Tobacco seedling raising method

Abstract

The invention belongs to the technical field of tobacco planting, and discloses a tobacco seedling raising method which comprises the following steps: building a seedling shed and a seedling pool, preparing a paper bowl plate filled with a substrate, sowing tobacco seeds in the substrate, performing water management, performing fertilization management, performing temperature management, performing pest control and the like, the water content of the substrate reaches 70-80%. Seedling growing personnel can conveniently control moisture supply of the matrix in the paper bowl plate, and the requirement for the horizontal plane of the pond bottom is lowered while tobacco seed development in the paper bowl plate is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of tobacco planting, and in particular to a tobacco seedling raising method. Background Art

[0002] At present, there are two main methods for tobacco cultivation in my country: tray seedling cultivation and floating seedling cultivation. However, the tobacco seedlings cultivated by these two methods need to be loaded into the transplanter one by one when transplanting. In order to improve the transplanting efficiency, tobacco experts began to consider using foldable paper trays to cultivate tobacco seedlings, so as to achieve continuous transplanting during transplanting. However, paper trays are not naturally suitable for floating seedling cultivation, and tray seedling cultivation makes it difficult to control the moisture supply of the substrate in the paper trays.

[0003] Therefore, a tobacco seedling raising method is urgently needed to solve the above-mentioned technical problems. Summary of the invention

[0004] The object of the present invention is to provide a tobacco seedling raising method, which can keep the water content of the matrix at 70-80% suitable for the tobacco seeds to break through the soil and develop, ensure the development of the tobacco seeds in the paper pot tray and reduce the requirement for the horizontal surface of the pool bottom.

[0005] To achieve this object, the present invention adopts the following technical scheme: a tobacco seedling raising method, comprising the following steps:

[0006] 1) Build a seedling shed and a seedling pool;

[0007] 2) preparing a paper pot tray filled with a substrate, sowing tobacco seeds in the substrate and placing the paper pot tray into the seedling pool;

[0008] 3) Water management: adding water to the seedling pool to make the water content of the matrix reach 70-80% until the seedlings emerge, waiting for the water of the matrix in the paper pot tray to evaporate naturally until the water content of the matrix is ​​less than 55%, watering the seedling pool, and after the water content of the matrix reaches 70-80%, repeating the steps of waiting for the water of the matrix to evaporate naturally and then watering until the seedlings are transplanted;

[0009] 4) Fertilization management: 8-12 days after sowing, when 70-80% of the seeds have emerged, apply the first additional fertilizer with a water-soluble fertilizer specially used for tobacco seedlings. After emergence, the concentration of the water-soluble fertilizer is increased in stages according to the development stage of the tobacco seedlings. During the seedling stage, water and fertilizer management is carried out in the steps of applying water-soluble fertilizer twice and then adding water once;

[0010] 5) Temperature management: After sowing, the temperature in the greenhouse should be kept in the range of 20℃-28℃; after germination, the temperature in the greenhouse should be kept in the range of 22℃-30℃; after the big cross period, the temperature in the greenhouse should be kept in the range of 25℃-30℃;

[0011] 6) Pest and disease control.

[0012] Preferably, the watering amount M of the seedling pool satisfies: a×10.5ml×b≤M≤a×15.8ml×b, wherein a is the total number of tobacco seeds in each paper pot tray, and b is the total number of paper pot trays.

[0013] Preferably, during the water management operation, a pressurized sprinkler system is used to water the seedling pond.

[0014] Preferably, in the water management operation, drip irrigation strips or Φ2.0-2.5 cm plastic pipes are used to water the seedling pool.

[0015] Preferably, in the fertilization management operation: from the seedling stage to the big cross stage, the water-soluble fertilizer is added at a concentration of 100-150ppm; after the big cross stage, the water-soluble fertilizer is added at a concentration of 200ppm.

[0016] Preferably, when performing water and fertilizer management, 5-7 days after adding water and fertilizer, the water at the bottom of the pond dries up as the standard, and water and fertilizer management should be performed the next day after the water dries up.

[0017] Preferably, in the temperature management operation, water is applied every 2-3 days. If the temperature in the greenhouse is higher than the range that should be maintained, water is applied every 1-2 days.

[0018] Preferably, in the pest control operation, insect control is carried out once before emergence and once again after entering the small cross stage, using high-chloride emamectin benzoate insecticide, diluted and sprayed at 1500 times.

