Isatis indigotica cultivation method for directional root shaping and quality improvement by water and fertilizer

Abstract

The present application relates to the technical field of cultivation of radix isatidis, and is a cultivation method for water and fertilizer directional root shaping and quality improvement of radix isatidis. The cultivation method for water and fertilizer directional root shaping and quality improvement of radix isatidis combines the processes of water control and shoot suppression, high-phosphorus root elongation promotion, micro-fertilizer root strengthening, and quality improvement in drought environment. Specifically, the method first realizes directional induction of deep main root growth through three-water irrigation management in the seedling stage, then realizes vertical elongation of the main root through directional water and fertilizer management in the main root elongation period, then realizes rapid root and stem swelling and significant improvement of medicinal material quality through balanced water and fertilizer supply and micro-fertilizer supply in the main root swelling period, and finally realizes efficient accumulation of effective components through water control in the maturation period. The radix isatidis obtained by the cultivation method has straight, compact and uniform main root strips, long main roots, few fibrous roots, and high yield of first-grade products.

Description

Technical Field

[0001] This invention relates to the field of Isatis indigotica cultivation technology, and is a cultivation method for Isatis indigotica with directional water and fertilizer application to promote root growth and improve quality. Background Technology

[0002] Isatis root (also known as woad) is a widely used traditional Chinese medicine for clearing heat and detoxifying, with broad market demand and a large-scale industry. In current agricultural production practices, Isatis root cultivation generally adopts an extensive management approach with unified water and fertilizer supply and management. This traditional management model is not compatible with the stage-specific growth patterns of the Isatis root system and struggles to meet the requirements for high-quality medicinal material production. Especially in arid, semi-arid, and slightly saline-alkali areas, this extensive management model often fails to effectively cope with the complex root environment, hindering the large-scale and standardized production of Isatis root.

[0003] Current cultivation techniques still suffer from many common industry-wide defects during implementation, severely impacting the quality stability of medicinal materials. Specific defects include: First, in seedling management, there is a common problem of excessive water supply and excessive nitrogen fertilizer application, which directly leads to excessive growth of surface fibrous roots and insufficient power for the taproot to grow downward, which lays the groundwork for the taproot to be too short and the root shape to be scattered in the later stage. Secondly, after entering the elongation period, due to the unreasonable water and fertilizer ratio, a large number of lateral roots grow in disorder, resulting in a high incidence of "chicken claw roots", forked roots, and bent roots, which greatly reduces the rate of high-quality products. Third, during the swelling period, the uneven supply of nutrients leads to uneven root development, which can easily result in uneven thickness, hollowness and abnormal lignification, resulting in poor uniformity of medicinal materials. Fourth, during the mature stage, excessive water and fertilizer will cause the plant to grow excessively, and the accumulation of secondary metabolites transported to the roots will be insufficient, resulting in low content of the main medicinal components such as indigo and indirubin. Fifth, in arid and saline-alkali producing areas, conventional cultivation is difficult to adapt to large fluctuations in rhizosphere water and salt, leading to root stress disorder and extremely unstable yield and quality.

[0004] Currently, most of the publicly available patents are limited to technical aspects such as land preparation methods, weeding operations, pest and disease control, or improvement of single fertilization. For example, Chinese patent document CN109757326A discloses a high-yield, water-saving irrigation method for Isatis indigotica under mulch. This method includes the following steps: S1. Before sowing, the land is mechanically deep-plowned, and base fertilizer is applied once. The base fertilizer is phosphate fertilizer, nitrogen fertilizer, and potassium sulfate. Then the land is leveled. S2. Drip irrigation tapes are manually laid on the leveled land at 60cm intervals. S3. A 140cm wide colorless plastic film is covered over the laid drip irrigation tapes. S4. Double-row sowing is carried out on both sides of each drip irrigation tape covered with film using seeding trays, with a plant spacing of 6cm-8cm and a row spacing of 10cm-15cm. S5. While maintaining sufficient water supply during the seedling and fleshy root maturation stages, the drip irrigation tapes are used to provide water deficit irrigation during the vegetative growth and fleshy root growth stages. This invention, based on the water requirement patterns of Isatis indigotica, regulates irrigation conditions for its cultivation by implementing water deficit irrigation at different growth stages, aiming to achieve water conservation, high efficiency, and high yield. However, this technical solution primarily focuses on irrigation methods and water-saving effects, lacking consideration for the synergistic effect of water regulation and fertilizer application, and also failing to conduct in-depth research on the directional shaping effect of water regulation and precision fertilization on root structure.

