin, a representative flavonoid, has shown significant potential in alleviating neurodegenerative diseases and combating tumors.

[0003] Driven by the need for coordinated development of ecological management and medicinal material production, licorice has been widely introduced to marginal lands such as windy sandy land and desert saline-alkali land. However, such adverse environments seriously restrict the synthesis efficiency of licorice secondary metabolites. The poor water and fertilizer retention capacity of windy sandy land leads to the stunted development of the root system and reduces the production of glycyrrhizic acid synthesis precursors; the high concentration of Na in desert saline-alkali land + Inhibits tonoplast H + -ATPase activity, destroying the pH homeostasis of key organelles for glycyrrhizin biosynthesis; the large temperature difference between day and night in sandy land and the osmotic stress of saline-alkali land prompt the plants to initiate stress response prematurely, tilting metabolic resources to osmotic regulating substances such as proline, resulting in a 30%-50% decrease in the carbon flow allocation rate of the glycyrrhizic acid synthesis pathway.

[0004] Existing research shows that, over the same growing years, the glycyrrhizic acid content of licorice cultivated on sandy land is 40%-60% lower than that of licorice grown in traditional cultivation areas, while the glycyrrhizin content in saline-alkali land is only one-third to one-half of that of licorice grown on farmland. Although such marginal lands can meet the basic survival needs of licorice, conventional agronomic practices such as flat-bed sowing and extensive irrigation cannot reverse the inhibitory effects of secondary metabolism. As a result, the produced medicinal material fails to meet the qualified product thresholds of glycyrrhizic acid ≥2.0% and glycyrrhizin ≥0.05% specified in the Chinese Pharmacopoeia, severely restricting the sustainable development of the ecologically economic licorice industry. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide a planting method for increasing the content of effective ingredients in licorice, by applying mineral humic acid fertilizer and trace element fertilizer, thereby increasing the content of glycyrrhizic acid and liquiritin in licorice to meet the requirements of the Chinese Pharmacopoeia.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: A planting method for increasing the content of effective ingredients in licorice comprises applying 1.6-2.4 kg / mu of mineral humic acid fertilizer from June to August, and applying 1.6-2.4 kg / mu of trace element water-soluble fertilizer 7-10 days later; the trace element water-soluble fertilizer contains zinc, manganese, calcium, magnesium, iron and molybdenum by ≥5wt%.

[0007] Preferably, the licorice planting land is sandy land or desert saline-alkali land.

[0008] Preferably, the licorice includes Glycyrrhiza uralensis, Glycyrrhiza inflata and Glycyrrhiza glabra.

[0009] Preferably, the effective ingredients of licorice include glycyrrhizic acid and liquiritin.

[0010] Preferably, the mineral humic acid fertilizer is applied from June to August when the temperature is 25-30° C. and the licorice plant height is 30-50 cm.

[0011] More preferably, the mineral-source humic acid fertilizer is applied by drip irrigation, once or twice; the interval between the two applications is 25-35 days.

[0012] Preferably, the trace element water-soluble fertilizer is applied by spraying 2-4 times, with an interval of 7-10 days between each application.

[0013] More preferably, the mineral-source humic acid fertilizer or trace element water-soluble fertilizer is diluted and applied, and the amount of water used for dilution is 20-30 t / mu.

[0014] Preferably, the mineral-source humic acid fertilizer and trace element water-soluble fertilizer are continuously applied every year until the licorice is harvested.

[0015] Preferably, the licorice is sown by direct seeding at a density of 100,000 to 200,000 plants per mu; or transplanted by seedlings at a transplanting density of 14,000 to 22,000 plants per mu.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This method combines mineral-derived humic acid fertilizer with trace element water-soluble fertilizer to improve the soil environment and activate licorice's secondary metabolic pathways, significantly increasing the content of glycyrrhizic acid and liquiritin, bringing the active ingredients of the medicinal material to the standards set by the Chinese Pharmacopoeia (glycyrrhizic acid ≥ 2.0%, liquiritin ≥ 0.5%), a 30%-50% increase compared to conventional cultivation. This method is particularly suitable for marginal lands such as windy sandy areas and desert saline-alkali lands, addressing issues such as soil infertility and salinity stress, promoting root development, and enhancing licorice's resistance to stress, ensuring normal growth and accumulation of active ingredients in drought and high-salt environments.

