Angelica sinensis out-of-season single seedling raising method suitable for mechanical transplanting and application thereof

Abstract

The invention discloses a Chinese angelica out-of-season single seedling raising method suitable for mechanical transplanting and application thereof, and belongs to the field of Chinese herbal medicine seedling raising and cultivation. According to the method, a sunlight greenhouse or a gutter-connected greenhouse with the altitude being 2300 m or above and the lowest temperature being larger than or equal to 8 DEG C in winter is selected, field soil without continuous cropping obstacles is matched with fried rapeseeds, trichoderma harzianum and bacillus subtilis to prepare a special matrix, a seedling raising paper book with the single-hole diameter being 19-25 mm and the height being 12 cm is adopted, pelletized seeds are dibbled in a double-grain mode from late November to early December, and the seeds are sown in the seedling raising paper book with the single-hole diameter being 19-25 mm and the height being 12 cm. Through management of precise temperature and humidity regulation and control, foliage dressing, seedling hardening and leaf cutting and the like, standardized single seedlings are cultivated and transplanted through a transplanter. According to the method, the early bolting rate of the angelica sinensis is reduced, the seedling uniformity and the transplanting survival rate are improved, the transplanting efficiency is improved, the labor cost is reduced, the yield of the angelica sinensis can be increased, efficient utilization of out-of-season resources is achieved, and support is provided for industrial large-scale standardized development.

Description

Technical Field

[0001] This invention relates to the field of agricultural planting technology, and more specifically to a method for off-season single-sowing of Angelica sinensis suitable for mechanical transplanting and its application. Background Technology

[0002] With the increasing demand for large-scale and standardized development of the Chinese medicinal materials industry, the technical bottlenecks in the traditional cultivation model of Angelica sinensis are becoming increasingly prominent. In particular, the backward state of the seedling stage has become a key factor restricting the high-quality development of the industry.

[0003] Currently, Angelica sinensis seedling cultivation mainly follows the traditional model of "sowing at the summer solstice, digging up seedlings at the cold dew, storing in cellars during winter, and transplanting the following spring." This model has three major drawbacks: First, the early bolting rate remains high. As a typical low-temperature vernalization crop, Angelica sinensis is prone to loss of control during traditional seedling cultivation due to the difficulty in regulating the natural environment. This results in an early bolting rate that is generally as high as 30%-50%, and even exceeds 50% in some production areas. After bolting, the fleshy roots of Angelica sinensis become severely lignified, significantly reducing their medicinal value and directly causing a double loss in yield and economic benefits. Second, it has poor adaptability to mechanized transplanting. Traditional seedling cultivation often uses broadcasting, resulting in dense seedling growth and intertwined root systems, forming clustered seedling clumps. This cannot meet the requirements of mechanized transplanting for seedling independence and uniformity, leading to continued reliance on manual operation in the transplanting process. This not only results in high labor intensity and low efficiency, but also in uneven transplanting density and inconsistent planting depth, affecting the uniformity of subsequent field growth and yield stability. Third, it is significantly constrained by seasons and natural conditions. Traditional seedling cultivation relies entirely on natural climate, with concentrated sowing periods and long seedling cycles. It is also susceptible to environmental factors such as low temperatures, drought, and pests and diseases, resulting in inconsistent seedling quality and large fluctuations in survival rates. This makes it difficult to form a large-scale, intensive seedling supply system. At the same time, the resources of "winter fallow fields" are not effectively utilized, and land output efficiency is low.

[0004] To address these issues, the industry has explored some technologies, such as greenhouse seedling cultivation and plug seedling cultivation. However, existing technologies still have significant shortcomings: Firstly, while some off-season seedling cultivation techniques can regulate the growth environment to some extent, they have not formed a standardized single-species seedling system. Seedling morphology is difficult to adapt to existing transplanting machinery, resulting in low integration of agricultural machinery and agronomy. Secondly, existing facility seedling cultivation mostly uses ordinary seedling containers, which are not optimized for the root growth characteristics of Angelica sinensis and lack key technologies such as temperature and humidity control and substrate ratio to support off-season seedling cultivation. This leads to poor seedling resistance, difficulty in guaranteeing transplant survival rates, and failure to fundamentally solve the problem of early bolting. In addition, most rhizome medicinal herb planting machinery is modified from crop machinery, resulting in problems such as large overall size, poor versatility, and poor integration with Angelica sinensis planting agronomy, further exacerbating the difficulty of mechanized transplanting.