[0005] Therefore, existing technologies cannot fundamentally solve the technical problems of multiple branching of the main root and poor quality of Isatis indigotica, making it difficult to achieve standardized and quantitative precision cultivation of Isatis indigotica. Summary of the Invention

[0006] This invention provides a cultivation method for Isatis indigotica with directional water and fertilizer to promote root growth and improve quality. It overcomes the shortcomings of the existing technologies and can effectively solve the problems of short taproots, excessive lateral roots, and poor appearance in the traditional management and cultivation techniques of Isatis indigotica.

[0007] The technical solution of this invention is achieved through the following measures: a cultivation method for Isatis indigotica with directional water and fertilizer application to promote root growth and improve quality, carried out according to the following method: S1, Site selection and land preparation: Select planting sites, deep plow the planting sites in autumn, and harrow and ridge them in the following spring; S2, Sowing Management: When the soil temperature is between 10℃ and 15℃, sow the Isatis indigotica seeds in holes, cover with soil and lightly press down to ensure uniform emergence. S3, Seedling stage: Irrigate the planting area within 30 days after sowing. Irrigation management includes the first, second and third irrigations in sequence. The first irrigation is done by shallow drip irrigation after sowing. The second irrigation is done by permeable irrigation from the 5th to the 7th day after sowing. The third irrigation is done by permeable irrigation from the 20th to the 30th day. S4, taproot elongation period: Water and fertilizer management should be carried out on the planting site from day 31 to day 70. S5, taproot enlargement period: Two rounds of water and fertilizer management should be carried out on the planting site between day 71 and day 110. S6, Maturity period: From day 111 to harvest, water management is carried out on the planting site to keep the soil moisture content at 40% to 50%; S7, Field Management: Weeding and pest and disease control are carried out by shallow hoeing throughout the seedling stage, taproot elongation stage, taproot swelling stage and maturity stage. S8, Harvesting: Harvest after the growing season.

[0008] The following are further optimizations and / or improvements to the above-mentioned technical solution: In step S1 above, the planting site is selected as sandy loam or brown calcareous soil with a soil layer thickness of ≥40cm, a salt content of ≤0.3%, an organic matter content of ≥1.2%, and loose and breathable.

[0009] In step S1 above, the deep plowing depth is 50cm to 60cm, and the ridge height is 18cm to 22cm.

[0010] In step S2 above, when sowing in holes, the row spacing is set to 20cm to 25cm and the sowing depth is 0.5cm to 1.5cm.

[0011] In step S3 above, when shallow drip irrigation is used, the irrigation time is 4.0h to 4.5h and the soil depth is 20cm to 30cm; when permeable irrigation is used, the irrigation time is 8h to 10h and the soil depth is 45cm to 50cm.

[0012] In step S4 above, one water and fertilizer management includes drip irrigation of the planting area every 15 to 20 days to make the soil moisture content 55% to 60%, and applying phosphorus and potassium fertilizer and humic acid-containing fertilizer with the irrigation.

[0013] In step S4 above, the application rate of phosphorus and potassium fertilizer is 1.5 kg / mu to 2.0 kg / mu, and the phosphorus and potassium fertilizer is potassium dihydrogen phosphate. The application rate of humic acid fertilizer is 0.4 kg / mu to 0.6 kg / mu, and the humic acid fertilizer is humic acid water-soluble fertilizer.

[0014] In step S5 above, secondary water and fertilizer management includes drip irrigation of the planting area every 15 to 20 days to achieve a soil moisture content of 60% to 70%, and application of a balanced water-soluble fertilizer with a nitrogen, phosphorus and potassium ratio of 1:1:1 with the irrigation water.

[0015] In step S5 above, the application rate of balanced water-soluble fertilizer is 2.0 kg / mu to 3.0 kg / mu.

[0016] In step S8 above, the growth period is 140 to 180 days, and the plant is harvested after the first cotyledon of the plant naturally turns yellow.