[0017] While improving the ecological environment of sandy and saline-alkali lands, the present invention can realize large-scale cultivation of high-quality licorice, reduce dependence on wild resources, and promote the coordinated development of ecological management and the traditional Chinese medicine industry. DETAILED DESCRIPTION

[0018] The present invention provides a cultivation method for increasing the content of active ingredients in licorice, comprising the following steps: applying 1.6-2.4 kg / mu of mineral-derived humic acid fertilizer from June to August, and applying 1.6-2.4 kg / mu of trace element water-soluble fertilizer 7-10 days later; the trace element water-soluble fertilizer contains ≥5 wt% of zinc, manganese, calcium, magnesium, iron, and molybdenum. The mineral-derived humic acid fertilizer creates a suitable growth microenvironment by "improving soil, promoting root growth, and regulating metabolism," while the trace element water-soluble fertilizer precisely regulates secondary metabolic pathways by "supplementing, activating, and stabilizing enzyme activity." The two methods work synergistically in specific habitats and growth periods to increase the content of active ingredients in licorice.

[0019] In the present invention, the preferred application amount of mineral-source humic acid fertilizer is 1.6-1.8 kg / mu, 1.8-2.2 kg / mu, or 2.2-2.4 kg / mu, more preferably 1.9-2.1 kg / mu, and more preferably 2 kg / mu. The preferred application amount of trace element water-soluble fertilizer is 1.6-1.8 kg / mu, 1.8-2.2 kg / mu, or 2.2-2.4 kg / mu, more preferably 1.9-2.1 kg / mu, and more preferably 2 kg / mu. The present invention does not particularly limit the sources of mineral-source humic acid fertilizer and trace element water-soluble fertilizer, and both can be obtained through market channels.

[0020] In the present invention, the licorice planting site is preferably a sandy land or a desert saline-alkali land, and further preferably the planting site is equipped with sprinkler irrigation and drip irrigation facilities; preferably, the effective ingredients of licorice include glycyrrhizic acid and liquiritin.

[0021] The soil in sandy land / desert saline-alkali land is poor and has poor water and fertilizer retention capacity. Humic acid can increase soil aggregates, increase porosity, improve air permeability through colloidal adsorption, and create a suitable environment for root growth; lower the pH value of saline-alkali land and reduce sodium ion toxicity; chelate heavy metals, reduce the fixation of ineffective nutrients in the soil, and improve the effectiveness of mineral elements; it can also stimulate the activity of root meristems, increase the number of root hairs, expand the absorption area, and enhance the root system's ability to absorb water and nutrients, providing a material basis for licorice growth and secondary metabolism; humic acid also promotes stem and leaf growth and the accumulation of photosynthetic products by affecting the balance of hormones such as auxin and cytokinin, while inducing the activity of enzymes related to secondary metabolism, and promoting the accumulation of synthetic precursors of glycyrrhizic acid and glycyrrhizin.

[0022] Zinc participates in auxin synthesis, promoting root development and stem and leaf growth, and indirectly increasing the transport of photosynthate products to the roots. As a coenzyme for carbonic anhydrase and superoxide dismutase, it maintains cellular redox balance, reduces free radical damage, and ensures the activity of secondary metabolic enzymes. Manganese, a core component of the photosynthetic light system, promotes light energy conversion and ATP synthesis, providing energy for secondary metabolism. It also activates key enzymes in the tricarboxylic acid cycle, promoting the conversion of pyruvate to acetyl-CoA, providing a precursor for glycyrrhizic acid synthesis. Calcium stabilizes cell membrane structure, regulates ion channels, maintains intracellular calcium signaling, participates in signal regulation for the synthesis of secondary metabolites, and indirectly promotes the accumulation of saponins. Magnesium, the central ion in the chlorophyll molecule, directly influences photosynthetic efficiency, increases photosynthate synthesis, and provides the carbon skeleton and energy for secondary metabolism. Iron participates in the chloroplast electron transport chain and ferredoxin synthesis, promoting photosynthetic electron transport and NADPH production, providing a reducing agent for secondary metabolic reduction reactions. Molybdenum acts as a coenzyme for nitrate reductase and nitrogenase, promoting nitrogen metabolism, improving the efficiency of amino acid and protein synthesis, and participating in the regulation of key enzymes in the flavonoid synthesis pathway.