[0005] Therefore, developing an off-season seedling cultivation method that can effectively regulate the vernalization process of Angelica sinensis, reduce the early bolting rate, and simultaneously achieve individualized and standardized seedling cultivation that meets the needs of mechanized transplanting is of great significance for breaking through the bottlenecks in the development of the Angelica sinensis industry, improving the scale of the industry and its comprehensive economic benefits, and is also an urgent need for the transformation and upgrading of the current Angelica sinensis planting industry. Summary of the Invention

[0006] In view of this, the present invention provides a method for off-season single-species seedling cultivation of Angelica sinensis suitable for mechanical transplanting and its application. It aims to overcome the defects of existing Angelica sinensis seedling cultivation technology, such as high bolting rate, poor mechanization adaptability, and significant seasonal constraints. It provides an off-season seedling cultivation method that can accurately control the growth environment of Angelica sinensis, achieve standardized single-species cultivation, and is adapted to mechanized transplanting. At the same time, it clarifies the application scenarios of seedling cultivation using this method, providing technical support for the large-scale and standardized development of the Angelica sinensis industry.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: First, this invention provides a method for off-season single-sowing of Angelica sinensis suitable for mechanical transplanting, comprising the following steps: Step 1: Site Selection Choose a solar greenhouse or multi-span greenhouse with an altitude of over 2300m, far away from pollution sources, flat terrain, convenient irrigation and drainage, and convenient transportation as the seedling environment; Step Two: Seedling Preparation Facility disinfection: 7-10 days before seedling cultivation, disinfect the seedling environment and facilities using sulfur fumigation or by spraying broad-spectrum fungicides and insecticides. After 24-48 hours of sealing, ensure thorough ventilation. Sulfur fumigation or broad-spectrum disinfection can completely kill any remaining pathogens and insect eggs in the facilities, reducing the risk of seedling diseases and pests and ensuring healthy seedling growth. Seedling substrate preparation: Select garden soil that has not been planted with angelica or umbelliferous crops in the past 3 years to avoid continuous cropping obstacles; crush the garden soil and pass it through a 2-3mm sieve to remove impurities and large particles to ensure that the substrate is loose; Add 1.5% to 2.0% of roasted and crushed rapeseed by weight of soil. The rapeseed is prepared by roasting it in a clean wok over low heat until it is evenly darkened in color, releases aroma, and becomes crispy, ensuring that it is fully cooked inside. After cooling, crush it into particles with a diameter of 1 to 2 mm. After roasting and crushing, rapeseed is a high-quality slow-release organic fertilizer that provides nitrogen, phosphorus, potassium and various trace elements. It can also decompose and improve the soil aggregate structure. Some substances produced during its decomposition process may have an inhibitory effect on pathogens. Then add Trichoderma harzianum and Bacillus subtilis, wherein the effective viable count of Trichoderma harzianum is ≥2×10⁻⁶. 8 CFU / g, effective viable count of Bacillus subtilis ≥1×10¹0 The dosage of CFU / g, based on soil volume, is 0.2 kg / m³ to 0.25 kg / m³. It introduces beneficial microorganisms such as Trichoderma harzianum and Bacillus subtilis. Through competition, antagonism, and parasitism, it effectively inhibits pathogens in the soil that cause root rot and damping-off, while secreting growth-promoting substances to improve the rhizosphere microecology. After thoroughly mixing the above raw materials, adjust the moisture content to 50%~60% (it should clump together when squeezed in the hand but crumble when dropped). Then cover it with a film and pile it up at 20-25℃ for 3-7 days to promote the reproduction of the microbial agent. Step 3: Selecting Seedling Booklets Select seedling paper books with a single hole diameter of 19-25mm, a height of 12cm, and a degradation period of 3-5 months. The paper books should be able to be unfolded flat, with strong adhesion between the paper tubes, good water resistance, and should not be damaged or softened during the seedling period. Step 4: Seed Selection Angelica sinensis seeds are selected, with a seed purity of ≥98%, germination rate of ≥70%, and single seed rate of ≥98%. Step 5: Assemble the tray and make the bed Filling the trays: Fill each hole of the seedling tray with the prepared seedling substrate, and compact it with a soil compactor to make the substrate full. Fill the substrate to a depth of 0.3cm to 0.5cm from the top edge of the paper tube. Seedbed preparation: Prepare seedbeds 1.2m-1.5m wide in a sterilized environment. Ensure the substrate is well-drained, maintaining a porosity of 35%-40% and a bulk density of 1.5-1.8g / cm³. 3 Arrange the seedling trays filled with substrate tightly on the seedbed, ensuring the bottom of the trays is in full contact with the ground. Lay a layer of horticultural ground cover under the seedbed. Step Six: Sowing Sowing is carried out from late November to early December, a period of off-season seedling cultivation that avoids the concentrated spring sowing season. Simultaneously, through greenhouse regulation, seedlings complete their growth during winter and can be transplanted in spring, effectively utilizing the "winter fallow" period. Single-seed sowing is used, with 2-3 pelleted seeds sown per hole to ensure high germination rates. After sowing, cover with 0.3-0.5 cm of fine soil (passed through a 10-mesh sieve) with a moisture content of 35%-40% to prevent seed exposure or excessive soil covering from affecting germination. After covering with soil, thoroughly water the substrate inside the individual seedling trays and cover with a layer of non-woven fabric or mulch to retain heat and moisture. Remove the covering when the germination rate reaches 60%-70%. Step 7: Temperature, water, and fertilizer management during the seedling stage Temperature control: From sowing to emergence, control the temperature at 18℃~28℃ during the day and 10℃~15℃ at night; from emergence to hardening off, control the temperature at 15℃~25℃ during the day and 8℃~15℃ at night. Moisture management: When the substrate surface turns white and dry, spray water on a sunny morning. Keep the water temperature between 12-18℃, avoid sudden temperature changes, keep the substrate moist, and avoid both excessive dryness and excessive wetness. When the seedlings have grown to 3-4 true leaves, choose a sunny afternoon and water them with a 0.5%-1.0% urea solution by spraying to thoroughly saturate the seedbed. When the seedlings have grown to 4-5 true leaves, spray the leaves twice with a 0.3% potassium dihydrogen phosphate solution on a sunny afternoon, with an interval of 7-10 days between the two applications. Step 8: Hardening off seedlings and pruning leaves Hardening off the seedlings should begin 15 days before the planned transplanting. Step 1: 10-15 days before transplanting, fully open the greenhouse vents during the day and close them at night to harden off the seedlings; Step 2: Open the greenhouse vents at both the top and bottom during the day and night for 5-10 days before transplanting; Step 3: Remove the greenhouse film 4 days before transplanting to allow the seedlings to fully adapt to the external environment; On the 5th to 7th day after the seedling hardening begins, prune the leaves by using sterile scissors to cut off 1 / 3 of the top leaves of the entire plant. After pruning, spray with 800 to 1000 times diluted 75% chlorothalonil wettable powder, using 30 kg of chlorothalonil solution per acre to reduce water evaporation from the leaves during transplanting. Step Nine: Seedlings Removed from Nursery When the seedlings reach the standards for leaving the nursery, they should be dug up and transplanted. The standards for leaving the nursery are: seedling age 150-180 days, plant height 10-12cm, stem diameter ≥2.0mm, with 5-6 true leaves, dark green and thick leaves, well-developed root system filling the paper tube, firm and cylindrical root ball, not falling apart, and free from quarantine pests and diseases. Water thoroughly once a day before transplanting. When digging up the seedlings, separate the individual seedlings from the paper tube, keeping the root ball of the individual seedlings intact and avoiding root damage. Step 10: Packaging and Transportation The separated individual seedlings should be placed neatly and upright in the seedling turnover basket. During transportation, they should be protected from sun exposure, rain, and wind to avoid dehydration and mechanical damage. Transplanting should be completed within 48 hours of seedling removal to ensure seedling viability and improve transplant survival rate. Furthermore, this invention also protects the off-season Angelica sinensis seedlings suitable for mechanical transplanting obtained by the above method, as well as the application of these seedlings in transplanting machines. These seedlings have regular root balls and strong independence, which can be precisely adapted to the seedling picking and planting mechanism of the transplanting machine to achieve mechanized and efficient transplanting.