[0017] This invention establishes a combined process of "water control to suppress tendrils, high phosphorus to promote growth, micronutrients to strengthen roots, and drought environment to improve quality" during the growth period of Isatis indigotica. This results in Isatis indigotica main roots that are straight, compact, and have good uniformity in thickness, with a main root length of 38cm to 45cm, fewer lateral roots, a low rate of deformed roots, a high yield of first-grade products, and a higher content of the active ingredient cypermethrin in Isatis indigotica than in conventional cultivation. This invention effectively solves the problems of short main roots, many branched and bent lateral roots, and poor appearance that exist in conventional Isatis indigotica cultivation. Attached Figure Description

[0018] Figure 1 This is a diagram of the seedling shape of Isatis indigotica after the seedling stage in Example 11 of the present invention.

[0019] Figure 2 This is a root system diagram of Isatis indigotica after harvesting in Example 11 of the present invention.

[0020] Figure 3 This is a root system diagram of Isatis indigotica root after harvesting, as shown in Comparative Example 1 of the present invention. Detailed Implementation

[0021] This invention is not limited to the following embodiments, and specific implementation methods can be determined according to the technical solutions and actual conditions of this invention. Unless otherwise specified, all chemical reagents and chemicals mentioned in this invention are well-known and commonly used chemical reagents and chemicals in the prior art; unless otherwise specified, all percentages in this invention are mass percentages; unless otherwise specified, all solutions in this invention are aqueous solutions with water as the solvent, for example, hydrochloric acid solution is an aqueous solution of hydrochloric acid; room temperature in this invention generally refers to a temperature between 15°C and 25°C, generally defined as 25°C.

[0022] The present invention will be further described below with reference to embodiments: Example 1: The cultivation method for this Isatis indigotica root directional water and fertilizer shaping and quality improvement is carried out as follows: S1, Site selection and land preparation: Select planting sites, deep plow the planting sites in autumn, and harrow and ridge them in the following spring; S2, Sowing Management: When the soil temperature is between 10℃ and 15℃, sow the Isatis indigotica seeds in holes, cover with soil and lightly press down to ensure uniform emergence. S3, Seedling stage: Irrigate the planting area within 30 days after sowing. Irrigation management includes the first, second and third irrigations in sequence. The first irrigation is done by shallow drip irrigation after sowing. The second irrigation is done by permeable irrigation from the 5th to the 7th day after sowing. The third irrigation is done by permeable irrigation from the 20th to the 30th day. S4, taproot elongation period: Water and fertilizer management should be carried out on the planting site from day 31 to day 70. S5, taproot enlargement period: Two rounds of water and fertilizer management should be carried out on the planting site between day 71 and day 110. S6, Maturity period: From day 111 to harvest, water management is carried out on the planting site to keep the soil moisture content at 40% to 50%; S7, Field Management: Weeding and pest and disease control are carried out by shallow hoeing throughout the seedling stage, taproot elongation stage, taproot swelling stage and maturity stage. S8, Harvesting: Harvest after the growing season.

[0023] Example 2: As an optimization of the above example, in step S1, the planting site is selected as sandy loam or brown calcareous soil with a soil layer thickness of ≥40cm, salt content ≤0.3% and organic matter ≥1.2%, and loose and breathable.

[0024] Example 3: As an optimization of the above example, in step S1, the deep plowing depth is 50cm to 60cm and the ridge height is 18cm to 22cm.

[0025] Example 4: As an optimization of the above example, in step S2, when sowing in holes, the row spacing is set to 20cm to 25cm and the sowing depth is 0.5cm to 1.5cm.

[0026] Example 5: As an optimization of the above example, in step S3, when shallow drip irrigation is used, the irrigation time is 4.0h to 4.5h and the soil depth is 20cm to 30cm; when permeable irrigation is used, the irrigation time is 8h to 10h and the soil depth is 45cm to 50cm.

[0027] Example 6: As an optimization of the above example, in step S4, the water and fertilizer management includes drip irrigation of the planting area every 15 to 20 days to make the soil moisture content 55% to 60%, and applying phosphorus and potassium fertilizer and humic acid-containing fertilizer with the irrigation.