[0019] Preferably, from the small cross stage to the large cross stage, use 0.5 kg of 50% phoxim emulsifiable concentrate with 5 kg of water and mix with 50 kg of bait to lure and kill ground beetles, crickets, mole crickets and slugs.

[0020] Preferably, in the pest control operation, during the cat-stage of tobacco seedlings, oligosaccharide·morphoguanidine, oligosaccharide·chain protein, and Ningnanmycin agents are used to prevent secondary viral diseases; and Bacillus subtilis containing 100 billion Bacillus and a concentration of 5000 times is used to prevent "two black diseases".

[0021] The beneficial effects of the present invention are as follows: in the emergence stage when tobacco seeds develop from seeds to tobacco seedlings, water is applied in time, and from the emergence stage to the seedling stage when the seedlings are transplanted, the dry-wet alternating management steps of waiting for the water in the substrate to evaporate naturally and then watering are repeated, so that the moisture content of the substrate reaches 70-80% in the entire seedling stage. By adjusting the moisture content of the substrate, the water supply of the substrate in the paper pot tray is accurately controlled to ensure that the tobacco seedlings are in a dry-wet environment suitable for growth, promote seed germination and seedling growth, and promote the root development of the tobacco seedlings and enhance the stress resistance of the tobacco seedlings. In addition, water and fertilizer management is carried out under the premise of dry-wet alternating water management, which can improve the continuity and consistency of tobacco seed seedling cultivation, facilitate seedling personnel to control the water supply of the substrate in the paper pot tray, reduce the amount of water and fertilizer used in seedling cultivation, ensure the development of tobacco seeds in the paper pot tray, and the bottom level of the seedling cultivation pool does not need to be too high, thereby reducing the requirements for the bottom level of the pool. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention.

[0023] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0025] In the description of this embodiment, the terms "upper", "lower", "right", etc., are directions or positional relationships, which are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0026] A tobacco seedling raising method provided in an embodiment of the present application comprises the following steps:

[0027] 1) Build a seedling shed and a seedling pool;

[0028] In the early stage of seedling cultivation, seedling cultivation personnel need to build seedling cultivation facilities that meet the standards. The specific construction steps and facility specifications are as follows:

[0029] ① Build a seedling shed: The length of the shed is more than 40 mesh and 60 mesh, and the height is 4.2m. The shed body is equipped with two nets and two films (insect-proof net 70-80 mesh, sunshade net with a shading rate of more than 50%, pool film 100 threads, shed film 120 threads, the spacing between the sheds is 1.5m, the plastic film is fixed with a slot and a spring, and sealed with anti-aging rubber strips).

[0030] ② Construction of seedling pools: The size and number of seedling pools are set according to the area of ​​the seedling shed. In this embodiment, a single seedling pool is 31.52m long, 1.74m wide, and 0.2m high, and the shed is equipped with 16 seedling pools.

[0031] ③ Arrangement of automatic control system: Arrange pressure tank, frequency converter, main control module, temperature and humidity sensor, drive module, power supply, etc. in the seedling shed to realize automatic control of temperature and humidity control, self-watering and fertilization, spraying and other functions.

[0032] ④Construct a water and fertilizer supply system: According to the total nursery area of ​​the seedling pond, build a nutrient solution pool, a water transfer pool, a medicine pool, a stable irrigation system, and a stable water transfer pipeline and sprinkler and drip irrigation system.

[0033] ⑤Build a clean water pool: The clean water pool is built with specifications of 15.6m×2.5m and a volume of 430m 3 ; Build 2 fertilizer pools, with a size of 3m×6m×2.5m and a volume of 90m 3 The dispensing pool uses three glass fiber reinforced plastic tanks connected in series, each with a capacity of 18m 3 The above specifications of the clear water tank and fertilizer tank are only for illustration. The nursery personnel can also build clear water tanks and fertilizer tanks of other sizes according to actual conditions, which will not be elaborated here.

[0034] In addition, when constructing the seedling shed and the seedling pond, sanitation and disinfection facilities are usually built, and steps such as leveling the pond bottom, dividing the seedling pond and laying anti-weed film are carried out. Since the above steps are technically mature and there are many plans, they will not be repeated here.