[0008] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a solution with the following beneficial effects: This invention achieves the following significant technical effects through scientific site selection, precise environmental control, standardized cultivation processes, and supporting management measures: To achieve standardized individual seedlings and adapt them to mechanized transplanting: Single-hole seedling trays are used for cultivation, allowing the seedling roots to grow independently and form compact cylindrical root balls. This greatly improves the uniformity of indicators such as plant height, stem diameter, and number of leaves, fully meeting the requirements of mechanized transplanting for seedling morphology. No manual seedling separation is required during transplanting. The transplanting machine picks up seedlings smoothly and plants them at a consistent depth, which improves transplanting efficiency, reduces labor costs, and ensures uniform transplanting density, thus improving the uniformity of growth in the field. Off-season cultivation can also improve resource utilization, break the traditional seasonal restrictions of "sowing in spring and harvesting in autumn", sow from late November to early December and transplant in spring, effectively utilize winter greenhouse resources and "winter fallow fields", achieve staggered supply of seedlings, and solve the problem of supply and demand imbalance of traditional seedling cultivation; the seedling cycle is 150 days to 180 days and is not affected by environmental factors such as natural drought and low temperature, and the survival rate of seedlings is steadily improved. With specialized substrate formulation and meticulous management, the seedlings have well-developed root systems, thick stems, and dark green, thick leaves, significantly enhancing their resistance to adverse conditions (drought and disease); the seedling recovery period after transplanting is shortened, and the later growth is vigorous, increasing the yield of Angelica sinensis fleshy roots; The seedling cultivation method of this invention has a standardized process and clear parameters. The required facilities and materials are readily available, and it can be promoted on a large scale in the main production areas of Angelica sinensis. The cultivated individual seedlings are compatible with existing Chinese medicinal herb transplanting machines, without the need for major modifications to the machinery. This achieves a deep integration of agricultural machinery and agronomy, providing key technical support for the large-scale, standardized, and intensive development of the Angelica sinensis industry, and has significant economic, social, and ecological benefits. Detailed Implementation

