Sweet potato seedling dual-purpose efficient planting method and application

Abstract

The invention discloses a sweet potato seedling dual-purpose efficient planting method and application, and belongs to the technical field of agricultural planting. The method comprises the steps of soil preparation and fertilization, silver gray film covering and ridging, close planting and transplanting, topdressing, staged seedling cutting, intelligent vigorous growth control, comprehensive prevention and control of plant diseases and insect pests, harvesting and the like. Through soil pretreatment optimization, precise proportioning of base fertilizer and topdressing, collaborative optimization of a growth environment through a silver gray film, air holes and a drainage groove, collaborative regulation of a growth rhythm through staged seedling cutting and intelligent vigorous growth control, and multi-dimensional comprehensive prevention and control of diseases and insect pests, synchronous high yield of root tubers and seedlings is realized. A staged seedling cutting standard and nutrient dynamic regulation and control system is established, a physical environment regulation and control scheme of silver gray film covering ridging is optimized, an intelligent vigorous growth control and comprehensive prevention and control technical system is constructed, the method has the advantages of being high in resource utilization rate, environmentally friendly, wide in adaptability, remarkable in economic benefit and the like, the yield of seedlings per mu is 20,000-30,000, the yield of tuberous roots is 2500-3000 kg, the pure profit per mu is 5000-10000 yuan, and the method is suitable for large-scale popularization and application. The method can be widely applied to the sweet potato intensive planting industry.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural planting technology, in particular to an efficient planting method considering high yield of sweet potato tubers and large-scale production of sweet potato seedlings, and application of the method in industrialized planting of sweet potato. BACKGROUND

[0002] Sweet potato (Ipomoea batatas (L.) Lam.) is an important food, economic and forage crop in the world. Its tubers are rich in starch, dietary fiber and various trace elements, and its stems and leaves contain abundant protein, vitamins and minerals, which have high edible and processing value. Traditional sweet potato planting mode has obvious limitations: first, the planting target is single, and the tuber harvest is the core, the stems and leaves are often discarded as waste or used as low-value feed, and the resource utilization rate is less than 30%; second, the supply of seedlings depends on special seedling bases, and ordinary growers cannot achieve self-sufficiency and commercial output of seedlings, increasing the cost of production links; third, in the existing technology, there is a contradiction between the growth of tubers and stems and leaves in terms of nutrients, and if the stems and leaves yield is pursued unilaterally, it will hinder the tuber enlargement, and vice versa, the stems and leaves yield is insufficient, and it is difficult to achieve simultaneous high efficiency of double products.

[0003] After searching, the existing related patent technologies have the following defects: patent CN201510681703X discloses a high-yield planting method of sweet potato, which optimizes irrigation period and fertilizer ratio to improve tuber yield, but does not involve commercial utilization of stem and leaf resources, and still has the problem of resource waste; patent CN2020101697070 proposes a water-saving technology scheme of film mulching and drip irrigation for dryland sweet potato planting, and the core goal is to improve drought resistance, without paying attention to the economic value development of sweet potato seedlings; patent CN2021105417463 discloses a water and fertilizer integrated seedling raising method of sweet potato, which is only limited to the technical optimization of seedling raising link, and does not utilize the sweet potato in seedling raising and field production, and the benefit of sweet potato is not fully improved. Under the traditional planting mode, farmers rely on single tuber income, have poor risk resistance, and stem and leaf waste can easily cause field diseases and pests.

[0004] With the growth of fresh sweet potato market demand in recent years and the prominent demand for intensive supply of sweet potato seedlings, the traditional planting mode cannot meet the development needs of modern agriculture "resource efficiency and diversified income". Therefore, it is of important practical significance to develop a planting technology that can balance the growth relationship between tubers and stems and leaves and achieve simultaneous high yield of double products, to improve the comprehensive benefit of sweet potato planting and promote industrial upgrading. SUMMARY

[0005] In view of the problems of low resource utilization rate, single income, and contradiction between tuber and stem and leaf growth in the existing sweet potato planting technology, the application provides a kind of efficient planting method of sweet potato seedling and tuber, which realizes the double goals of high-quality and high-yield of sweet potato tuber and large-scale output of sweet potato seedling by precisely regulating nutrient supply, population structure and growth rhythm in the cultivation link, and significantly improves the economic income of the grower and the land utilization efficiency.

