Key Cultivation Techniques and Field Management Methods for Onions

The onion is a perennial herbaceous plant of the Liliaceae family and the genus Allium, and it is also a vegetable eaten in daily life, so what exactly are the onion cultivation techniques?

I. Growth habits of onions

The onion originated in Central Asia or West Asia, and is now cultivated all over the world. It is a biennial or perennial herbaceous plant, with linear roots and dark green leaves. The leaf sheaths are thick and scale-like, densely clustered around the shortened stem to form a bulb (commonly known as an onion head).

After the radicle of the onion enters the soil, it soon shrivels. Because it has no main root, its drought tolerance is relatively weak, and its ability to absorb water and nutrients is relatively weak.

The onion has strong adaptability to temperature. Seeds and bulbs can germinate slowly at 3-5°C, and the suitable growth temperature for seedlings is 12-20°C. Allium is a long-day crop, requiring more than 14 hours of long-day conditions during the bulb enlargement stage and the bolting and flowering stage, and sufficient water should be supplied during the germination stage, the vigorous seedling growth stage and the bulb enlargement stage.

II. Onion cultivation techniques

1. Land preparation: choose fertile soil with good water retention for sowing, then plow and apply base fertilizer;

2. Transplanting: select excellent onion varieties suitable for local planting for raising seedlings, and after the seedlings are ready, transplant them at a certain spacing;

3. Other management: during the onion growing period, weed, water and fertilize in a timely manner.

About 20 days after the onion is planted, it enters the seedling recovery stage. Because the temperature is relatively low at planting time, a large amount of watering should not be done. Excessive watering will lower the soil temperature and make the young plants recover more slowly.

For the fertilizer requirements of onions, each mu requires 13-15 kg of nitrogen, 8-10 kg of phosphorus and 10-12 kg of potassium. Pay attention to the application of phosphorus and potassium fertilizers, and avoid excessive nitrogen fertilizer, so as to prevent overly vigorous aboveground growth that leads to bolting or delays bulb enlargement.

For spring-sown onions, the soil should be kept moist before and after the seedlings emerge, with frequent watering and intertillage. The vigorous leaf growth stage and the bulb enlargement stage are the periods of greatest fertilizer and water demand for onions, so fertilizer and water should be applied in a timely manner, with 15 kg of diammonium phosphate, 20 kg of diammonium phosphate and 3-5 kg of potassium sulfate applied as topdressing per 667 sq m respectively.