[0023] In the present invention, preferably, licorice includes uralensis, inflated fruit licorice and glabra licorice. The present invention has no specific limitation on the source of the above licorice varieties, which can be varieties promoted in the planting area or local wild species.

[0024] In the present invention, mineral-source humic acid fertilizer is preferably applied from June to August, when the temperature is 25-30°C and the licorice plant height is 30-50 cm; further preferably, it is applied at a temperature of 28°C and the licorice plant height is 35-45 cm. June to August is the period of rapid growth of the aboveground parts of licorice and the expansion of the root system. Applying mineral-source humic acid at this time can optimize the root environment and reserve nutrients for the effective component accumulation period in the roots from August to October. Seven to ten days after application, mineral-source humic acid supplements trace elements, just in time to meet the peak demand for mineral elements in the stem and leaf photosynthetic system and the secondary metabolism of the roots.

[0025] In the present invention, the mineral-source humic acid fertilizer is preferably applied by drip irrigation, once or twice; the interval between the two applications is 25-35 days, more preferably 30 days.

[0026] In the present invention, the water-soluble trace element fertilizer is preferably applied by spraying 2-4 times, more preferably 3-4 times, with an interval of 7-10 days between each application.

[0027] In the present invention, it is preferred that the mineral humic acid fertilizer or the trace element water-soluble fertilizer be diluted and applied, and the amount of water used for dilution is 20-30 t / mu, more preferably 25 t / mu.

[0028] In the present invention, it is preferred that mineral-derived humic acid fertilizer and trace element water-soluble fertilizer be applied continuously annually until the licorice is harvested. As an implementation method, the "Chinese Pharmacopoeia" requires that the glycyrrhizic acid content in licorice be ≥2.0% (qualified products) and liquiritin ≥0.50%. Artificially cultivated licorice usually meets this standard at 3-4 years old. In practice, in arid areas, it is usually harvested after 3 years of cultivation. In the present invention, the mineral-derived humic acid fertilizer and trace element water-soluble fertilizer are applied continuously for 3 years.

[0029] In the present invention, it is preferred that licorice be sown in the form of direct seeding, with a density of 100,000 to 200,000 plants per mu, more preferably 150,000 plants per mu, more preferably 1 film with 4 rows of seeds and a film width of 1.25m during direct seeding; or seedling transplanting is adopted, with a transplanting density of 14,000 to 22,000 plants per mu, more preferably 18,000 plants per mu. The present invention more preferably adopts the form of seedling transplanting in desert saline-alkali land, and irrigates water before sowing to suppress alkali. Reasonable density can regulate the light competition, root development, photosynthetic product distribution and secondary metabolic pathways of licorice plants; the high-density design of direct seeding focuses on early colony establishment and land cover, while the low-density strategy of seedling transplanting focuses on the robust development of individual plants and the accumulation of effective ingredients in the roots. The preferred density of both is a balance found between yield, quality, stress resistance and management efficiency, ultimately achieving a dual increase in the content of effective ingredients in licorice and planting benefits.

[0030] The technical solutions provided by the present invention are 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.

[0031] Example 1 A method for increasing the active ingredients of licorice, comprising the following steps: Planting site: sandy land, soil pH 7.8, organic matter content 0.8%, salt content 0.15%; Licorice varieties: Ural liquorice; Planting method and density: direct seeding, density 150,000 plants / mu, sowing in 4 rows per film, film width 1.25m, row spacing 30cm; Fertilization management: (1) Mineral humic acid fertilizer: In July (average daily temperature 28°C, licorice plant height 40 cm), apply 1 kg / mu by drip irrigation for the first time, and apply 1 kg / mu again after 30 days. The dilution water consumption for each drip irrigation is 25 t / mu. (2) Trace element water-soluble fertilizer (zinc, manganese, calcium, magnesium, iron and molybdenum ≥ 5%): 7 days after the first drip irrigation of mineral humic acid fertilizer, spray it 4 times in a row, each time at 0.5 kg / mu, with an interval of 7 days between each spraying, and the dilution water consumption for each spraying is 25 t / mu; Apply the above fertilizers continuously every year until the harvest in the third year, combining drip irrigation and spraying throughout the process.