[0006] To achieve the above object, the application adopts the following technical scheme: In a first aspect, an efficient planting method of sweet potato seedling and tuber is provided, comprising the following steps: land preparation and fertilization, silver-gray film mulching and ridging, dense planting and transplanting, topdressing, pruning, spraying to control growth, disease and pest control, and harvesting tubers in August. The land preparation and fertilization specifically includes: selecting sandy loam or loam with a soil layer thickness of ≥30 cm, applying 1-2 tons of farmyard manure with a maturity of ≥80% and 10-15 kg of diammonium phosphate per mu, and deep plowing to a depth of 20-25 cm. The silver-gray film mulching and ridging specifically includes: a ridge width of 1.1-1.4 m, a ridge height of 40-50 cm, a ridge surface of 30-40 cm, an inter-ridge distance of 20-30 cm, covering a silver-gray double-color film, reserving air vents on the film surface, and compacting the film edges after spraying herbicides. The dense planting and transplanting specifically includes: transplanting virus-free seedlings when the ground temperature stabilizes at ≥10℃ from April 1 to 15, transplanting 6,500-8,000 seedlings per mu, transplanting to a depth of 2-3 cm, and leaving 4-5 stem nodes in the soil. The pruning specifically includes: pruning when the seedlings are 25-30 cm tall from May, pruning once every 10 days, a total of 3 times, leaving 1-2 stem nodes and 2-3 axillary buds during pruning, and spraying 0.4%-0.6% potassium dihydrogen phosphate solution after pruning. The spraying to control growth specifically includes: spraying a mixture of uniconazole and potassium dihydrogen phosphate after the last pruning, and controlling the soil humidity to be 50%-60%.

[0007] As a specific embodiment of the application, the farmyard manure is at least one of chicken manure, cow dung, and pig manure, with a maturity of ≥80% and a worm egg kill rate of ≥95% after 7-10 days of fermentation at a temperature of ≥60℃.

[0008] As a specific embodiment of the application, the seedlings for dense planting and transplanting are virus-free Jishu 26, Pusu 32, or Yanshu 25, with a stem diameter of ≥0.5 cm, a seedling height of 15-20 cm, and no disease and pest spots.

[0009] As a specific embodiment of the application, the topdressing specifically includes: drip applying 8-15 kg of 30-10-10 water-soluble fertilizer and 450-550 g of phoxim emulsifiable concentrate per mu 10-15 days after transplanting.

[0010] As a specific embodiment of the present application, the cutting is a phased cutting; the amount of single cutting is not more than 30% of the total amount of seedlings, the total amount of cutting is controlled at 20000-30000 plants per mu, the cutting distance from the base is 2cm-3cm, and the cutting tool is sterilized before use.

[0011] As a specific embodiment of the present application, the spraying of the mixed solution for controlling vigorous growth is: 40-60g of 5% uniconazole wettable powder per mu, mixed with 40-60kg of 0.5% potassium dihydrogen phosphate solution.

[0012] As a specific embodiment of the present application, the vigorous growth control is intelligent vigorous growth control, which adopts a drip irrigation system combined with a soil humidity sensor to intelligently control water.

[0013] As a specific embodiment of the present application, the disease and pest control includes: more than 3 years of rotation with non-solanaceous crops, silver-gray film, black light lamp for killing pests, and spraying of phoxim and chlorantraniliprole for control.

[0014] In the second aspect, the application provides the application of the planting method in sweet potato planting, and after the application, 20000-30000 seedlings of sweet potato per mu and 2500-3000 kg of sweet potato tubers are output.

[0015] As a specific embodiment of the present application, the application is suitable for different climate zones in North China, East China, Central China and South China, and is adapted to different soil conditions by adjusting the planting time, the amount of fertilization and the number of cutting.