[0035] 2) Prepare multiple paper pot trays filled with substrate, sow tobacco seeds in the substrate and place multiple paper pot trays in the seedling pool at intervals, leaving a 2cm-3cm gap between adjacent paper pot trays for adding water and fertilizer;

[0036] The paper pot tray (chain paper pot) includes a plurality of seedling holes with regular hexagonal cross-sections. The seedling holes are connected from top to bottom, and two adjacent seedling holes are connected by a connecting belt of equal length to the side of the seedling hole. When the chain paper pot is used for seedling cultivation, a certain number of seedling holes are folded in a row to fold the chain paper pot into a rectangular structure, and the matrix is ​​loaded into the seedling holes of the paper pot tray. The excess matrix on the surface of the paper pot tray is scraped off to ensure that the matrix in the seedling hole of each paper pot tray is full. 1-2 coated seeds are sown in the seedling holes, with a depth of less than 0.5cm, and 4mm of matrix is ​​covered on the seeds. Then the paper pot tray is placed in the seedling pool. Before the matrix is ​​filled into the seedling holes, it is necessary to add water, stir, and test the moisture content, so that the matrix can be grasped into a ball and fall apart when touched, ensuring that the initial moisture content of the matrix reaches 30%. The moisture content η of the matrix satisfies: η=(M 0 -M 1 ) / M 1 ×100%, where M 0 is the wet sample mass of the matrix, M 1 It is the mass of dry sample after matrix drying.

[0037] 3) Water management: Add water to the seedling pool to make the moisture content of the substrate reach 70-80% until emergence. In other words, during the emergence period when the tobacco seeds break through the soil, add clean water to the seedling pool to allow the paper pot to absorb water until the substrate in the paper pot is completely moistened. Alternate between dry and wet to replenish water intermittently to ensure that the moisture content of the substrate reaches 70-80%, and to ensure that the seeds absorb water, swell, and germinate until emergence.

[0038] After the tobacco seeds in the substrate emerge, wait for the moisture of the substrate in the paper pot tray to evaporate naturally until the moisture content of the substrate is less than 55%. At this time, the tobacco seedlings are in a "dry" environment with alternating dry and wet conditions. Water the seedling pool. After the moisture content of the substrate reaches 70-80%, that is, the tobacco seedlings are in a "wet" environment with alternating dry and wet conditions, repeat the steps of waiting for the moisture of the substrate to evaporate naturally and then watering until the seedlings are grown and transplanted.

[0039] Preferably, the moisture content of the substrate needs to be maintained above 50%, that is, when the substrate is in a "dry" environment with alternating dry and wet conditions, the moisture content of the substrate is between 50-55% (including the breakpoint).

[0040] 4) Fertilization management: 8-12 days after sowing, when 70-80% of the seeds have emerged, apply the first additional fertilizer with water-soluble fertilizer specially used for tobacco seedlings. After emergence, the concentration of water-soluble fertilizer is increased in stages according to the development stage of the tobacco seedlings. During the seedling stage, water and fertilizer management is carried out in the steps of applying water-soluble fertilizer twice and then adding water once;

[0041] Among them, the ratio of nitrogen, phosphorus and potassium in the water-soluble fertilizer for tobacco seedling cultivation is 17:17:17. Watering with clean water once after two fertilizations can dissolve and flush the fertilizer salts remaining in the soil, prevent nutrient accumulation caused by continuous fertilization, and comply with the dry-wet alternating water management principle in step 3.

[0042] 5) Temperature management: from sowing to germination, the temperature in the greenhouse should be kept in the range of 20℃-28℃; from germination to the big cross stage, the temperature in the greenhouse should be kept in the range of 22℃-30℃; after the big cross stage, the temperature in the greenhouse should be kept in the range of 25℃-30℃;

[0043] Seedling growers can use multiple temperature sensors pre-arranged in the seedling shed to detect the temperature at different locations in the seedling pool in real time, and achieve precise temperature control of multiple paper pots. Timely water replenishment can offset the water shortage caused by natural evaporation, and indirectly regulate the ambient temperature around the substrate to create a suitable temperature environment for tobacco seedlings. As the tobacco seedlings grow and develop, timely regulation of the temperature range can also simulate the natural temperature environment, further improving the tobacco seedlings' resistance to stress and environmental adaptability.

[0044] 6) Pest and disease control.

[0045] It is understandable that during the emergence stage when tobacco seeds develop from seeds to tobacco seedlings, water should be replenished in time, and from the emergence stage to the seedling raising stage when the seedlings are transplanted, the dry-wet alternating management steps of waiting for the moisture in the substrate to evaporate naturally and then watering should be repeated, so that the moisture content of the substrate reaches 70-80% during the entire seedling stage. By adjusting the moisture content of the substrate, the moisture supply of the substrate in the paper pot tray is accurately controlled to ensure that the tobacco seedlings are in a dry and wet environment suitable for growth, thereby promoting seed germination and seedling growth, promoting the root development of the tobacco seedlings and improving the stress resistance of the tobacco seedlings.