[0009] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0010] Experimental Example 1 (I) Research on Improving Soil Treatment Technology for Angelica Seedling Cultivation I. Experimental Design and Methods Time and location: November 2024, in the greenhouse of the project's experimental demonstration base (solar greenhouse in Luye Village, Mazichuan, Minxian County, Dingxi City, Gansu Province, at an altitude of 2500m).

[0011] Experimental materials: non-angelica previous crop field soil crushed by a soil pulverizer, honeycomb paper tubes (12cm high), and angelica pelleted seeds provided by the Institute of Chinese Medicinal Herbs of Gansu Academy of Agricultural Sciences.

[0012] Experimental treatment: There were 4 treatments, each with 3 replicates, arranged in randomized block design.

[0013] Treatment CK (control): Soil was not treated in any way.

[0014] Treatment A (chemical treatment): Disinfect the soil by spraying with an 800-fold dilution of 50% carbendazim wettable powder.

[0015] Treatment B (Biological agent treatment): Add Trichoderma harzianum agent (2×10) to the soil. 8 CFU / g) and Bacillus subtilis inoculum (10^ 10 The dosage (CFU / g) is 0.25 kg / m³.

[0016] Treatment C (Bio-inoculant + Organic matter treatment): Add 1.5% (w / w) roasted rapeseed (crushed) to the soil, and add the same amount of Trichoderma harzianum and Bacillus subtilis as in Treatment B; Observation indicators: germination rate (30 days after sowing), plant height, stem diameter (90 days after sowing), disease and pest incidence rate (statistics collected 120 days after sowing), seedling fresh weight, and dry weight. The above data were observed, recorded, and then statistically analyzed.

[0017] II. Experimental Results and Data Analysis Table 1. Effects of different soil treatments on seedling emergence and growth of Angelica sinensis.

[0018] Note: Different letters after the data in the same column indicate that the difference is significant at the P<0.05 level.

[0019] III. Results Analysis and Conclusions Emergence and growth: Treatment C (bio-inoculant + organic matter) showed significantly higher emergence rate, plant height, stem diameter, and seedling fresh weight than other treatments (P<0.05). This indicates a significant synergistic effect between the slow-release nutrients provided by roasted rapeseed and the growth-promoting effects of beneficial microorganisms, which significantly promoted robust seedling growth.

[0020] Disease control: The control group (CK) experienced severe disease outbreaks. Chemical treatment A had some effect, but biological treatments B and C were more effective, with treatment C showing the best disease control, exhibiting significantly lower incidence rates of root rot and damping-off compared to the control (P<0.01). This demonstrates the superior ability of *Trichoderma harzianum* and *Bacillus subtilis* to inhibit pathogens, and the addition of organic matter may have further promoted the colonization and reproduction of beneficial microorganisms.

[0021] Conclusion: Considering all indicators, treatment C (soil not previously treated with Angelica sinensis + 1.5% roasted rapeseed + Trichoderma harzianum & Bacillus subtilis) is the optimal soil treatment scheme, which has the effects of promoting growth, resisting disease and improving soil, and is also ecologically safe.

[0022] (II) Improvement of mechanized precision sowing technology for Angelica sinensis seeds This experiment directly introduced the mature Angelica dahurica granulated seed product from the Institute of Chinese Medicinal Herbs, Gansu Academy of Agricultural Sciences. Sowing was carried out at the demonstration base using a handheld precision seeder.

[0023] Results and Analysis: Sowing efficiency: Pelleted seeds enable precise single-seed sowing, with a sowing efficiency of up to 150-200 trays / hour / person, which is about 5-8 times more efficient than traditional manual sowing, and there is no need for thinning, which greatly saves labor.

[0024] Emergence effect: The pelleted seeds emerge uniformly, with an average emergence rate of 90.2% observed in the field, and the seedling spacing is uniform, laying the foundation for cultivating uniform "individual seedlings".

[0025] Conclusion: Using mature Angelica dahurica pelleted seeds is the preferred method to achieve precise, standardized, and mechanization-friendly seedling cultivation in Angelica dahurica facilities. The technology is mature and the results are stable.

