It is better to choose sandy loam for onion cultivation.

Select the land with flat terrain, good irrigation conditions, less than 0.2% salt content of groundwater, neutral and high fertility of the soil, sandy loam and non-stubble land. The American improved 502 onion variety was selected. Raising seedlings: generally, it is most suitable to raise seedlings in 1-2 days before and after "White Dew". Premature bolting is easy to occur, and the yield will be reduced if it is too late. After finishing the bed, irrigate enough water, sow seeds and fine sandy soil at the ratio of 1 ∶ 10, cover fine soil with a thickness of about 1 cm, and apply phoxim granules to prevent underground pests after sowing. The amount of seed used in the seedling bed was 2 kg / mu, and about 25000 seedlings emerged. Colonization: generally in late October (Frosts Descent) before and after planting is appropriate. 5000 kg of rotten organic fertilizer, 50 kg of diammonium phosphate and 50 kg of superphosphate were applied per mu, and the depth was 30 cm after fertilization, combined with spraying fluralin EC to control weeds and phoxim granules to control underground pests. Select seedlings with a height of about 20-25 cm, a stem diameter of 0.6-0.9 cm (no more than 1 cm), and 4-5 leaves. If the seedling is too large, it is easy to cause bolting and flowering; if the seedling is too small, it is easy to freeze to death when overwintering. The row spacing is 20 cm, the plant spacing is 15 cm, and 22000 seedlings are planted per mu. It is advisable to bury the bulb by 1 cm and not to float the seedlings after watering. Management from planting to turning green: watering immediately after planting, water infiltration, and timely ploughing. Pour enough frozen water before freezing (mid-November) and cover with plastic film. Do a good job of film protection in winter, find holes in time to block strictly, strictly prevent frozen seedlings.