[0046] In addition, water and fertilizer management under the premise of alternating dry and wet water management can improve the continuity and consistency of tobacco seedling cultivation, facilitate seedling personnel to control the water supply of the substrate in the paper pot tray, and ensure the development of tobacco seeds in the paper pot tray. Compared with traditional floating seedling cultivation or tray seedling cultivation, paper pot tray seedling cultivation only needs to ensure the moisture content of the substrate, and there is no requirement for the horizontal surface of the seedling pool where the substrate is located. It is not necessary to keep the water level of each tray of seedlings the same, which greatly reduces the requirements for the horizontal surface of the pool bottom, especially when cultivating multiple paper pot trays, reducing the workload of seedling personnel. And because there is no need to maintain the horizontal surface of the pool bottom, the bottom of the seedling pool can be replaced by weed-proof cloth instead of a pool membrane to prevent weeds and ensure the growth of tobacco seedlings.

[0047] It should be noted that, in addition to using instruments (weighers and dryers) to detect the weight of substrate samples, in order to determine whether the moisture content of the substrate is less than 5%, at least one of visual inspection, substrate surface tactile inspection, substrate weight comparison and tobacco seedling morphology observation can also be used to determine the surface moisture content of the substrate. Specifically, ① Visual inspection: If the naked eye observes that there is clear water at the bottom of the pond, and the surface of the substrate is not wet (whether the surface of the substrate is whitish or whether there is water reflection in the substrate on the plate under direct sunlight in the morning), and the surface substrate is separated from the paper pots around the seedling holes, then the judgment result is that the moisture content of the substrate is less than 55%, and water needs to be replenished. Otherwise, the judgment result is to postpone water replenishment; ② Tactile inspection of the substrate surface: Insert the fingertips into the substrate 1-2 cm, if it feels dry and loose, the moisture content of the substrate is less than 55%, and water is needed. Otherwise, water replenishment is temporarily postponed; ③ Substrate weight comparison: hold the substrate (or the paper bowl with the substrate) with your hand. If the substrate does not feel obviously heavy, the moisture content of the substrate is less than 55%, and water is needed. Otherwise, water replenishment is temporarily postponed; ④ Observation of tobacco seedling morphology: observe the leaves and roots of the tobacco seedlings. If the leaves show at least one of the following phenomena: wilting, curling edges, and dark green and dull leaves, the moisture content of the substrate is less than 55%, and water is needed. If the leaves turn yellow, or the roots turn brown or rot, water replenishment is temporarily postponed.

[0048] In addition to using the above single method to determine the moisture content of the matrix, users can also use multiple methods for comprehensive determination to further improve the accuracy of the results.

[0049] Among them, the watering amount M of the seedling pool satisfies: a×10.5ml×b≤M≤a×15.8ml×b, where a is the total number of tobacco seeds in each paper pot tray, and b is the total number of paper pot trays.

[0050] By equivalently transforming the above formula, we can get: 10.5ml≤M / (ab)≤15.8ml. In other words, after watering the seedling pool, the average watering amount per tobacco seedling in a single paper pot tray is 10.5ml-15.8ml (including the endpoints). Taking a single paper pot tray with 190 seedling holes as an example, the watering amount required for each paper tray is 2-3L, and the watering amount M of the seedling pool each time is 2×b-3L×b.

[0051] By rationally controlling the amount of water in the seedling pool, we can ensure that each tobacco seedling in a single paper pot tray can be watered in time and avoid excessive watering that causes waterlogging or fertilizer dispersion, thereby ensuring the stable development of the tobacco seedlings.

[0052] In some embodiments, during the water management operation, a pressurized sprinkler system is used to water the seedling pond.

[0053] Exemplarily, in this embodiment, a 1-meter pressurized sprinkler system is used. The 1-meter sprinkler arc covers an area of ​​about 8 square meters, the water output in 1 minute is 4L, and 1 tray of seedlings (60.5 cm long and 30.5 cm wide) is approximately 0.185 square meters. The 1-meter sprinkler can cover about 43 trays of seedlings, and each watering time is about 20 minutes.

[0054] By setting up a pressurized sprinkler irrigation system, it is convenient for seedling growers to accurately control the amount and frequency of water spraying, reduce water resource waste, and improve water utilization efficiency. In addition, the pressurized sprinkler irrigation system has strong adaptability and can be adapted to various layouts of seedling pools and paper pot trays, making it convenient for seedling growers to arrange and use it.