[0028] Example 7: As an optimization of the above example, in step S4, the application rate of phosphorus and potassium fertilizer is 1.5 kg / mu to 2.0 kg / mu, the phosphorus and potassium fertilizer is potassium dihydrogen phosphate, and the application rate of humic acid fertilizer is 0.4 kg / mu to 0.6 kg / mu, the humic acid fertilizer is humic acid water-soluble fertilizer.

[0029] Example 8: As an optimization of the above example, in step S5, the secondary water and fertilizer management includes drip irrigation of the planting area every 15 to 20 days to make the soil moisture content 60% to 70%, and applying a balanced water-soluble fertilizer with a nitrogen, phosphorus and potassium ratio of 1:1:1 with the irrigation water.

[0030] Example 9: As an optimization of the above example, in step S5, the application rate of the balanced water-soluble fertilizer is 2.0 kg / mu to 3.0 kg / mu.

[0031] Example 10: As an optimization of the above example, in step S8, the growth period is 140 to 180 days, and the plant is harvested after the first cotyledon of the plant naturally withers and turns yellow.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows: First, in this invention, the seedling stage adopts a "three-water" irrigation method. The first and second waters follow up to protect the seedlings, which can effectively promote the germination and uniform emergence of Isatis indigotica seeds. The third water controls water and suppresses seedling growth. Appropriate alternation of dry and wet conditions can stimulate and induce the roots to explore deeper, promote the elongation and downward growth of the taproot, inhibit the growth of fibrous roots on the ground, stimulate the taproot to penetrate into the deeper soil, establish the growth advantage of a single taproot, and significantly reduce the probability of branching in the later stage. Secondly, in this invention, a single water and fertilizer management process is employed during the main root elongation period to ensure a relative soil moisture content of 55% to 60%. Phosphorus and potassium fertilizers, along with humic acid-containing fertilizers, are applied, allowing for precise water and fertilizer regulation. This period is crucial for the transition of Isatis indigotica roots from the seedling stage to the enlargement stage. By applying a combination of potassium dihydrogen phosphate and humic acid water-soluble fertilizer, phosphorus and potassium promote carbohydrate synthesis and transport, while humic acid improves soil aggregate structure and stimulates root growth. This ensures healthy growth of the above-ground stems and leaves while guiding the main root to grow longitudinally. This targeted water and fertilizer intervention promotes deep root development, laying the foundation for subsequent lateral thickening of the rhizome. Third, in this invention, by performing secondary water and fertilizer management during the main root swelling period, the root system enters the main root swelling period and requires a large amount of fertilizer. By applying a balanced nitrogen, phosphorus and potassium water-soluble fertilizer, the rigid demand of the root and stem swelling for macronutrients is precisely met, promoting the rapid accumulation of effective components, effectively promoting the uniform swelling of the main root, reducing deformed roots and hollow roots, and improving the fullness and uniformity of the roots. Fourth, in this invention, controlling the soil moisture content during the maturity period can improve the quality and increase the yield of Isatis indigotica. It can effectively control and avoid the problem of poor quality of medicinal materials caused by excessive water. At this stage, topdressing is stopped and a moderately dry environment is created to force the plant to transition from vegetative growth to reproductive growth, promote the maximum transfer of dry matter from the above-ground parts to the roots, promote the enrichment of secondary metabolites, and significantly increase the content of the active ingredient, Gloydius. Therefore, the Isatis root main root obtained by the cultivation method of Isatis root water and fertilizer directional root shaping and quality improvement of the present invention is straight, compact and uniform in thickness, with long main root length, low rate of branched and deformed roots, and high yield of first-grade product.