[0026] (III) Research on the Off-Season Seedling Raising Model of Angelica sinensis in Facilities I. Experimental Design and Methods: Experimental materials: honeycomb paper tubes of different heights (8cm, 10cm, 12cm, 15cm), and soil treatment was uniformly the above-mentioned optimal scheme (treatment C).

[0027] Observation indicators: At the end of the seedling stage (before transplanting), measure plant height, stem diameter, number of leaves, taproot length, and fresh root weight, and observe the formation of the root ball. Calculate the survival rate after transplanting.

[0028] II. Experimental Results and Data Analysis Table 2. Effects of different paper tube heights on the quality and transplant survival rate of Angelica sinensis seedlings. Paper tube height (cm) Plant height (cm) Stem diameter (mm) Main root length (cm) Fresh weight of roots (g / plant) Root ball integrity Transplant survival rate (%) 8 9.8±0.6b 2.0±0.2b 7.1±0.5c 0.25±0.03c Loose, easily broken clumps 82.5±3.2c 10 10.5±0.5ab 2.1±0.1ab 9.5±0.6b 0.38±0.04b Relatively firm, slightly loose 90.1±2.5b 12 11.0±0.4a 2.2±0.1a 11.8±0.4a 0.52±0.05a Firm and well-formed 96.8±1.5a 15 10.8±0.5a 2.2±0.1a 13.5±0.5a 0.55±0.04a Firm and well-formed 95.5±1.8a III. Results Analysis and Conclusions Seedling quality: Seedlings grown in 12cm and 15cm paper tubes showed significantly better growth in plant height, stem diameter, taproot length, and root biomass than those grown in 8cm and 10cm tubes (P<0.05). This indicates that sufficient root growth space is crucial for cultivating robust seedlings.

[0029] Root ball and transplanting: Due to limited space, the root system of 8cm and 10cm paper tubes was not sufficiently coiled, making it easy for the root ball to break apart and damage the roots when removing the seedlings, resulting in a significantly lower transplant survival rate. The root balls of 12cm and 15cm paper tubes were intact and compact, and there was no significant difference in transplant survival rate (P>0.05), both exceeding 95%.

[0030] Cost and benefit considerations: While 15cm paper tubes produce good results, they result in fewer seedlings per unit area, and the costs of paper and substrate are higher. Considering the input-output ratio, 12cm paper tubes offer better economic benefits while ensuring extremely high transplant survival rates and high-quality seedlings.

[0031] Conclusion: A 12cm high honeycomb paper tube was determined to be the best choice for cultivating "Angelica sinensis seedlings", successfully achieving the unity of robust seedling cultivation and damage-free transplanting.

[0032] (iv) Research on the improvement of water and fertilizer management technology for off-season seedling cultivation of Angelica sinensis in facilities I. Experimental Design and Methods Seedling strengthening experiment: At the 4-5 true leaf stage of seedlings, different concentrations of potassium dihydrogen phosphate (0.1%, 0.3%, 0.5%) were sprayed on the leaves, with water spraying as a control. Plant height and stem diameter were investigated 7 days later.

[0033] Hardening-off experiment: Before transplanting (starting April 20th), three hardening-off treatments were set up: 7 days, 10 days, and 14 days. Under each hardening-off treatment, two sub-treatments were set up: one with leaf pruning (removing 1 / 3 of the leaf tip) and one without leaf pruning. The survival rate on the 7th day after transplanting and the greening-up rate (new leaves growing) on ​​the 15th day were observed.

[0034] II. Experimental Results and Data Analysis Table 3: Effects of different hardening treatments on the survival and regreening of Angelica seedlings after transplanting

[0035] Table 4: Effects of potassium dihydrogen phosphate spraying on the growth of Angelica sinensis seedlings

[0036] III. Results Analysis and Conclusions Measures to promote strong seedling growth: Spraying with 0.3% and 0.5% potassium dihydrogen phosphate can significantly thicken the stems (P<0.05), thus promoting strong seedling growth. However, the 0.5% concentration has a slight inhibitory effect on plant height. The 0.3% concentration is the best choice for achieving strong seedling growth without side effects.

[0037] Hardening off seedlings and leaf pruning: The duration of hardening off seedlings and the methods of leaf pruning have a significant impact on transplant survival. The treatment combination of 10 days of hardening off seedlings combined with leaf pruning resulted in the highest survival rate and greening-up rate, significantly outperforming other combinations (P<0.05). 7 days of hardening off seedlings was insufficient, and while 14 days of hardening off seedlings also yielded good results, it prolonged the seedling period. Leaf pruning effectively reduces leaf transpiration and balances root absorption, making it a key measure to promote rapid greening-up.

[0038] Conclusion: A water, fertilizer and plant type management technique was developed, with the core of "spraying 0.3% potassium dihydrogen phosphate once at the 4-5 leaf stage, gradually hardening off the seedlings for 10-14 days before transplanting, and pruning 1 / 3 of the leaves in the middle of the hardening-off period".