[0055] In other embodiments, in the water management operation, drip irrigation strips or 2.0-2.5 cm Ø plastic pipes are used to water the seedling pond.

[0056] Use drip irrigation strips or Ф2.0-2.5cm plastic tubes to add water slowly by taking advantage of the height difference. This can keep the substrate moist without dispersing the fertilizer, reduce water evaporation, extend the moisture retention time of the substrate, and optimize the development environment of the tobacco seedlings. Drip irrigation strips or plastic tubes are low in price and can reduce the construction cost of the seedling shed.

[0057] Furthermore, in the fertilization management operation: from the seedling stage to the big cross stage, water-soluble fertilizer is added at a concentration of 100-150ppm (200kg water with 180-200g water-soluble fertilizer); after the big cross stage, water-soluble fertilizer is added at a concentration of 200ppm (200kg water with 220-250g water-soluble fertilizer).

[0058] During the emergence stage to the big cross stage of tobacco seedlings, the root system of tobacco seedlings is relatively weak, and water-soluble fertilizers are used for root irrigation or drip irrigation at a concentration of 100-150ppm to ensure the absorption of nutrients such as nitrogen, phosphorus, and potassium while avoiding root burn caused by excessive concentration of water-soluble fertilizers. After the big cross stage of tobacco seedlings, tobacco seedlings enter a rapid growth period, and the concentration of water-soluble fertilizers is increased to increase the ratio of nitrogen, phosphorus, and potassium to promote the growth of tobacco seedlings. The concentration of water-soluble fertilizers is increased in stages according to the development stage of tobacco seedlings to meet the dynamic nutritional needs of tobacco seedlings during the seedling stage, achieve precise fertilization, and greatly improve the growth efficiency and quality of tobacco seedlings.

[0059] It is understandable that when carrying out water and fertilizer management, 5-7 days after adding water and fertilizer, the water at the bottom of the pond is dried up as the standard, and water and fertilizer management should be carried out the next day after the water dries up.

[0060] Wait for the water to dry up and then re-fertilize the next day to avoid excessive nutrient accumulation caused by continuous fertilization, reduce fertilizer waste and avoid burning seedlings. It also makes it convenient for seedling growers to fertilize during normal work and rest hours and reduces their operating pressure.

[0061] It can be understood that in the temperature management operation, water is applied every 2-3 days. If the temperature in the greenhouse is higher than the range that should be maintained, specifically, from sowing to emergence, if the average temperature in the greenhouse or the temperature in some areas of the greenhouse is greater than 28°C, water is applied every 1-2 days; from emergence to the big cross period, if the average temperature in the greenhouse or the temperature in some areas of the greenhouse is greater than 30°C, water is applied every 1-2 days; after the big cross period, if the average temperature in the greenhouse or the temperature in some areas of the greenhouse is greater than 35°C, water is applied every 1-2 days.

[0062] As the temperature rises, the evaporation rate of water in the substrate will accelerate. At this time, it is necessary to increase the frequency of watering and replenish water in time to avoid the rapid evaporation of the substrate and affect the development of the tobacco seedlings.

[0063] It should be noted that when the tobacco seedlings are in an extremely high temperature environment, that is, when the moisture content of the tobacco seedlings quickly drops to 55% or below within 1 day, they can be watered every day to quickly restore the moisture content of the tobacco seedlings to 70-80%.

[0064] It should be added that when the temperature is relatively high on sunny days, the seedling shed can be opened and only the insect-proof net can be retained for timely ventilation and cooling.

[0065] It is understandable that in the operation of disease and pest control, insect prevention should be carried out once before emergence and once again after entering the small cross stage, using high-chloride emamectin benzoate insecticide, diluted and sprayed at 1500 times.

[0066] Furthermore, from the small cross stage to the large cross stage, use 0.5 kg of 50% phoxim emulsifiable concentrate with 5 kg of water and mix with 50 kg of bait to lure and kill ground beetles, crickets, mole crickets, and slugs.

[0067] It is understandable that in the operation of disease and pest control, during the cat period of tobacco seedlings, oligosaccharide·morphoguanidine (to prevent viral diseases), oligosaccharide·tetrazol (75g / mu-100g / mu), and Ningnanmycin agent (1200 times-1600 times liquid to prevent viral diseases) are used to prevent secondary viral diseases; Bacillus subtilis containing 100 billion Bacillus subtilis and a concentration of 5000 times liquid are used to prevent "two black diseases".