[0016] Through the nutrient management system of "long-acting energy supply of base fertilizer + precise supplement of topdressing", the mature organic fertilizer in the base fertilizer provides sustained nitrogen, phosphorus, potassium and trace elements, and the diammonium phosphate promotes root development; the high-nitrogen water-soluble fertilizer is selected for topdressing to meet the growth demand of stems and leaves, and the nutrient balance is realized through the leaf surface fertilizer supplement after cutting.

[0017] The principle of optimizing the group structure is: a large-ridge dense planting mode is adopted, and the density configuration is 6500-8000 plants per mu, which not only ensures sufficient photosynthetic area, but also promotes the shallow distribution of the root system through the shallow planting method, which is beneficial to nutrient absorption and rapid recovery after cutting; the silver-gray film covering not only realizes the effects of soil conservation and weed suppression, but also enhances the light of the middle and lower parts of the plant through the reflected light, thereby improving the photosynthetic efficiency.

[0018] The principle of regulating the growth rhythm is: regular cutting breaks the apical dominance of the plant, stimulates the axillary bud germination, and realizes the continuous output of stems and leaves; after the last cutting, uniconazole is used to inhibit the gibberellin synthesis, control the stem elongation, reduce the soil humidity, promote the nutrient transfer from stems and leaves to tubers, and solve the core contradiction between "stem and leaf growth" and "tuber enlargement".

[0019] Ecological control principle: Integrating agricultural, physical and chemical control measures to reduce the use of chemical pesticides by more than 30%; combining silver-gray film to repel aphids with black light to attract and kill adult insects to reduce the pest population; and precise application of pesticides to avoid the risk of pesticide residues, which meets the requirements of green agricultural development. Beneficial effects

[0020] High-efficiency dual-product output: Breaking through the traditional single-output planting model, it achieves simultaneous high yields of potato seedlings and tubers, with a seedling yield of 20,000-30,000 plants per mu and a tuber yield of 2,500-3,000 kg, increasing the overall income by 80%-120% compared to the traditional tuber-only harvesting model.

[0021] Resource utilization has been significantly improved: the previously discarded sweet potato stems and leaves have been transformed into high-value seedlings, increasing the resource utilization rate from less than 30% to over 90%, and reducing agricultural waste pollution.

[0022] Outstanding ecological benefits: The fertilization model, which uses organic fertilizer as the main component and chemical fertilizer as a supplement, combined with physical control technology, reduces the amount of chemical fertilizer used by 20% and pesticides by more than 30%, thereby reducing agricultural non-point source pollution and meeting green planting standards.

[0023] Strong risk resistance: The construction of a dual income system of "roots + seedlings" avoids the risks brought about by the market price fluctuations of a single crop, and increases the farmers' ability to resist market risks by more than 50%.

[0024] Highly operable: All cultivation parameters are clearly defined, requiring no special equipment, suitable for both mechanized and manual planting, applicable to different climate zones in North China, East China, Central China, and South China, and adaptable to different soil conditions by adjusting planting time, fertilization amount, and number of pruning.

[0025] High industrial value: The high-quality seedlings produced can be directly supplied to surrounding growers, forming an industrial chain. Detailed Implementation

[0026] A high-efficiency planting method for sweet potato seedlings and tubers includes the following steps: land preparation and fertilization → mulching with silver-gray film and ridging → dense planting → topdressing and management → cyclical pruning → spraying to control excessive growth → integrated pest and disease management → tuber harvesting. Specific technical parameters are as follows: 1. Land preparation and fertilization Select soil layers with a thickness ≥30cm, pH value 5.5-7.0, and drainage coefficient ≥1.5×10⁻ 6 Sandy loam or loam soil with a density of m / s; after the previous crop is harvested, remove the crop residues in the field and deep plow to a depth of 20cm-25cm to ensure that the topsoil layer is loose and well-aerated. Base fertilizer application standard: Apply 1-2 tons of farmyard manure with a decomposition degree of ≥80% per acre, along with 10-15 kg of diammonium phosphate (N-P2O5-K2O content ratio of 18-46-0). Mix the fertilizer evenly with the soil and then level the land. The farmyard manure mentioned must be at least one of chicken manure, cow manure, or pig manure, and must be decomposed at a high temperature of above 60℃ for more than 7 days to ensure an insect egg kill rate of ≥95% and a pathogen removal rate of ≥90%.