[0033] Example 11: The cultivation method for this Isatis indigotica root, which involves targeted water and fertilizer application to promote root development and improve quality, is as follows: S1. Site selection and land preparation: Select the planting experimental base in Huangong Village, Manas County (soil layer thickness ≥40cm, salt content ≤0.3% and organic matter ≥1.2%, loose and breathable sandy loam) as the planting site. Deeply plow the planting site in autumn (October) to a depth of 55cm. In the following spring (April), harrow and ridge the site to a height of 22cm. S2, Sowing Management: In early April (April 10), when the soil temperature is between 10℃ and 15℃, sow the Isatis indigotica seeds in holes with a row spacing of 20cm to 25cm and a sowing depth of 0.5cm to 1.5cm. After sowing, cover with soil and lightly compact to ensure uniform emergence. S3, Seedling Stage: After sowing, irrigate the planting area for the first time using a shallow drip irrigation method for 4.0 to 4.5 hours, with a soil saturation depth of 25 cm. On the 7th day after sowing, irrigate the planting area for the second time using a permeable irrigation method for 8 to 10 hours, with a soil saturation depth of 45 cm. On the 25th day after sowing, irrigate the planting area for the third time using a permeable irrigation method for 8 to 10 hours, with a soil saturation depth of 45 cm. S4, Main root elongation period: Water and fertilizer management should be carried out on the planting site from day 31 to day 70. During this period, drip irrigation should be carried out on the planting site every 20 days to make the soil moisture content 55%. Apply 1.5 kg of phosphorus and potassium fertilizer (potassium dihydrogen phosphate) and 0.5 kg of humic acid fertilizer (humic acid water-soluble fertilizer) per acre each time with irrigation. S5, main root enlargement period: During the period from the 71st to the 110th day, the planting area should be managed with water and fertilizer twice. During this period, the planting area should be drip-irrigated once every 20 days to make the soil moisture content 65%. Apply 2.5 kg of balanced water-soluble fertilizer (balanced water-soluble fertilizer 15-15-15) with a nitrogen, phosphorus and potassium ratio of 1:1:1 per mu each time with the irrigation. S6, Maturity period: From day 111 to harvest, water management is carried out on the planting site to keep the soil moisture content at 40% to 50%; S7, Field Management: Throughout the seedling stage, taproot elongation stage, taproot swelling stage and maturity stage, shallow hoeing is used for weeding to avoid damaging the roots. Physical control and biological agents are used to control pests and diseases to ensure that the plant meets the GAP green planting standards for Chinese medicinal herbs. S8, Harvesting: The entire growth period is 180 days. Harvest after the first cotyledon of the plant naturally withers and turns yellow. At this time, the root system is established and the accumulation of effective ingredients is at its highest.

[0034] In Embodiment 11 of this invention, at the planting experimental base in Huanggong Village, Manas County, step S3, after the seedling stage, shows the seedling morphology of Isatis indigotica as follows. Figure 1 As shown, from Figure 1It can be seen that after about 30 days, the roots of the Isatis indigotica seedlings are about 30cm long, and the leaves show signs of drought and are slightly white. Step S8, after harvesting, the root system diagram of Isatis indigotica is as follows. Figure 2 As shown, from Figure 2 It can be seen that the root length is on average 45cm, with 1 to 3 lateral roots, which is few. The average weight of a single plant is about 100g, and the yield is 396kg per mu. Liquid chromatography detection shows that the content of the active ingredient Gao Yichun in Isatis root is more than 2 times higher than that in the pharmacopoeia.

[0035] Example 12: The cultivation method for this Isatis indigotica root, which involves targeted water and fertilizer application to promote root development and improve quality, is as follows: S1. Site selection and land preparation: Select the planting experimental base in Huangong Village, Manas County (soil layer thickness ≥40cm, salt content ≤0.3% and organic matter ≥1.2%, loose and breathable sandy loam) as the planting site. Deeply plow the planting site in autumn (October) to a depth of 55cm. In the following spring (April), harrow and ridge the site to a height of 22cm. S2, Sowing Management: In early April (April 10), when the soil temperature is between 10℃ and 15℃, sow the Isatis indigotica seeds in holes with a row spacing of 20cm to 25cm and a sowing depth of 0.5cm to 1.5cm. After sowing, cover with soil and lightly compact to ensure uniform emergence. S3, Seedling Stage: After sowing, irrigate the planting area for the first time using a shallow drip irrigation method for 4.0 to 4.5 hours, with a soil saturation depth of 25 cm. On the 5th day after sowing, irrigate the planting area for the second time using a permeable irrigation method for 8 to 10 hours, with a soil saturation depth of 45 cm. On the 20th day after sowing, irrigate the planting area for the third time using a permeable irrigation method for 8 to 10 hours, with a soil saturation depth of 45 cm. S4, Main root elongation period: Water and fertilizer management should be carried out on the planting site from day 31 to day 70. During this period, drip irrigation should be carried out on the planting site every 20 days to make the soil moisture content 55%. Apply 1.5 kg of phosphorus and potassium fertilizer (potassium dihydrogen phosphate) and 0.5 kg of humic acid fertilizer (humic acid water-soluble fertilizer) per acre each time with irrigation. S5, main root enlargement period: During the period from the 71st to the 110th day, the planting area should be managed with water and fertilizer twice. During this period, the planting area should be drip-irrigated once every 20 days to make the soil moisture content 65%. Apply 2.5 kg of balanced water-soluble fertilizer (balanced water-soluble fertilizer 15-15-15) with a nitrogen, phosphorus and potassium ratio of 1:1:1 per mu each time with the irrigation. S6, Maturity period: From day 111 to harvest, water management is carried out on the planting site to keep the soil moisture content at 45%; S7, Field Management: Throughout the seedling stage, taproot elongation stage, taproot swelling stage and maturity stage, shallow hoeing is used for weeding to avoid damaging the roots. Physical control and biological agents are used to control pests and diseases to ensure that the plant meets the GAP green planting standards for Chinese medicinal herbs. S8, Harvesting: The entire growth period is 180 days. Harvest after the first cotyledon of the plant naturally withers and turns yellow. At this time, the root system is established and the accumulation of effective ingredients is at its highest.