[0068] It should be noted that one week before transplanting, the water supply to the tobacco seedlings needs to be controlled. Specifically, the seedling growers should uncover the shade net to increase the amount of light. If the temperature is high on a sunny day, the seedlings can be left uncovered all day. When the tobacco seedlings wilt, use a spray bottle to spray water until all the leaves of the plant are moistened. Cover the seedbed in time when it rains.

[0069] It should also be noted that when the seedlings are 35 to 40 days old, they have grown to four leaves and a bulge, and the plant height is 7cm-10cm, which means they have reached the standard of being able to be transplanted under the flue-cured tobacco film.

[0070] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A tobacco seedling raising method, characterized in that: The following steps are involved: 1) Build a seedling shed and a seedling pool; 2) preparing a paper pot tray filled with a substrate, sowing tobacco seeds in the substrate and placing the paper pot tray into the seedling pool; 3) Water management: adding water to the seedling pool to make the water content of the matrix reach 70-80% until the seedlings emerge, waiting for the water of the matrix in the paper pot tray to evaporate naturally until the water content of the matrix is ​​less than 55%, watering the seedling pool, and after the water content of the matrix reaches 70-80%, repeating the steps of waiting for the water of the matrix to evaporate naturally and then watering until the seedlings are transplanted; 4) Fertilization management: 8-12 days after sowing, when 70-80% of the seeds have emerged, apply the first additional fertilizer with a water-soluble fertilizer specially used for tobacco seedlings. After emergence, the concentration of the water-soluble fertilizer is increased in stages according to the development stage of the tobacco seedlings. During the seedling stage, water and fertilizer management is carried out in the steps of applying water-soluble fertilizer twice and then adding water once; 5) Temperature management: After sowing, the temperature in the greenhouse should be kept in the range of 20℃-28℃; after germination, the temperature in the greenhouse should be kept in the range of 22℃-30℃; after the big cross period, the temperature in the greenhouse should be kept in the range of 25℃-30℃; 6) Pest and disease control.

2. The tobacco seedling raising method according to claim 1, characterized in that: The watering amount M of the seedling pool satisfies: a×10.5ml×b≤M≤a×15.8ml×b, wherein a is the total number of tobacco seeds in each paper pot tray, and b is the total number of paper pot trays.

3. The tobacco seedling raising method according to claim 2, characterized in that: In water management operations, a pressurized sprinkler system is used to water the seedling ponds.

4. The tobacco seedling raising method according to claim 2, characterized in that: In the water management operation, drip irrigation strips or Φ2.0-2.5 cm plastic pipes are used to water the seedling pool.

5. The tobacco seedling raising method according to any one of claims 1 to 4, characterized in that: In the fertilization management operation: from the seedling stage to the big cross stage, the water-soluble fertilizer is added at a concentration of 100-150ppm; after the big cross stage, the water-soluble fertilizer is added at a concentration of 200ppm.

6. The tobacco seedling raising method according to any one of claims 1 to 4, characterized in that: When managing water and fertilizer, 5-7 days after adding water and fertilizer, use the drying up of the water at the bottom of the pond as the standard, and add water and fertilizer on the second day after the water dries up.

7. The tobacco seedling raising method according to any one of claims 1 to 4, characterized in that: In temperature management operations, water the plants once every 2-3 days. If the temperature in the greenhouse is higher than the range that should be maintained, water the plants once every 1-2 days.

8. The tobacco seedling raising method according to any one of claims 1 to 4, characterized in that: In the operation of disease and pest control, carry out insect prevention once before emergence and again after entering the small cross stage. Use high-chloride emamectin benzoate insecticide and dilute it by 1500 times for spraying.

9. The tobacco seedling raising method according to claim 8, characterized in that: From the small cross stage to the large cross stage, use 0.5 kg of 50% cypermethrin emulsifiable concentrate with 5 kg of water and mix with 50 kg of bait to lure and kill ground beetles, crickets, mole crickets and slugs.

10. The tobacco seedling raising method according to any one of claims 1 to 4, characterized in that: In the operation of disease and pest control, during the cat period of tobacco seedlings, oligosaccharide·morphoguanidine, oligosaccharide·chain protein, and Ningnanmycin agents are used to prevent secondary viral diseases; Bacillus subtilis containing 100 billion Bacillus subtilis and a concentration of 5000 times are used to prevent "two black diseases".