[0032] Example 2 A method for increasing the active ingredients of licorice, comprising the following steps: Planting site: desert saline-alkali land, soil pH 8.5, salt content 0.3%; Licorice varieties: Licorice inflated fruit; Planting method and density: transplanting seedlings, density 18,000 plants / mu, irrigating before sowing to suppress alkali (irrigation volume 80m 3 / mu); Fertilization management: (1) Mineral humic acid fertilizer: In June (average daily temperature 25°C, licorice plant height 35 cm), drip irrigation was used at 1.6 kg / mu, and the dilution water volume for drip irrigation was 20 t / mu; (2) Trace element water-soluble fertilizer (zinc, manganese, calcium, magnesium, iron and molybdenum ≥ 5%): After 10 days of drip irrigation of mineral humic acid fertilizer, spray it three times continuously, each time at 0.6 kg / mu, with an interval of 10 days between each spraying, and the dilution water consumption for each spraying is 20 t / mu; Apply the above fertilizers continuously every year until harvest, combining drip irrigation and spraying throughout the process.

[0033] Example 3 A method for increasing the active ingredients of licorice, comprising the following steps: Planting site: Sandy and slightly saline, soil pH 8.0, salt content 0.2%; Licorice varieties: Glycyrrhiza glabra and Glycyrrhiza uralensis mixed in a ratio of 1:1; Planting method and density: direct seeding, density 180,000 plants / mu, sowing in 4 rows per film, film width 1.25m, row spacing 30cm; Fertilization management: (1) Mineral humic acid fertilizer: In August (average daily temperature 30°C, licorice plant height 50 cm), the first drip irrigation was applied at 1.2 kg / mu, and 25 days later, the second drip irrigation was applied at 1.2 kg / mu. The dilution water consumption for each drip irrigation was 30 t / mu. (2) Trace element water-soluble fertilizer (zinc, manganese, calcium, magnesium, iron and molybdenum ≥ 5%): 8 days after the first drip irrigation of mineral humic acid fertilizer, spray it twice in a row, each time at 1.2 kg / mu, with an interval of 8 days between each spraying, and the dilution water consumption for each spraying is 30 t / mu; Apply the above fertilizers continuously every year until the harvest in the third year, combining drip irrigation and spraying throughout the process.

[0034] Test Example 1 Effects of Fertilization Types on the Content of Active Ingredients in Licorice 1. Test location The soil type in Yugong Township, Korlahala is sandy, with high salinity and low organic matter, nitrogen, phosphorus and potassium content. Due to continuous cotton cropping, there are problems such as soil compaction, malignant weeds and serious soil-borne diseases.

[0035] 2. Experimental Design Planted varieties: Glycyrrhiza uralensis and Glycyrrhiza uralensis (both from wild sources).

[0036] Planting mode: Direct seeding without film, sowing in May 2018.

[0037] Experimental groups (50 mu per group): Experimental group: water-soluble fertilizer containing trace elements (containing zinc, manganese, calcium, magnesium, iron, and molybdenum ≥ 5%), mineral humic acid fertilizer, monoammonium phosphate, urea, and potassium dihydrogen phosphate were applied respectively; Control group: No test fertilizer was applied, only routine management was applied.

[0038] Fertilization method: In July every year, drip irrigation is carried out twice with mineral humic acid fertilizer, 1 kg / mu each time, with an interval of 30 days; in July every year, spraying of trace element water-soluble fertilizer is carried out four times, 0.5 kg / mu each time, with an interval of 7 days; the application amount of monoammonium phosphate, urea and potassium dihydrogen phosphate is 2.0 kg / mu each.