[0027] 2. Ridging with silver-gray film The ridging operation is carried out using a ridging machine. The ridging parameters are as follows: ridging width 1.1m-1.4m (referring to the bottom width of the ridging), ridging height 40cm-50cm, ridging surface width 30cm-40cm, ridging spacing controlled at 0.8m-1.0m, the cross-section of the ridging body is an isosceles trapezoid, and the slope ratio is 1:1.2. Immediately after ridging, cover with silver-gray two-color mulch film, with a film thickness ≥0.012mm, silver side up and black side down, the edge of the mulch film embedded in the soil to a depth ≥5cm and compacted to ensure that the mulch film is tightly attached to the ridging surface without any air pockets.

[0028] 3. Dense planting Planting time: When the soil temperature at a depth of 5cm is stable at ≥10℃ for 3 consecutive days, the suitable planting period is April 1-15. In warm southern regions, it can be done as early as late March, while in cold northern regions, it needs to be delayed until mid-April. Seedling selection: Use virus-free sweet potato seedlings, such as Jishu 26, Pushu 32 or Yanshu 25. Seedlings should have a stem diameter of ≥0.5cm, a height of 15cm-20cm, be free of disease and pest spots, and have 4-5 plump axillary buds. When cutting seedlings, retain 3-4 functional leaves at the top. Planting parameters: Use a double-row shallow planting and dense planting pattern on wide ridges, with a row spacing of 30cm-40cm and a plant spacing of 15cm-20cm, resulting in a planting density of 6500-8000 plants per acre; the planting depth is 2cm-3cm, ensuring that 4-5 stem nodes of the seedlings are in the soil; water thoroughly immediately after planting, with 150ml-200ml of water per plant; Replanting management: Conduct field inspections 3-5 days after transplanting. If missing or dead seedlings are found, replant seedlings of the same size in a timely manner. After replanting, irrigate with an additional 0.2% urea solution to ensure that the survival rate of replanted seedlings is ≥95%.

[0029] 4. Topdressing Management Ten to fifteen days after planting, when the seedlings have sprouted 2-3 new leaves, apply topdressing fertilizer using drip irrigation. Apply 10 kg / mu of 30-10-10 water-soluble fertilizer (N-P2O5-K2O content ratio of 30:10:10) and mix it with 500 g / mu of phorate emulsifiable concentrate (diluted 1000 times). Apply the fertilizer evenly to the soil through the drip irrigation system to avoid direct contact with the roots and causing burns.

[0030] 5. Cyclic pruning Conditions for initiating seedling pruning: In early May, when the sweet potato seedlings reach a height of 25cm-30cm and a stem diameter of ≥0.4cm, the first pruning should begin. Pruning cycle and frequency: Prune the seedlings once every 10 days, for a total of 3 times. The last pruning should be done no later than mid-June to avoid affecting tuber enlargement. Standard procedure for pruning seedlings: Use sterilized sharp scissors to make a horizontal cut 2-3 cm from the base of the plant, retaining 1-2 stem nodes and 2-3 plump axillary buds at the base; control the number of seedlings pruned per plant to 3-5 each time, and the total number of seedlings pruned per acre to 20,000-30,000; remove residual branches and fallen leaves from the field immediately after pruning. Post-pruning growth promotion treatment: Within 2 hours after pruning, spray the leaves with a 0.4%-0.6% potassium dihydrogen phosphate solution (50kg-60kg per acre), combined with 0.1% brassinolide emulsifiable concentrate (10ml per acre) to promote the germination of lateral buds and the regeneration of stems and leaves.

