Technical points of asparagus seedling raising in spring;
1. Nursery site: loose soil, fertile soil and sandy loam with good air permeability are selected, with watering and drainage conditions and an open and ventilated environment. Because asparagus, onion and garlic are all Liliaceae crops, in order to reduce pests and diseases, the plot where the previous crops are onion and garlic is not suitable for asparagus seedling cultivation or cultivation.
2. Seedling raising methods and seedbeds: mainly including seedling raising in solar greenhouse, seedling raising in plastic small arch shed, seedling raising in sunny slope and seedling raising in open field. Advocate nutrition bowl seedling. When transplanting, the root damage is small and the survival rate is high.
Third, soaking seeds to accelerate germination: asparagus seeds have hard skin, strong keratinization, difficult water absorption and slow germination. In order to promote seed germination, germination must be accelerated before sowing. Before sowing, the seeds can be dried in the sun for 1 ~ 2 days, then the chaff seeds and moth-eaten seeds are bleached with clear water, soaked in 300 times of 50% carbendazim10 ~/2 hours, soaked in warm water at 30℃ ~ 35℃ for 2 days, and changed with water 1 ~ 2 times a day.
4. Sowing: Before sowing, water the seedbed in the nutrition bowl or the seedbed in the open field, spread a thin layer of soil after water seepage, mark the seedbed in the open field according to the row spacing of 10cm, or cut the square soil with the depth of 10cm with a knife, take a germinated seed and sow it in the center of the grid or the nutrition bowl, cover it with medicinal soil for 2-3 cm, and cover it with a film after sowing. You can also sow in the open field or drill holes in the furrow.
Five, seedbed management:
1. temperature: the suitable temperature for asparagus germination is 25℃ ~ 28℃, and the suitable temperature for seedling raising in small arch shed or sunny bed is 25℃ ~ 28℃ during the day and 15℃ ~ 18℃ at night. At 25℃ during the day after emergence, the lowest is not lower than 8℃ and the highest is not higher than 30℃, and outdoor air is released in time. And gradually increase ventilation and hardening seedlings to adapt to the external environment. When the seedlings have more than three stems on the ground, they can be planted.
2. Water and fertilizer: Before emergence, the seedbed soil should be kept moist, otherwise it should be watered in time. After emergence, the root system of seedlings is weak, so it should be watered in time during drought. When the seedling height is about 10cm, rare organic liquid fertilizer can be applied once with the water, such as fully decomposed human manure or biogas slurry, or urea and potassium chloride can be applied with the water, and topdressing can be carried out 2-3 times at the seedling stage, so that the seedlings can fully accumulate assimilated nutrients in the later growth stage and cultivate strong seedlings.
3. Intertillage weeding: after emergence, remove the plastic film immediately. After the seedlings are sown together, the seedlings should be spaced apart, with the spacing of 7 ~ 10 cm. Weeding should be done frequently when raising seedlings, and intertillage and loosen the soil in time. Properly cultivate soil to make scales and buds grow sturdily and prevent seedlings from lodging. When the seedlings reach the standard of planting seedlings, they can be planted: the height of asparagus seedlings is about 0.3m, more than 3 stems on the ground and 5 roots stored underground.