[0039] 3. Sample collection and testing The tea is collected from randomly selected sites in October and November every year (≥9 sites per mu, ≥1kg per site), and the above-ground parts are removed and then dried in a cool and shady place. The content of glycyrrhizic acid and glycyrrhizin is tested according to the 2015 edition of the Chinese Pharmacopoeia.

[0040] 4. Test results As shown in Table 1, compared with the control (CK), the application of trace element water-soluble fertilizers and mineral-derived humic acid fertilizers significantly increased the glycyrrhizic acid and liquiritin content in Glycyrrhiza uralensis and Glycyrrhiza uralensis, with this trend continuing to increase with age. The most significant effect of the trace element water-soluble fertilizers was observed: the glycyrrhizic acid content in Glycyrrhiza uralensis increased from 2.30% in 2018 to 3.90% in 2020, and the liquiritin content increased from 0.65% to 1.05%; while the glycyrrhizic acid content in Glycyrrhiza uralensis increased from 2.35% to 3.75%, and the liquiritin content increased from 0.65% to 1.15%. Mineral-derived humic acid fertilizers performed second best, with Glycyrrhiza uralensis reaching 2.80% glycyrrhizic acid and 0.85% liquiritin in 2020, and Glycyrrhiza uralensis reaching 2.85% glycyrrhizic acid and 1.05% liquiritin in 2020. However, monoammonium phosphate, urea, and potassium dihydrogen phosphate did not significantly increase the active ingredients of the two licorice root varieties. In 2020, the highest glycyrrhizic acid content was only 2.45% (Ural Glycyrrhiza uralensis, potassium dihydrogen phosphate group), and the highest glycyrrhizin content was 0.55% (same group), both lower than the trace element and humic acid groups. Furthermore, the above licorice root varieties were tested for pesticide residues, heavy metals, and harmful elements, and met the requirements for glycyrrhizic acid monoammonium salt in the 2015 Pharmacopoeia. Glycyrrhizic acid powder and glycyrrhizic acid monoammonium salt manufactured from the above batches of licorice were also tested for other indicators listed in the Pharmacopoeia and met the requirements for glycyrrhizic acid monoammonium salt in the 2015 Pharmacopoeia.

[0041] Table 1 Effects of fertilizer types on the content of active ingredients in licorice

[0042] Test Example 2 Effect of Fertilization Time on the Content of Active Ingredients in Licorice 1. Test location The soil and environmental conditions were the same as those in Test Example 1.

[0043] 2. Experimental Design Planted varieties: Glycyrrhiza uralensis and Glycyrrhiza uralensis (both from wild sources).

[0044] Planting mode: Direct seeding without film, sowing in May 2018.

[0045] Experimental groups (50 mu per group): Experimental group: mineral humic acid fertilizer (2.0 kg / mu) + trace element water-soluble fertilizer (2.0 kg / mu) were applied in June, July and August each year; Control group: drip irrigation with clean water, no test fertilizer was applied.

[0046] Fertilization method: drip irrigation (applied through the first fertilizer tank of field drip irrigation), once a year, applied in the corresponding month.

[0047] 3. Sample collection and testing Same as Test Example 1.

[0048] 4. Test results As shown in Table 2, there were significant differences in the effects of applying mineral humic acid fertilizers and trace element water-soluble fertilizers from June to August, with August fertilization providing the greatest improvement in the active ingredients of both licorice varieties. In Glycyrrhiza inflata fertilized in August, glycyrrhizic acid content ranged from 3.50% to 3.90% and liquiritin from 0.65% to 0.85% from 2018 to 2020, significantly higher than those in the June group (2.30% to 2.50% glycyrrhizic acid, 0.55% to 0.65%) and the July group (3.20% to 3.60% glycyrrhizic acid, 0.60% to 0.75%). The August fertilization effect of Ural Glycyrrhiza uralensis was even more pronounced, with glycyrrhizic acid reaching 3.90% and liquiritin 1.50% in 2018, and 4.20% and 1.20% respectively in 2019, all significantly higher than those in the June and July groups. Furthermore, all time-dependent groups were significantly higher than the control group (with glycyrrhizic acid reaching a peak of 2.20% and liquiritin 0.45% in 2020). This also met the requirements for glycyrrhizic acid monoammonium salt in the 2015 Pharmacopoeia.