[0031] 6. Spray to control excessive growth Timing for initiating growth control: 7 days after the last pruning, when the plant's stem and vine growth rate reaches more than 5cm / day, begin growth control treatment. The ratio of growth regulator: Use 50g of 5% undiluted wettable powder per acre, mix with 50kg of 0.5% potassium dihydrogen phosphate solution, stir thoroughly and then spray on the leaves, focusing on the growing point at the top of the stem. Water management: During the period of controlling excessive growth, the relative humidity of the soil should be controlled at 50%-60%, and water should be supplemented by drip irrigation to avoid flooding; when the soil humidity is higher than 65%, dig furrows in time to drain the water and prevent the vines from growing too long.

[0032] 7. Integrated Pest and Disease Management Agricultural control: Implement a crop rotation system with non-potato crops such as corn and soybeans for more than 3 years to reduce the occurrence of soil-borne diseases such as root rot and nematode disease; promptly clean up field residues after harvest and deeply plow the soil to a depth of more than 25cm to destroy the overwintering environment of pests and diseases. Physical control: In addition to using silver-gray film to repel aphids, set up 2-3 frequency-vibration black light lamps (wavelength 365nm) per acre, turn them on at night to attract and kill pests such as beet armyworm and sweet potato hawk moth, and keep the lamps 1.2m-1.5m above the ground; Chemical control: For underground pests, apply 500g / mu of phoxim emulsifiable concentrate by drip irrigation during topdressing; for leaf-eating pests, apply 3000 times dilution of 20% chlorantraniliprole suspension by foliar spraying with an interval of ≥7 days between applications, and stop applying 15 days before harvest.

[0033] 8. Root tuber harvest Harvesting time: Early to mid-August, when the sweet potato tuber skin has reached 80% lignification and the starch content is ≥20%, harvesting should be carried out in a timely manner according to market demand; Harvesting method: Sweet potato harvesters are used to dig the tubers, with the digging depth controlled at 25cm-30cm to avoid damage to the tubers; after harvesting, the tubers are sorted manually to remove damaged, deformed, and diseased tubers, and then graded and packaged.

[0034] Example 1: Application of Yanshu 25 in Linyi, Shandong 1. Test site and soil conditions Feixian County, Linyi City, Shandong Province, has sandy loam soil with a pH of 6.2, a soil layer thickness of 40cm, and an organic matter content of 1.2%. The previous crop was corn.

[0035] 2. Planting Implementation Process (1) Land preparation and fertilization: On March 25, 2024, 2 tons of decomposed chicken manure and 12 kg of diammonium phosphate were applied per mu, and the land was leveled after deep plowing to 22 cm. (2) Ridging and mulching: Ridging was started on March 28, with a ridge width of 1.2m, a ridge height of 45cm, and a ridge surface of 35cm, and covered with 0.015mm silver-gray double-color film; (3) Planting: On April 1, plant virus-free sweet potato seedlings of type 25 with a plant spacing of 18cm and a row spacing of 35cm. Plant 7200 seedlings per mu. After planting, water thoroughly to settle the roots. (4) Topdressing: On April 16, apply 10 kg / mu of 30-10-10 water-soluble fertilizer + 500 g / mu of phoxim emulsifiable concentrate by drip application; (5) Pruning: The first pruning was carried out on May 10 (seedling height 28cm), followed by pruning on May 20 and May 30, for a total of 25,000 seedlings / mu; after each pruning, spray with 0.5% potassium dihydrogen phosphate + 0.1% brassinolide. (6) Control excessive growth: On June 6, spray 50g / mu of 5% clopidogrel + 0.5% potassium dihydrogen phosphate to control soil moisture at around 55%; (7) Pest and disease control: Set up 3 black light lamps and spray 3000 times dilution of 20% chlorantraniliprole suspension on June 10 to control leaf-eating insects; (8) Harvesting: The tubers were dug up on August 5 and sorted and graded manually.

[0036] 3. Implementation Results The yield of tubers is 2800 kg / mu, of which grade 1 tubers (250-500g) account for 65%. Calculated at a market price of 3 yuan / kg, the income from tubers is 8400 yuan / mu. 25,000 seedlings are sold at 0.3 yuan / seedling, generating an income of 7500 yuan / mu from seedlings. After deducting costs (fertilizer 1200 yuan, mulch 300 yuan, seedlings 500 yuan, labor 2000 yuan) totaling 4000 yuan, the net profit is 11900 yuan / mu, which is 164% higher than the local traditional planting model (net profit 4500 yuan / mu).