[0039] Example 1 The optimal technical parameters and operating procedures obtained from the above experimental example 1 (soil treatment C, pelleted seeds, 12cm paper tubes, 0.3% potassium dihydrogen phosphate for seedling strengthening, 10-14 days of hardening off and leaf pruning) are systematically integrated and assembled to form a standardized and replicable "Angelica off-season seedling cultivation technology model". Through the establishment of a large-scale core demonstration area and a multi-point experimental network, the model is verified and demonstrated on a large scale in representative townships of different ecological regions in Dangchang County, and the stability, adaptability and promotion value of the technology system are comprehensively evaluated.

[0040] I. Demonstration Zone Layout and Base Construction: The core demonstration area was selected in Muer Town, Dangchang County. This town is a traditional medicinal herb planting area in Dangchang County, and its altitude, climate, and soil conditions are representative. Through cooperation with local cooperatives, a core demonstration area of ​​52 mu (approximately 3.8 hectares) was constructed in a concentrated and contiguous manner. All demonstration plots underwent land preparation, application of base fertilizer (mainly well-rotted farmyard manure, supplemented with an appropriate amount of compound fertilizer), ridging, and mulching according to unified requirements before transplanting.

[0041] Multi-site experimental network: To test the adaptability of the technology to different microclimates and soil conditions, the project also set up auxiliary experimental sites in three townships: Bali Town, Awu Town, and Pangjia Township. At each site, 3-5 representative cooperatives or large-scale growers were selected, and experimental fields of 5-10 mu (approximately 0.33-0.67 hectares) were established according to unified technical procedures, forming a multi-site verification network.

[0042] II. Analysis of the Implementation Process and Results in the Core Demonstration Area (Muer Town) Seedling Transportation and Transplanting: In late May 2025, the "Angelica sinensis seedlings" cultivated by the project reached the standards for leaving the nursery. To ensure the survival rate of transplanted seedlings, strict seedling protection transportation measures were taken: individual seedlings were packed in turnover baskets, layered and loaded onto vehicles to avoid crushing, and covered with tarpaulins to prevent sun exposure and water loss. After being transported to the demonstration base in Muer Town, personnel were immediately organized to transplant them.

[0043] Transplanting period: May 28 to June 10, 2025.

[0044] Transplanting Method: The demonstration area highlighted the advantages of mechanization. Approximately 2 mu (about 0.33 hectares) were transplanted using small, self-propelled semi-automatic transplanters, while the remaining 50 mu (about 3.3 hectares) were transplanted manually by trained farmers as a control. During mechanical transplanting, individual seedlings were gently pushed out of paper tubes and precisely planted into the mulched ridges by the transplanter, ensuring uniform depth and regular spacing between plants and rows.

[0045] Transplanting density: uniformly 25cm between plants and 30cm between rows, high-ridge cultivation, ridge width 1m, 4 rows per ridge.

[0046] Field management and data recording: After transplanting, regularly record agricultural operations and weather conditions.

[0047] Water management: Water immediately after transplanting to help the roots establish, and then replenish water as needed according to soil moisture to ensure successful greening.

[0048] Pest and disease monitoring: Regular inspections revealed no large-scale outbreaks of pests and diseases.

[0049] Data Survey: On the 7th, 15th, and 30th days after transplanting, the project team organized technicians to conduct a systematic survey of the seedling survival, regrowth, and early growth in the demonstration area. The survey used a diagonal five-point sampling method, with 50 plants continuously surveyed at each point.

[0050] Demonstration results and data analysis: Table 5. Comprehensive Evaluation Table of Transplanting Performance in the Core Demonstration Area of ​​Muer Town (52 mu) Survey Project Investigation time Mechanical transplanting area (2 mu) Artificial transplanting area (50 mu) Overall performance Survival rate (%) 7 days after transplanting 2025.06.15-05.17 96.8±1.5 95.5±2.0 96.3±1.8 Greening rate (%) 15 days after transplanting 2025.06.22-05.24 95.2±1.8 93.8±2.2 94.8±2.0 Early bolting rate (%) 2025.08.20-08.25 4.1±0.8 4.5±1.0 4.2±0.9 Seedling uniformity (coefficient of variation) When transplanting 8.5 11.2 9.2 Transplanting efficiency (acres / person / day) During transplanting 2.5-3.0 0.5-0.8 Overall efficiency increased by approximately 4 times Results analysis: (1) Extremely high survival rate and greening rate: Whether mechanical or manual transplanting, the survival rate exceeds 95% and the greening rate exceeds 93%. This fully demonstrates the great advantage of transplanting "Angelica single seedlings" with substrate without damaging the root system, and effectively solves the core problem of long recovery period and unstable survival rate after transplanting traditional bare-root seedlings.