[0049] Table 2 Effect of fertilization time on the content of active ingredients in licorice

[0050] Test Example 3 Effects of Fertilizer Amount on the Content of Active Ingredients in Licorice 1. Test location The soil and environmental conditions were the same as those in Test Example 1.

[0051] 2. Experimental Design Planted varieties: Glycyrrhiza uralensis and Glycyrrhiza uralensis (both from wild sources).

[0052] Planting mode: Direct seeding without film, sowing in May 2018.

[0053] Experimental groups (50 mu per group): Experimental group: Mineral humic acid fertilizer and trace element water-soluble fertilizer were applied in synergy, with three gradients: Group A: humic acid 0.5kg / mu + trace elements 0.5kg / mu; Group B: humic acid 1kg / mu + trace elements 1kg / mu; Group C: humic acid 1.5kg / mu + trace elements 1.5kg / mu; Control group: drip irrigation with clean water, no test fertilizer was applied.

[0054] Fertilization method: drip irrigation (applied through the first fertilizer tank of field drip irrigation), applied twice in July each year.

[0055] 3. Sample collection and testing Same as Test Example 1.

[0056] 4. Test results As shown in Table 3, when mineral-derived humic acid fertilizers are applied in conjunction with water-soluble trace element fertilizers, the fertilizer rate is positively correlated with the content of active ingredients. However, the difference between the high-dose (1.5 kg humic acid + 1.5 kg trace element) and medium-dose (1 kg humic acid + 1 kg trace element) dosages is relatively small. In 2020, the medium-dose group of Glycyrrhiza inflata reached 4.50% glycyrrhizic acid and 0.85% liquiritin, while the high-dose group had 4.60% and 0.90%, respectively, significantly higher than the low-dose group (3.50% and 0.75%). In 2020, the medium-dose group of Glycyrrhiza uralensis had 4.20% glycyrrhizic acid and 1.10% liquiritin, while the high-dose group had 4.30% and 1.20%, respectively, both significantly higher than the low-dose group (3.60% and 0.75%). The active ingredients in the control group increased slowly over the three years. In 2020, the glycyrrhizic acid content in Glycyrrhiza inflata was only 2.10% and the liquiritin content was 0.25%, while that in Glycyrrhiza uralensis was 2.20% and 0.45%, respectively, both lower than those in the fertilized groups. This also meets the requirements for glycyrrhizic acid monoammonium salt in the 2015 edition of the Pharmacopoeia.

[0057] Table 3 Effect of fertilizer application on the content of active ingredients in licorice

[0058] Test Example 4 Field production experiment I The experimental area is located in Taheqiao, Yuli County, with approximately 600,000 to 800,000 mu of farmland, primarily distributed around the Tarim River basin. Irrigation methods primarily include seasonal flooding and drip irrigation, with cotton being the primary cash crop. Soil types are primarily sandy and desert saline. Desert plants predominate in the area, and before cultivation, it was a wild breeding ground for desert plants such as Populus euphratica, Licorice, Apocynum venetum, Tamarix tamarisk, and Camel Thorn. Wild licorice species are relatively limited, with only Glycyrrhiza inflata found.

[0059] Licorice cultivation began in 2019, reaching over 10,000 mu (approximately 10,000 acres). The 2019-2020 plantings featured a mixed variety, with varieties including Glycyrrhiza inflata, Ural, Glycyrrhiza glabra, and Glycyrrhiza glabra variants visible in the fields. In 2020-2021, 800 and 1,200 mu (approximately 1,000 acres) of experimental plots of Glycyrrhiza inflata were planted, respectively. In 2021, 1,600 mu (approximately 1,000 acres) of the Inner Mongolia Ural variety were planted. Because the overall glycyrrhizic acid and liquiritin content of the cultivated licorice was low and did not meet industrial processing standards, the company began using a combination of mineral-derived humic acid fertilizers and trace element water-soluble fertilizers to increase the active ingredient content of the licorice.

[0060] 1. The test site is Taichang Farm in Taheqiao. The planting mode is 1 film and 4 rows of direct seeding. The width of the ground film is 1.25m.