[0036] In Example 12 of this invention, after harvesting at the Huangong Village planting experimental base in Manas County, the average root length of Isatis indigotica was 43cm, with 1 to 3 lateral roots, indicating few lateral roots. The average weight of a single plant was about 120g, and the yield was 383kg per mu. Liquid chromatography analysis showed that the content of the active ingredient Gao Yichun in Isatis indigotica was more than twice that of the pharmacopoeia.

[0037] Compare with Example 1: The cultivation method of this Isatis indigotica includes the following steps: (1) Site selection, land preparation, and sowing steps are the same as in Example 11; (2) Water and fertilizer management: During the seedling stage, conventional flood irrigation is used to keep the soil moist, and "three waters" irrigation management is not carried out; During the main root elongation and swelling period, an equal amount of ordinary compound fertilizer (NPK: 15-15-15) is applied per mu; (3) Field management: Weeding and pest and disease control methods are the same as in Example 11.

[0038] The root system diagram of Isatis indigotica after harvesting in Comparative Example 1 of this invention is shown below. Figure 3 As shown, from Figure 3 It can be seen that the main root of the Isatis indigotica root after harvesting in Comparative Example 1 is shortened, with more lateral roots, and a high rate of branched and deformed roots. In Comparative Example 1 of this invention, the root length of the Isatis indigotica root after harvesting is 25cm on average, the yield is 280 jin per mu, and the average weight of a single plant is about 75g.

[0039] Based on the data from Examples 11, 12, and Comparative Example 1, it can be seen that, compared with Comparative Example 1, the cultivation method of Isatis indigotica with water and fertilizer directional root shaping and quality improvement provided by Examples 11 to 12 of the present invention has significantly better results in the straightness, compactness, and uniformity of the main root of Isatis indigotica compared with Comparative Example 1. The length of the main root is increased by 0.7 times (43cm-25cm / 25cm) to 0.8 times (45cm-25cm / 25cm), with fewer lateral roots, a lower rate of branched and deformed roots, a higher yield of first-grade products, and a significantly higher content of the effective ingredient gouyichun in Isatis indigotica compared with Comparative Example 1.

