Technical management measures for cultivating strong seedlings of spring cabbage

The sowing and breeding period of spring cabbage is in the cold winter season. In order to avoid frost injury and safe production, we have adopted improved Xiaoyang bed to cultivate high quality and strong seedlings in recent years, and achieved successful experience. The improved Xiaoyang bed has the characteristics of fast heating up and good heat preservation performance. it has higher light transmittance and stronger light than the previous simple seedbed, and can increase the seedbed temperature by 3 Mel 5 ℃, which farmers call "small greenhouse". Now the supporting techniques are introduced as follows: first, the selection of the improved Xiaoyang bed, the bed site should be selected in the fields with shelter from the wind and the sun, convenient water conservancy, fertile soil and previous crops of non-cruciferous crops. Second, the facility material length 2 meters small bamboo pole 25mur30, or the length 3 meter bamboo pole 1214pieces. One kilogram iron wire, six kilograms, one kilogram wire, three kilograms, four kilograms. The length is 50 Mel 60 cm, the horizontal diameter 6 mi 8 cm, the stake 8 mi 10, the length 2 m, the horizontal diameter 6 mi 8 cm, and the wooden pole 3 mi 5. Corn or sorghum straw 50ml 75kg, silk or rope 0.5ml 1kg. Basic construction of a modified small sunny bed, which is composed of a frame, a cover and a windshield wall. The frame includes wall frames, wiredrawing, arches and wooden piles. The covering is greenhouse film. The wind shield, also known as the wind screen, is usually tied up with corn and sorghum straw and is located outside the north wall of the sunny border to block and slow down the cold wind from the north. 2. Xiaoyang border sits from north to south. The north wall is 75mi 90cm high, the south wall is 15m / 20cm, and the east-west gables are gradually rising from south to north. The size of the sunny border varies with the planting area. For every mu of field planted, the seedbed area is 123,15 square meters. A small sunny border is usually built, which is 8m long from east to west and 2.5m wide from north to south, which can cultivate 2 mu of high-quality seedlings in the field. The wind shield is about 12 meters long from east to west and 2 meters high. 3. The construction is mainly the construction of earth walls. After the border was delineated, the soil was dug around the border to build the wall, so that the height of the north wall was 60 cm higher than that of the south wall, and the east-west gable was higher in the north and lower in the south. After the wall frame is cultivated, it is cut into a smoother wall with a thickness of about 35 cm. Then flatten the ground. Finally, the wind shield is made. The method is to draw a line 1 meter behind the north wall, which should be 2 meters longer than the north wall, then dig 5 pits at an equal distance on this line, plant a 2-meter-long wooden pole, tie 3 wires on the pole, and tie the crop straw to the wire to form a wind shield. 4. Fertilize the border bed with 500 kg of manure with high content of organic matter, 15 kg of special fertilizer for vegetables, or 1 kg of urea, 10 kg of superphosphate and 5 kg of potassium sulfate. After applying fertilizer, rake the ground so that the soil and fertilizer are mixed evenly, and then make a bed. For the convenience of management, two small borders can be made in the general sunny border. 5. For the cultivation of improved spring cabbage, early or mid-early maturing varieties with strong winter character, low temperature and weak light resistance, immature bolting resistance, high quality and disease resistance should be selected in order to put them on the market earlier and increase the benefit. Such as: Zhonggan 10, 11, 15 and 21, with iron balls, praise, knights and other small foreign varieties. The amount of seed used in each mu of field is 50ml and 60g. 6. The suitable sowing time is in the middle and late December. It is appropriate to have a seedling emergence and growth period of 15 days from Lesser Cold after sowing. Pour water into the seedling bed before sowing, fill the bed surface with nutrient soil before sowing, and then sow seeds. The seeding rate of nursery bed is 3ml / m2 and 4g / m2. The sowing rate should be strictly controlled to prevent the seedlings from being too dense. The thickness of soil cover after sowing is 0.5ml 0.7 cm. 7. Cover the east-west wall with 1 inch of iron wire and fasten the big ends of the wooden stakes to the outside of the gable with a bandage of 0.7 Mill and 0.8 meters apart and 4 rounds of wire drawing. After that, a small bamboo pole was used to tie 14 arches on the wire every 0.7m to 0.8m. Finally, cover the greenhouse film. First, the front film edge is buried and pressed by trenching in front of the south wall, and one side of the north wall is used as the entrance and exit for ventilation and nursery bed management. the film edge can be laid flat on the wall and pressed with bricks, and the wind is released to pull 5 Mustang and 6 pressure film lines on the film surface to prevent the wind. 8. Seedbed management is not ventilated after sowing to before the appearance of the first true leaf. After the appearance of the first true leaf, the ventilation begins, and the tuyere becomes larger and larger for exercise. During this period, the seedling bed temperature was kept at 15 ℃ 20 ℃ during the day and 8 ℃ at night. Then, depending on the seedling situation, choose the sunny noon seedling to pull the grass. The main purpose of interseedling is to remove yellow, thin, weak and small seedlings. The new method of raising seedlings and changing the previous one-stage cultivation of undivided seedlings is to achieve high-quality and strong seedlings through the implementation of secondary cultivation. Make the seedling bed one week before the seedling division. Seedbed requirements: the soil is fertile, loose, flat, and a soil treatment is carried out to sterilize and kill insects and improve the seedling rate. Three days before seedling separation, properly reduce the night temperature of the seedling bed and exercise again to enhance its adaptability. The seedling was divided at the stage of 3 true leaves of the seedling. Choose fine weather and use the method of dividing seedlings from time to time. That is, the big seedlings are selected in the seedling bed for transplantation, leaving the small seedlings to be nurtured. Pulling seedlings should pay attention to handle gently, do not damage leaves, do not hurt roots, and try to bring the original soil. The method is: first open a ditch to water, and then plant seedlings to bury the soil. The row spacing is 8 cm square. After the division, cover it with a small bow shed and pay attention to heat preservation and cold protection. There was no ventilation within 3 days, and the seedlings were refined with appropriate ventilation according to the situation of the seedlings after 3 days. The temperature of the nursery bed was maintained: 14 ℃ for 15 min during the day and 7 min for 8 ℃ at night. Large ventilation and strong seedlings were carried out 15 days before planting. First release the strong wind to train the seedlings to adapt to the field environment for 7 days, and then remove all the mulch so that the seedlings can be transferred to the open environment. The strong seedlings were planted when the seedling age was 60 ~ 70 days and the seedlings reached the appearance standard of "sturdy stems with 6 leaves, thick leaves and green leaves, well-developed root system without disease insects".