[0051] (2) Extremely low early bolting rate: The overall bolting rate was successfully controlled at 4.2%, far lower than the traditional seedling level of 15%~30%. This is due to the fact that the present invention effectively regulates the physiological age and growth rhythm of seedlings by controlling the sowing period, precise temperature and light management, and hardening off seedlings and pruning leaves, thus preventing them from passing through the vernalization stage too early and curbing the occurrence of early bolting from the source.

[0052] (3) Excellent seedling uniformity: The seedling uniformity (coefficient of variation 8.5%) in the mechanically transplanted area was significantly better than that in the artificially transplanted area. This is due to the highly uniform "individual seedlings" produced by pelleting precision seeding and standardized environmental management, which lays a solid foundation for subsequent field management and balanced harvest.

[0053] (4) Significant efficiency improvement: Mechanical transplanting is more than 4 times more efficient than manual transplanting, which greatly reduces labor intensity, saves labor costs, and demonstrates the huge application potential of this technology system in modern agriculture.

[0054] Verification results from multiple locations (Bali Town, Awu Town, Pangjia Township): To understand the adaptability of this technology system to a wider area, the project team conducted follow-up investigations at three auxiliary test sites.

[0055] test area Test performance Bali Town test site (slightly lower altitude, slightly higher temperature) The transplant survival rate at this site was 95.1%, and the seedlings recovered well. However, due to the rapid rise in local spring temperatures, technicians reported that the hardening-off period was slightly insufficient, resulting in minor leaf scorch in some fields, but these areas subsequently recovered well. This indicates that in similar climate zones, the hardening-off period can be appropriately advanced or extended to 14 days. The test site in Awu Town (with an altitude similar to that of Muer Town) The results at this site were closest to those in the core demonstration area, with a transplant survival rate of 96.0% and a bolting rate of 4.0%, verifying the high replicability of the technology system in similar ecological zones. Pangjia Township Experimental Site (Some fields are shaded areas) The survival rate of transplanted seedlings at this site was 94.0%, slightly lower than other sites. Analysis suggests this is related to the higher soil moisture and slower soil temperature rise in the area. It is recommended that when promoting this method in similar areas, special attention should be paid to creating high ridges and digging deep drainage ditches, and the transplanting period may need to be appropriately delayed by 3-5 days. Comprehensive conclusions from multi-site trials: The integrated technical system of this invention demonstrated broad adaptability and stability in different townships of Dangchang County. Although slight fluctuations occurred due to minor differences in microclimate and soil conditions, the core indicators (survival rate and bolting rate) were significantly superior to traditional seedling cultivation methods, proving that the technical system has a solid technical foundation for promotion throughout the county. Furthermore, the multi-site trials provided valuable first-hand data for future "fine-tuning" and optimization of the technology in different ecological zones.