[0061] 2. The area and time of the test are shown in Table 4.

[0062] Table 4 Test area and time

[0063] In the table, the mixed varieties are sourced from Xinjiang, with Ural, Glycyrrhiza glabra, and Glycyrrhiza inflata found in the field. Glycyrrhiza inflata is sourced from Xinjiang and is relatively pure, with occasional Glycyrrhiza glabra found in the field. Glycyrrhiza uralensis is sourced from Inner Mongolia and is relatively pure, with only Ural in the field.

[0064] The experimental fertilizer application method is shown in Table 5. A control group was set up without applying mineral humic acid fertilizer and trace element water-soluble fertilizer.

[0065] Table 5 Fertilization method of experimental fertilizers

[0066] 3. Sample Collection: Samples were collected from randomly selected sites in the experimental fields between April and May and October and November each year. For every 1,000 mu (approximately 300 mu), at least 3 sites were selected for each site, with a sample collection volume of at least 5 kg per site.

[0067] 4. Test results As shown in Tables 6-8, drip irrigation with mineral-derived humic acid fertilizer and spraying with trace element water-soluble fertilizer significantly increased glycyrrhizic acid and liquiritin content in two- and three-year-old Glycyrrhiza uralensis. There was a modest effect on glycyrrhizic acid in Ural Glycyrrhiza uralensis, but no significant effect on liquiritin. There was some effect on glycyrrhizic acid and liquiritin content in mixed licorice varieties, but the effect was somewhat lower than that in Glycyrrhiza uralensis. The experiments also tested other indicators listed in the Pharmacopoeia for these various licorice sources, and the results were consistent with the 2015 Pharmacopoeia regulations for licorice, with no excessive levels of pesticide residues, heavy metals, or harmful elements.

[0068] In addition, the trial also conducted 20 batches of large-scale production trials of glycyrrhizic acid powder from mixed varieties. The average yield of glycyrrhizic acid powder was 8.70%, with an average glycyrrhizic acid content of 26.5%. The quality and yield of glycyrrhizic acid powder were comparable to those of wild Xinjiang Glycyrrhiza uralensis. Subsequently, large-scale production trials of glycyrrhizic acid monoammonium salt were conducted using glycyrrhizic acid powder, which showed similar results to glycyrrhizic acid powder imported from Uzbekistan. The glycyrrhizic acid monoammonium salt produced from the above glycyrrhizic acid powder was also tested for other pharmacopoeial indicators, which met all requirements for glycyrrhizic acid monoammonium salt in the 2015 edition of the Pharmacopoeia.

[0069] Table 6 Changes in effective components of licorice before and after fertilization in 2021

[0070] Table 7 Changes in effective components of licorice before and after fertilization in 2022

[0071] Table 8 Changes in effective components of licorice before and after fertilization in 2023

[0072] Test Example 2 Field Production Trial II The experimental area is near the Grand Canyon in Yuli County. Licorice cultivation began in 2021, with a planting area of ​​300 mu, and the Ural licorice variety was planted. The soil types in this area are mainly sandy soil and desert saline soil, with high salinity and relatively low organic matter, nitrogen, phosphorus and potassium. In addition, irrigation water is limited to watering, resulting in large-scale secondary salinization of the soil in the region. The distributed plants are mainly desert plants. Before reclamation, it was a wild breeding ground for desert plants such as poplar, licorice, apocynum venetum, red willow, camel thorn, and reed. This area is located in the east wind direction of Korla, and the year-round sandstorm damage is more serious than other areas. The main purpose of choosing licorice planting is to improve the soil. There is a concern that the quality of artificial cultivation will be low. Therefore, mineral humic acid fertilizers and trace element water-soluble fertilizers are selected to improve the quality of licorice.

[0073] 1. Experimental purpose: To analyze the effects of applying mineral humic acid fertilizer and trace element water-soluble fertilizer on the content of effective ingredients of two provenances of Ural Glycyrrhiza uralensis artificially cultivated.

