Cultivation techniques of onion

Onion is a perennial herb of Liliaceae and onion genus, and it is also a vegetable eaten in daily life, so what is the cultivation technique of onion?

I. growth habits of onions

Onions are native to Central or Western Asia and are now cultivated all over the world. They are biennial or perennial herbs with linear roots, dark green leaves, thick scaly leaf sheaths and bulbs (commonly known as onions).

The radicle of onion will shrink soon after it is buried in the soil. Because there is no main root, its drought tolerance is weak and its ability to absorb fertilizer and water is weak.

Onions have strong adaptability to temperature. The seeds and bulbs could germinate slowly at 3 ℃, and the suitable temperature for seedling growth was 12 ℃. Onion belongs to long-day crop, which needs more than 14 hours of long sunshine in bulb expansion stage and bolting and flowering stage, and sufficient water should be supplied in germination stage, seedling growth stage and bulb expansion stage.

II. Onion cultivation techniques

1. Soil preparation: select fertile soil with good water retention to sow, then plough and apply base fertilizer

2. Transplanting: select excellent onion varieties suitable for local planting to raise seedlings, and transplant them according to a certain distance after the completion of raising seedlings.

3. Other management: weeding, watering and fertilization should be carried out in time during onion growth.

Onions entered the slow seedling stage about 20 days after planting, because the temperature was low during planting, so they could not be watered in large quantities. Too much watering would lower the ground temperature and slow down the seedlings.

According to the fertilizer requirements of onion, nitrogen 13~15kg, phosphorus 8~10kg and potassium 10~12kg are required per mu. Pay attention to the application of phosphorus and potassium fertilizer, do not overweight nitrogen fertilizer, so as not to cause overgrowth of aboveground parts and bolting or delay bulb expansion.

Spring sowing onion seedlings should keep the soil moist, watering and ploughing frequently before and after they are unearthed. During the peak leaf growth period and bulb expansion period, onion needs fertilizer and water the most, and timely fertilization and watering should be done. Diammonium phosphate 15kg, diammonium phosphate 20kg and potassium sulfate 3~5kg should be applied to 667 square meters, respectively.