[0040] Example 13: The cultivation method for this Isatis indigotica root, which involves targeted water and fertilizer application to promote root development and improve quality, is as follows: S1. Site selection and land preparation: Select the Isatis indigotica base in Akdala Town (soil layer thickness ≥40cm, salt content ≤0.3% and organic matter ≥1.2%, loose and breathable brown calcareous soil) as the planting site. Deeply plow the planting site in autumn (October) to a depth of 50cm to 60cm. In the following spring (April), harrow and ridge the soil to a height of 22cm. S2, Sowing Management: In late April (April 25), when the soil temperature is between 10℃ and 15℃, sow the Isatis indigotica seeds in holes with a row spacing of 20cm to 25cm and a sowing depth of 0.5cm to 1.5cm. After sowing, cover with soil and lightly compact to ensure uniform emergence. S3, Seedling Stage: After sowing, irrigate the planting area for the first time using a shallow drip irrigation method for 4.0 to 4.5 hours, with a soil saturation depth of 25 cm. On the 5th day after sowing, irrigate the planting area for the second time using a permeable irrigation method for 8 to 10 hours, with a soil saturation depth of 45 cm. On the 20th day after sowing, irrigate the planting area for the third time using a permeable irrigation method for 8 to 10 hours, with a soil saturation depth of 45 cm. S4, Main root elongation period: Water and fertilizer management should be carried out on the planting site from day 31 to day 70. During this period, drip irrigation should be carried out on the planting site every 20 days to make the soil moisture content 55%. Apply 1.5 kg of phosphorus and potassium fertilizer (potassium dihydrogen phosphate) and 0.5 kg of humic acid fertilizer (humic acid water-soluble fertilizer) per acre each time with irrigation. S5, main root enlargement period: During the period from the 71st to the 110th day, the planting area should be managed with water and fertilizer twice. During this period, the planting area should be drip-irrigated once every 20 days to make the soil moisture content 65%. Apply 2.5 kg of balanced water-soluble fertilizer (balanced water-soluble fertilizer 15-15-15) with a nitrogen, phosphorus and potassium ratio of 1:1:1 per mu each time with the irrigation. S6, Maturity period: From day 111 to harvest, water management is carried out on the planting site to keep the soil moisture content at 45%; S7, Field Management: Throughout the seedling stage, taproot elongation stage, taproot swelling stage and maturity stage, shallow hoeing is used for weeding to avoid damaging the roots. Physical control and biological agents are used to control pests and diseases to ensure that the plant meets the GAP green planting standards for Chinese medicinal herbs. S8, Harvesting: The entire growth period is 150 days. Harvest after the first cotyledon of the plant naturally withers and turns yellow. At this time, the root system is established and the accumulation of effective ingredients is at its highest.

[0041] In Example 13 of this invention, after harvesting from the Isatis indigotica base in Akdala Town, the average root length of the Isatis indigotica was 38cm, with 2 to 4 lateral roots. The average weight of a single plant was about 80g, and the yield was 340kg per mu. Liquid chromatography analysis showed that the content of the active ingredient Gao Yichun in Isatis indigotica was more than twice that of the pharmacopoeia.

[0042] Compare with Example 2: The cultivation method of this Isatis indigotica includes the following steps: (1) Site selection, land preparation, and sowing steps are the same as in Example 13; (2) Water and fertilizer management: During the seedling stage, conventional flood irrigation is used to keep the soil moist, and "three waters" irrigation management is not carried out; During the main root elongation and swelling period, an equal amount of ordinary compound fertilizer (NPK: 15-15-15) is applied per mu; (3) Field management: Weeding and pest and disease control methods are the same as in Example 13.

[0043] In Comparative Example 2 of this invention, after harvesting, the average root length of Isatis indigotica was 15cm, the yield was 220 jin per mu, there were many lateral roots, and the average weight of a single plant was about 50g.

[0044] Combining the data from Example 13 and Comparative Example 2, it can be seen that, compared with Comparative Example 2, the cultivation method of Isatis indigotica root water and fertilizer directional root shaping and quality improvement provided by Example 13 of the present invention results in Isatis indigotica root with straight, compact, and uniformly thick main roots, which is significantly better than that of Comparative Example 2. The main root length is increased by 1.5 times (38cm-15cm / 15cm), with fewer lateral roots, a lower rate of branched and deformed roots, a higher yield of first-grade products, and a significantly higher content of the effective ingredient gouyichun in Isatis indigotica root than that in Comparative Example 2.

[0045] In summary, the cultivation method for Isatis indigotica with targeted water and fertilizer for root shaping and quality improvement of the present invention establishes a process that combines "water control to suppress tendrils, high phosphorus to promote growth, micronutrients to strengthen roots, and drought environment to improve quality." This results in Isatis indigotica main roots that are straight, compact, and have good uniformity in thickness, with a main root length of 38cm to 45cm, fewer lateral roots, a low rate of deformed roots, a high yield of first-grade products, and a higher content of the active ingredient cypermethrin in Isatis indigotica than in conventional cultivation. This effectively solves the problems of short main roots, numerous lateral roots, and poor appearance that exist in conventional Isatis indigotica cultivation.

