How to grow onions

1. Land preparation and fertilization

Onions should not be grown continuously, nor should they be repeated with onions and garlic vegetables. The onion root system is shallow and has weak absorption capacity, so the cultivated land should not be deep, but it needs to be fine. To cultivate onions in autumn, the land needs to be plowed after the previous crop is harvested, with a depth of about 15cm. After the cultivated land is completed, the border can be made. The size of the border needs to be determined according to the local climate conditions. Generally speaking, a wide border of about 2m wide and 10m long can be built to improve land utilization and increase the number of plants per unit area

2. Established crops

(1) Graded seedling selection. When planting, select seedlings that grow robustly and have uniform sizes; eliminate leggy seedlings, dwarf seedlings, diseased seedlings and branched seedlings, and seedlings that grow too large or too small. The seedlings are graded according to their thickness and height, and are generally divided into three levels: first-level seedlings are about 15cm tall and 0.8cm thick; second-level seedlings are 12cm tall and about 0.7cm thick; third-level seedlings are about 10cm tall and 0.6cm thick. Plant seedlings of the same level together

(2) Planting density. Reasonable and dense planting of onions is one of the key measures to increase onion production. Generally, the row spacing is 15-18cm, the plant-to-plant spacing is 10-13cm, and about 30,000 plants are planted per acre. The density of planting should be determined based on the variety, soil, fertility and seedling size. Generally, early maturing varieties should be planted densely, red onions should be sparse, soil with poor fertility should be dense, and large seedlings should also be planted sparsely. The maximum density is the premise to ensure the size of the onions.

(3) Colonization time. Onions cultivated in autumn need to survive the winter, so the planting time is appropriate to allow the root system to resume growth after planting without causing plant growth. Planting too early will cause the overwintering seedlings to be too large and prone to early bolting the next year; planting too late will cause the root system to not resume growth, and the overwintering process will be prone to frost damage. Generally, it is advisable to plant 30 to 40 days before the onset of severe cold. The general planting time in Luohe area is from the end of October to early November

3. Field management

(1) Watering. Onions enter the slow seedling stage about 20 days after planting. Since the temperature is relatively low during planting, large amounts of watering cannot be done. Excessive watering will lower the ground temperature and affect the growth of the seedlings.

(2) Fertilization. The fertilizer requirements for onions are 13 to 15 kg of nitrogen, 8 to 10 kg of phosphorus, and 10 to 12 kg of potassium per acre.

(3) Cultivate and loosen the soil. Loose soil is conducive to the development of onions and the expansion of bulbs. Generally, it should be carried out 3 to 4 times in the seedling stage, combined with each watering; it should be carried out 2 to 3 times in the growth period of stems and leaves, and the depth of cultivating should be about 3cm

4) Remove stems. For onions that have bolted in advance, cut off the lower part before the flower bulb is formed to prevent flowering from consuming nutrients, promote the growth of side buds, and form a more substantial bulb. At the same time, spray Diguo Zhuangdi Ling in a timely manner.