Topdressing after slow growth of seedlings, a small amount of topdressing can be combined with irrigation, with 5 kg of ammonium nitrate per mu, 65,438+05 kg of urea in dihydrate and 65,438+05-20 kg of ammonium nitrate in tetrahydrate. Spraying potassium dihydrogen phosphate for 2-3 times during the whole growth period. There are many varieties of onion, so it is not advisable to blindly introduce inappropriate varieties to avoid economic losses. Onion seeds should be treated with seed dressing. Before sowing, pick out withered pests and pests, and then dry them in the sun for two days to control the spread of germs. If the overwintering seedlings are too big, onions spring in the green body.

If the moss is pulled out in advance in the second year, the leaf sheath will not expand into bulbs. Onion has shallow root distribution, weak absorption capacity, no tolerance to water stains, and it is easy to grow wildly when the humidity is high. Sandy loam with rich organic matter and strong water retention is better. During the vegetative growth period, the stem of onion will be shortened, forming an oblate cone-stem disk, the lower part of the stem disk is the heel, and the roots will grow in the heel. After maturity, the heel tissue of bulbs usually rots and hardens. It can prevent water from entering the scale.

If we want to increase onion production, we should choose sandy soil as much as possible. If the onion has good color and storage, cohesive soil is the most suitable choice. No matter what you plant, you should choose soil with more organic fertilizer so that plants have sufficient nutrients. In this environment, it is also beneficial to the expansion and high yield of drip bulbs. In addition, its root system is underdeveloped and its absorption capacity is weak, but its growth period is long, its yield is large, and its demand for nutrients is large, and its demand for potassium, nitrogen, phosphorus and calcium is relatively large. When planting onions, we should start from the following nine aspects.

In this environment, it is also beneficial to the expansion and high yield of drip bulbs. In addition, its root system is underdeveloped and its absorption capacity is weak, but its growth period is long, its yield is large, and its demand for nutrients is large, and its demand for potassium, nitrogen, phosphorus and calcium is relatively large. When planting onions, we should start from the following nine aspects. The planting time should be165438+1October. Add 4000 kg of farm manure per mu, use 100 kg of diammonium phosphate, keep the row spacing at about 15cm, and then cover it with plastic film, so that it can survive the winter better.