[0046] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A cultivation method for Isatis indigotica using targeted water and fertilizer to promote root development and improve quality, characterized in that... Perform the following steps: S1, Site selection and land preparation: Select planting sites, deep plow the planting sites in autumn, and harrow and ridge them in the following spring; S2, Sowing Management: When the soil temperature is between 10℃ and 15℃, sow the Isatis indigotica seeds in holes, cover with soil and lightly compact after sowing. S3, Seedling stage: Irrigate the planting area within 30 days after sowing. Irrigation management includes the first, second and third irrigations in sequence. The first irrigation is done by shallow drip irrigation after sowing. The second irrigation is done by permeable irrigation from the 5th to the 7th day after sowing. The third irrigation is done by permeable irrigation from the 20th to the 30th day. S4, taproot elongation period: Water and fertilizer management should be carried out on the planting site from day 31 to day 70. S5, taproot enlargement period: Two rounds of water and fertilizer management should be carried out on the planting site between day 71 and day 110. S6, Maturity period: From day 111 to harvest, water management is carried out on the planting site to keep the soil moisture content at 40% to 50%; S7, Field Management: Weeding and pest and disease control are carried out by shallow hoeing throughout the seedling stage, taproot elongation stage, taproot swelling stage and maturity stage. S8, Harvesting: Harvest after the growing season.

2. The cultivation method for Isatis indigotica with targeted water and fertilizer for root shaping and quality improvement according to claim 1, characterized in that... In step S1, the planting site is selected as a sandy loam or brown calcareous soil with a soil layer thickness of ≥40cm, a salt content of ≤0.3%, an organic matter content of ≥1.2%, and loose and breathable.

3. The cultivation method for Isatis indigotica with targeted water and fertilizer for root shaping and quality improvement according to claim 1 or 2, characterized in that... In step S1, the deep plowing depth is 50cm to 60cm, and the ridge height is 18cm to 22cm.

4. The cultivation method for Isatis indigotica with targeted water and fertilizer for root shaping and quality improvement according to claim 1, 2, or 3, characterized in that... In step S2, when sowing in holes, the row spacing is set to 20cm to 25cm and the sowing depth is 0.5cm to 1.5cm.

5. The cultivation method for Isatis indigotica with directional water and fertilizer for root shaping and quality improvement according to any one of claims 1 to 4, characterized in that... In step S3, when using shallow drip irrigation, the irrigation time is 4.0 to 4.5 hours and the soil depth is 20 to 30 cm; when using permeable irrigation, the irrigation time is 8 to 10 hours and the soil depth is 45 to 50 cm.

6. The cultivation method for Isatis indigotica with targeted root shaping and quality improvement according to any one of claims 1 to 5, characterized in that... In step S4, water and fertilizer management includes drip irrigation of the planting area every 15 to 20 days to achieve a soil moisture content of 55% to 60%, and application of phosphorus and potassium fertilizers and humic acid-containing fertilizers with the irrigation water.

7. The cultivation method for Isatis indigotica with targeted water and fertilizer for root shaping and quality improvement according to claim 6, characterized in that... In step S4, the application rate of phosphorus and potassium fertilizer is 1.5 kg / mu to 2.0 kg / mu, and the phosphorus and potassium fertilizer is potassium dihydrogen phosphate. The application rate of humic acid fertilizer is 0.4 kg / mu to 0.6 kg / mu, and the humic acid fertilizer is humic acid water-soluble fertilizer.

8. The cultivation method for Isatis indigotica with directional water and fertilizer for root shaping and quality improvement according to any one of claims 1 to 7, characterized in that... In step S5, secondary water and fertilizer management includes drip irrigation of the planting area every 15 to 20 days to achieve a soil moisture content of 60% to 70%, and application of a balanced water-soluble fertilizer with a nitrogen, phosphorus and potassium ratio of 1:1:1 with the irrigation water.

9. The cultivation method for Isatis indigotica with targeted water and fertilizer for root shaping and quality improvement according to claim 8, characterized in that... In step S5, the application rate of balanced water-soluble fertilizer is 2.0 kg / mu to 3.0 kg / mu.

10. The cultivation method for Isatis indigotica with directional water and fertilizer for root shaping and quality improvement according to any one of claims 1 to 9, characterized in that... In step S8, the growth period is 140 to 180 days, and the plant is harvested after the first cotyledon of the plant naturally turns yellow.

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