[0037] Example 2: Application of Jishu 26 in Dezhou, Shandong 1. Test site and soil conditions The soil in Qihe County, Dezhou City, Shandong Province is loam, with a pH of 6.5, a soil layer thickness of 35cm, and an organic matter content of 1.0%. The previous crop was soybean.

[0038] 2. Planting Implementation Process (1) Land preparation and fertilization: On March 30, 2024, apply 1 ton of decomposed cow manure + 10 kg of diammonium phosphate per mu and plow to a depth of 20 cm; (2) Ridging and mulching: Ridges were made on April 2nd, with a ridge width of 1.1m, a ridge height of 40cm, and a ridge surface of 30cm, and covered with 0.012mm silver-gray film; (3) Planting: On April 9, virus-free Jishu seedlings were planted with a plant spacing of 20cm and a row spacing of 30cm, with 6,700 plants planted per mu; (4) Topdressing: Drip irrigation topdressing was carried out on April 22, with the same amount as in Example 1; (5) Pruning: The first pruning was carried out on May 15 (when the seedlings were 25cm tall), followed by pruning on May 25 and June 4, for a total of 20,000 seedlings per mu; (6) Controlling excessive growth: Spray clopidogrel starting from June 11, for a total of 4 sprays, with an interval of 7 days, and control soil moisture at 50%-55%; (7) Harvest: The tubers were dug up on August 10.

[0039] 3. Implementation Results The tuber yield is 2600 kg / mu, with first-grade tubers accounting for 60%, and tuber income is 6500 yuan / mu; seedling income is 6000 yuan / mu; total cost is 4500 yuan / mu, and net profit is 8000 yuan / mu, which is 150% higher than the traditional model (net profit of 3200 yuan / mu).

[0040] Example 3: Application of Pushu 32 in Kaifeng, Henan Province 1. Test site and soil conditions The soil in Xiangfu District, Kaifeng City, Henan Province is sandy loam with a pH of 6.8, a soil layer thickness of 38 cm, and an organic matter content of 1.1%. The previous crop was wheat.

[0041] 2. Planting Implementation Process (1) Land preparation and fertilization: On March 15, 2024, apply 2 tons of decomposed pig manure + 15 kg of diammonium phosphate per mu and plow to a depth of 25 cm; (2) Ridging and mulching: Ridges were made on March 18, with a ridge width of 1.4m, a ridge height of 50cm, and a ridge surface of 40cm, and covered with silver-gray film; (3) Planting: On March 20, virus-free sweet potato seedlings of variety 32 were planted with a plant spacing of 15cm and a row spacing of 40cm, with 8,000 plants planted per mu; (4) Pruning: The first pruning was carried out on May 5, with a total of 30,000 seedlings / mu pruned. The post-pruning treatment was the same as in Example 1. (5) Harvest: The tubers were dug up on August 1.

[0042] 3. Implementation Results The tuber yield is 3000 kg / mu, with first-grade tubers accounting for 70%, and tuber income is 9000 yuan / mu; seedling income is 9000 yuan / mu; total cost is 5000 yuan / mu, and net profit is 13000 yuan / mu, which is 180% higher than the traditional model.

[0043] Precautions 1. Seedling selection: Virus-free seedlings bred by reputable institutions must be used to avoid the spread of diseases and pests caused by the use of virus-infected seedlings; 2. Fertilizer decomposition: Farmyard organic fertilizer must be fully decomposed. Undecomposed fertilizer is prone to causing root burn and may carry pests and diseases. 3. Regional adjustments: In hot and rainy southern regions, the furrow depth should be increased to 30cm to prevent waterlogging; in cold northern regions, double-layer covering with mulch film or small arched greenhouses can be used, and planting should be done 5-7 days in advance. 4. Disinfection of pruning tools: Before each pruning, the scissors must be disinfected with 75% alcohol or 5% sodium hypochlorite solution to avoid cross-infection; 5. Harvesting time: Tuber harvesting should be completed before the first frost to avoid freezing damage to the tubers and affecting their quality.