[0056] The embodiments described in this specification are presented in a progressive manner. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for off-season single-sowing of Angelica sinensis suitable for mechanical transplanting, characterized in that, Includes the following steps: Step 1: Site Selection Greenhouses with an altitude of over 2300m, far from pollution sources, flat terrain, convenient irrigation and drainage, and convenient transportation were selected as the seedling cultivation environment. Step Two: Seedling Preparation (2.1) Facility disinfection: Disinfect the seedling environment and facilities 7 to 10 days before seedling cultivation; (2.2) Preparation of seedling substrate: Select garden soil that has not been planted with Angelica sinensis or Umbelliferae crops in the past 3 years. After crushing the garden soil and passing it through a 2-3 mm sieve, add 1.5%-2.0% of roasted and crushed rapeseed by weight of soil, and then add Trichoderma harzianum and Bacillus subtilis. After mixing thoroughly, adjust the moisture content to 50%-60%, then cover with a film and pile up at 20-25℃ for 3-7 days. Step 3: Selecting Seedling Booklets Select seedling paper books with a single hole diameter of 19-25mm, a height of 12cm, and a degradation period of 3-5 months; Step 4: Seed Selection Angelica sinensis seeds are selected, with a seed purity of ≥98%, germination rate of ≥70%, and single seed rate of ≥98%. Step 5: Plating and Making the Bed (5.1) Filling the trays: Fill each hole of the seedling tray with the prepared seedling substrate, and compact it with a soil compactor to make the substrate full, maintaining a porosity of 35%-40% and a bulk density of 1.5-1.8 g / cm³. 3 Fill the substrate to a depth of 0.3cm to 0.5cm from the top edge of the paper tube; (5.2) Making the seedbed: Make the seedbed in the disinfected environmental facilities, arrange the seedling trays filled with substrate tightly on the seedbed, and make full contact between the bottom of the trays and the ground. Lay a layer of horticultural ground cover under the seedbed; Step Six: Sowing From late November to early December, sow using a single-seed sowing method, sowing 2-3 pelleted seeds per hole. After sowing, cover with 0.3-0.5 cm of fine soil with a moisture content of 35%-40% that has passed through a 10-mesh sieve. After covering with soil, thoroughly water the substrate inside the seedling tray and cover with a layer of non-woven fabric or mulch. Remove the covering when the germination rate reaches 60%-70%. Step 7: Temperature, water, and fertilizer management during the seedling stage From sowing to emergence: Daytime temperature 18℃~28℃, nighttime temperature 10℃~15℃; From emergence to hardening off: Daytime temperature 15℃~25℃, nighttime temperature 8℃~15℃; When the substrate surface turns white and dry, choose a sunny morning to spray water, keeping the water temperature between 12-18℃, avoiding sudden temperature changes, and keeping the substrate moist, avoiding both excessive dryness and excessive wetness; When the seedlings have grown to 3-4 true leaves, choose a sunny afternoon and water them with a 0.5%-1.0% urea solution by spraying to thoroughly saturate the seedbed. When the seedlings have grown to 4-5 true leaves, spray the leaves twice with a 0.3% potassium dihydrogen phosphate solution on a sunny afternoon, with an interval of 7-10 days between the two applications. Step 8: Hardening off seedlings and pruning leaves Hardening off the seedlings should begin 15 days before the planned transplanting. Step 1: 10-15 days before transplanting, fully open the greenhouse vents during the day and close them at night to harden off the seedlings; Step 2: Open the greenhouse vents at both the top and bottom during the day and night for 5-10 days before transplanting; Step 3: Remove the greenhouse film 4 days before transplanting to allow the seedlings to fully adapt to the external environment; On the 5th to 7th day after the seedling hardening begins, prune the leaves by using sterile scissors to cut off 1 / 3 of the top leaves of the entire plant. After pruning, spray with 800 to 1000 times dilution of 75% chlorothalonil wettable powder, using 30 kg of chlorothalonil solution per acre. Step Nine: Seedlings Removed from Nursery After reaching the standard for leaving the nursery, the seedlings are dug up and transplanted. One day before transplanting, the seedlings are thoroughly watered. When digging up the seedlings, the individual seedlings are separated from the paper book, keeping the root ball of the individual seedlings intact. Step 10: Packaging and Transportation The separated individual seedlings are placed neatly and upright in the seedling turnover basket, and protected from sun exposure, rain and wind during transportation.

2. The method for off-season single-sowing of Angelica sinensis suitable for mechanical transplanting according to claim 1, characterized in that, The minimum indoor temperature of the solar greenhouse mentioned in step one during winter shall not be lower than 8℃.

3. The method for off-season single-sowing of Angelica sinensis suitable for mechanical transplanting according to claim 1, characterized in that, In step (2.1), disinfection is carried out by fumigation with sulfur powder or by spraying broad-spectrum bactericides and insecticides. After 24 to 48 hours of sealing, the facility is fully ventilated.

4. The method for off-season single-sowing of Angelica sinensis suitable for mechanical transplanting according to claim 1, characterized in that, The method for preparing the roasted and crushed rapeseed described in step (2.2) is as follows: Stir-fry the rapeseed in a clean wok until it is evenly darkened in color, releases its aroma, and becomes crispy, ensuring that it is fully cooked inside. After cooling, crush it into particles with a diameter of 1-2 mm.

5. A method for off-season single-sowing of Angelica sinensis suitable for mechanical transplanting according to claim 1, characterized in that, The effective viable count of Trichoderma harzianum in step (2.2) is ≥2×10⁻⁶. 8 CFU / g, effective viable count of Bacillus subtilis ≥1×10¹ 0 The dosage of CFU / g, based on soil volume, is 0.2 kg / m³ to 0.25 kg / m³.

6. A method for off-season single-sowing of Angelica sinensis suitable for mechanical transplanting according to claim 1, characterized in that, The standards for leaving the nursery in step (9.1) are: seedling age 150d~180d, plant height 10cm~12cm, stem diameter ≥2.0mm, with 5~6 true leaves, dark green and thick leaves, well-developed root system filling the paper tube, root ball tight and cylindrical, not falling apart, and free from quarantine pests and diseases.

7. A method for off-season single-sowing of Angelica sinensis suitable for mechanical transplanting according to claim 1, characterized in that, In step ten, transplanting should be completed within 48 hours of seedling removal.

8. Angelica sinensis off-season individual seedlings suitable for mechanical transplanting obtained by the method of any one of claims 1-7.

9. The application of the off-season Angelica sinensis seedlings suitable for mechanical transplanting as described in claim 8, characterized in that, It is used for transplanting with a transplanter.

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