[0074] 2. Basic information of the test site (2.1) Test location: Grand Canyon, Yuli County; (2.2) Soil conditions: The terrain is relatively flat and was in a desertified state before development. There are no drainage channels for farmland. The soil types are aeolian sandy soil and desert saline soil, with high salinity and relatively low organic matter, nitrogen, phosphorus and potassium. (2.3) Climate: Temperate continental arid climate with an average frost-free period of 210 days, hot summers, high evaporation, drought and little rainfall; (2.4) Plant distribution: There are some remnants of desert plants such as Populus euphratica, Licorice, Apocynum venetum, and Phragmites australis in the area.

[0075] 3. Field experiment design (3.1) Test variety: Ural Glycyrrhiza uralensis, the seed sources are wild species in Inner Mongolia and wild species in Yanqi County.

[0076] (3.2) Field selection: The field is basically a 50-mu strip field, which is relatively standardized. The experimental group and the blank control group are randomly selected.

[0077] (3.3) Experimental planting mode: The planting mode is direct seeding mode, 1 film and 4 rows of seeds, the width of the ground film is 1.25m; the irrigation method is drip irrigation.

[0078] (3.5) The fertilization method is shown in Table 9, and the fertilization period is 2021-2023.

[0079] Table 9 Two methods of fertilizing Ural licorice

[0080] (3.6) Sample Collection: Samples shall be collected from randomly selected fields between April and May and October and November each year, depending on the test variety. Samples shall be collected from at least 15 sites per variety, with a minimum sample volume of 2 kg per site.

[0081] 4. Test results As shown in Table 10, the application of mineral-derived humic acid fertilizers and trace element water-soluble fertilizers significantly increased the active ingredients glycyrrhizic acid and liquiritin in Ural Glycyrrhiza uralensis over its three-year growth cycle, with both levels meeting the national pharmacopoeia standards. Significant differences in active ingredient content were observed between the experimental and control groups of Inner Mongolia Ural Glycyrrhiza uralensis and Yanqi County Ural Glycyrrhiza uralensis, with some differences also observed between the two provenances. Ural Glycyrrhiza uralensis from these sources was also tested for other pharmacopoeial indicators, which met all requirements under the 2015 Pharmacopoeia for licorice, including pesticide residues, heavy metals, and hazardous elements.

[0082] Table 10 Changes in effective components of licorice before and after fertilization from 2021 to 2023

[0083] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for increasing the content of effective ingredients in liquorice, characterized in that: The following steps are involved: Apply 1.6-2.4 kg / mu of mineral humic acid fertilizer from June to August, and apply 1.6-2.4 kg / mu of trace element water-soluble fertilizer 7-10 days later; the trace element water-soluble fertilizer contains zinc, manganese, calcium, magnesium, iron and molybdenum ≥5wt%.

2. The planting method according to claim 1, characterized in that The licorice planting land is a sandy land or a desert saline-alkali land.

3. The planting method according to claim 1, characterized in that The licorice includes uralensis, inflated fruit licorice and glabra fruit licorice.

4. The planting method according to claim 1, characterized in that The effective ingredients of licorice include glycyrrhizic acid and liquiritin.

5. The planting method according to claim 1, characterized in that: The mineral humic acid fertilizer is applied from June to August when the temperature is 25-30° C. and the licorice plant height is 30-50 cm.

6. The planting method according to claim 1 or 5, characterized in that: The mineral-source humic acid fertilizer is applied by drip irrigation, once or twice; the interval between the two applications is 25-35 days.

7. The planting method according to claim 1, characterized in that: The trace element water-soluble fertilizer is applied by spraying 2-4 times, with an interval of 7-10 days between each application.

8. The planting method according to claim 1, characterized in that: The mineral humic acid fertilizer or trace element water-soluble fertilizer is diluted and applied, and the dilution water consumption is 20-30t / mu.

9. The planting method according to claim 1, characterized in that: The mineral-source humic acid fertilizer and the trace element water-soluble fertilizer are continuously applied every year until the licorice is harvested.

10. The planting method according to claim 1, characterized in that: The licorice is planted by direct seeding at a density of 100,000 to 200,000 plants per mu; or by transplanting seedlings at a density of 14,000 to 22,000 plants per mu.

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