How to fertilize onions?

How to fertilize onions? How many times do I need to top dressing? Also ask experienced netizens to help introduce that crops need to be fertilized according to different periods after planting, and onion planting is no exception, so the farming network has sorted out the three-stage topdressing methods of onions, which are listed in detail below for netizens' reference. 1. Topdressing of onion at slow seedling stage: slow down seedling fertilizer 15-20 days after onion planting, replenish nutrients for root growth and prepare for aboveground growth that will begin soon. Urea 5kg / mu was sprinkled and watered to facilitate absorption and utilization. Second, the topdressing of onion growth stage: generally, 30 days after onion planting, when the vegetative growth is strengthened, topdressing fertilizer should be applied to ensure the growth of aboveground functional leaves. Because the size of the leaf vegetative body is closely related to the size of the bulb, and the promotion of leaf growth in the early stage lays the foundation for the hypertrophic growth of the bulb in the later stage. Mainly nitrogen fertilizer, 5kg urea and 5kg potassium sulfate per mu. Third, onion topdressing at the first stage: after the onion plant has 8 or 10 tubular leaves, the bulb begins to expand, and the head fertilizer should be applied once. The head fertilizer should focus on the middle stage of bulb expansion and growth. Nitrogen fertilizer should not be applied too much at the beginning of bulb growth. If excessive nitrogen fertilizer is applied in the later stage of bulb expansion, greed will occur and harvest will be affected. Urea 5kg / mu and potassium sulfate 8kg / mu. In the bulb expansion period, potassium deficiency will not only reduce the yield, but also have a certain effect on the storability of the product. Onion high-yield planting method onion seedling method