Turn the sun deep first, then arrange and rake the mortar to make a deep ditch. Usually the width is 2 meters (ditch), the width of ditch is 50 cm, and the depth is 50 ~ 60 cm. Stop the forefoot base fertilizer, a fertilizer made of 2000-2500 kg of rotten farm manure (such as pig manure), 50 kg of peanut bran and 75 kg of calcium superphosphate. When you stop working, you should make the soil fine, the ditch straight, the water level and the fertilizer uniform. At the same time, spray herbicides on the dough.
The suitable broadcast time is from the middle and late July to the end of September, and the best broadcast time is from the middle and late August. 50 ~ 90kg per mu, with a general plant spacing of 22cm and a row spacing of 25cm, and blood sugar scales 1 ~ 2. In order to improve the initial yield, add a row (simplified wave) to the row spacing, and harvest the whole plant at the first harvest. Before broadcasting, soak it in 500 times of 50% carbendazim humidified powder for 5 ~ 10min, then take it out and dry it for broadcasting.
The shallow water species should be 2/3 ~ 3/4 of the onion that has not been buried. After sowing, water it thoroughly once, preferably the dough is soaked. Seedling can be captured in 7 ~ 15 days. When the height of seedlings is about10cm, apply water fertilizer thinly once, and sprinkle 3 ~ 5kg urea in 500kg rotten livestock manure per mu to improve the root growth and seedlings. In the future, apply fertilizer once every10cm. The stunt is that in early autumn, the weather is dry and you have to water it once a day or two. At this time, when it is hot and dry, attention should be paid to preventing grave robbery.
When the onion seedlings are about 20 cm long, combine weeding in Chongqing for topdressing to promote growth and pollination. Usually, 20 ~ 40 kg of ternary compound fertilizer and 5 ~ 10 kg of urea are applied per mu and poured into the pitcher at the same time. Water should be decided according to the weather, and the flour turns slightly white, so water it in the morning and evening. Too much water, onion leaves grow too fast, affected by the growth of onion white, easy to get sick, easy to faint, onion turns red. After that, topdressing is usually done once every 10 day.
The main diseases are purpura, rust, downy mildew, leaf blight, gray disease and plague. The main pests are horses, semi-submersible flies, papaya, beet armyworm and Spodoptera litura. Agricultural measures such as crop rotation, removing diseased leaves, improving field hygiene, controlling water and fertilizer, etc. are adopted to prevent pests and diseases. At the same time, based on physical control such as frequency, food intake and insecticide, chemical control is improved. When the scallion is eaten by 100 insects in the field, reaching 50 ~ 100, chemicals should be sprayed immediately to prevent it. You can choose 10% for mite 2500 times, 40.7% for Ruben 1000 times, 40% for thistle 1000 times, 20% for good winter 1000 ~ 2000 times, and 5%. Spraying once every 8 ~ 10 days, usually 2 ~ 3 times continuously, can effectively prevent it.
When the flower wavelength reaches an appropriate height, the whole plant should be taken out in time, so that the onion with regular row spacing can grow strong and pollinate. The usual Gru-spaced school should be harvested in batches in time when it is suitable for listing. In other words, 1 ~ 2 strains of blood sugar should be left as the mother plant, and the rest should be pulled out. Protect the remaining raw wine when extracting onions, and compress the exposed roots when extracting onions with a small amount of soil. Water the soil once when it is dry. If you don't smoke onions, the onion weeks will grow, the powder will be fast, the plants will become thinner and thinner, and the diseases and insect pests will be aggravated, which will affect the quality of onions.