[0044] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A highly efficient planting method for both sweet potato and potato seedlings, characterized in that, Includes the following steps: Land preparation and fertilization, mulching with silver-gray film to form ridges, dense planting, topdressing, pruning, spraying to control excessive growth, pest and disease control, and harvesting tubers in August; The land preparation and fertilization specifically include: selecting sandy loam or loam soil with a soil layer thickness of ≥30cm, applying 1-2 tons of farmyard organic fertilizer with a decomposition degree of ≥80% and 10-15kg of diammonium phosphate per mu, and deep plowing to a depth of 20cm-25cm. The specific steps for covering the ridges with silver-gray film include: ridge width of 1.1m-1.4m, ridge height of 40cm-50cm, ridge surface of 30cm-40cm, ridge spacing of 20-30cm, covering with silver-gray two-color film, with ventilation holes reserved on the film surface, and compacting the edges of the film after spraying herbicide. The dense planting specifically includes: planting virus-free seedlings from April 1st to 15th when the soil temperature is stable at ≥10℃, planting 6500-8000 seedlings per acre, planting at a depth of 2cm-3cm, and retaining 4-5 stem nodes in the soil. The specific pruning process includes: starting in May, when the seedlings are 25cm-30cm tall, pruning once every 10 days, for a total of 3 prunings. When pruning, retain 1-2 stem nodes and 2-3 axillary buds at the base. After pruning, spray with a 0.4%-0.6% potassium dihydrogen phosphate solution. The specific application of the spray to control excessive growth includes: after the last pruning, spraying a mixture of clopidogrel and potassium dihydrogen phosphate to control soil moisture at 50%-60%.

2. The planting method according to claim 1, characterized in that, The farmyard organic fertilizer is at least one of chicken manure, cow manure, and pig manure, with a decomposition degree of ≥80%, fermented at a high temperature of above 60℃ for 7-10 days; and an insect egg kill rate of ≥95%.

3. The planting method according to claim 1, characterized in that, The densely planted seedlings are virus-free Jishu 26, Putuo 32 or Yanshu 25, with a stem diameter ≥0.5cm, a seedling height of 15cm-20cm, and no disease or pest spots.

4. The planting method according to claim 1, characterized in that, The topdressing specifically includes: 10-15 days after planting, applying 8-15 kg / mu of 30-10-10 type water-soluble fertilizer and 450-550 g / mu of phoxim emulsifiable concentrate.

5. The planting method according to claim 1, characterized in that, The pruning is carried out in stages; the amount of seedlings pruned in a single operation shall not exceed 30% of the total number of seedlings, and the total number of seedlings pruned shall be controlled at 20,000-30,000 plants / acre. The cut shall be 2cm-3cm away from the base, and the pruning tools shall be disinfected before use.

6. The planting method according to claim 1, characterized in that, The mixture for spraying the growth regulator is as follows: 40-60g of 5% undiluted wettable powder per acre, mixed with 40-60kg of 0.5% potassium dihydrogen phosphate solution.

7. The planting method according to claim 6, characterized in that, The aforementioned "healthy growth control" system employs a drip irrigation system combined with a soil moisture sensor for intelligent water control.

8. The planting method according to any one of claims 1-6, characterized in that, The pest and disease control measures include: crop rotation with non-potato crops for more than 3 years, using silver-gray film and black light traps to kill pests, and applying phoxim by drip application and chlorantraniliprole by spraying.

9. The application of the planting method according to any one of claims 1-8 in sweet potato cultivation, characterized in that, After application, each acre produces 20,000-30,000 sweet potato seedlings and 2,500-3,000 sweet potato tubers.

10. The application according to claim 9, characterized in that, It is suitable for different climate zones in North China, East China, Central China and South China. By adjusting the planting time, amount of fertilizer and number of pruning, it can be adapted to different soil conditions.