Today, the agricultural technology basket will tell you about the above-mentioned onion planting technology knowledge. You can look at it and learn it to prepare for the upcoming autumn onion planting.
1. How many times can green onions be planted a year? When do you plant onions every time? Which season is the best for planting green onions?
Generally, green onions planted in the open field can be planted three times a year (they can be planted in greenhouses all year round). Green onions are called spring onions, summer onions are called summer onions, and autumn onions are called autumn onions. Onion is mainly planted around Tomb-Sweeping Day in spring (March-April), so it is also called Qingming Onion. Green onions are planted in summer, because they are mainly planted after summer (July-August), so they are also called summer green onions. In autumn, green onions are mainly planted around autumn dew (September-65438+1October), so autumn dew green onions are also called white dew onions.
Although green onions can be planted in the open field all year round, they are actually planted mainly in spring and autumn. Compared with scallion and summer scallion, autumn scallion is the largest variety with the largest planting area, and it is also the variety with the best growth, the highest yield and quality, and the longest time to market, which is directly related to the growth characteristics of scallion, which likes cold but does not like heat and is not resistant to high temperature and strong light.
Generally speaking, green onions planted in spring can be used as fresh green onions in summer, or as green onion seedlings planted in summer (we call them green onion seedlings), which can also be harvested in autumn and eaten in winter; Green onions planted in summer can be harvested and eaten after autumn, or used as green onion seedlings planted in autumn, or used as green onion seeds after germination in the following spring; The green onions planted in autumn are generally harvested and marketed around spring, or used as green onions planted in the next spring.
As far as the sowing, seedling raising, transplanting and harvesting time of autumn green onions is concerned, the autumn green onions are generally sown in March-April, transplanted in May-June and harvested in February, while the winter green onions are generally sown in April-May, transplanted in June-July and harvested in February. The green onions harvested in the summer and autumn of that year and the following spring are generally sown in May-September, transplanted and planted in September-165438+1October, and harvested in May-June of the following year. Onions harvested in spring and summer in winter are usually sown in September-10+02.
As far as the annual planting temperature of green onion is concerned, because green onion likes cold and is not resistant to high temperature, it is generally suitable to plant green onion in the range of local temperature stability 15-25 degrees, and it is not suitable to plant green onion when the ground temperature is too low or the climate is hot. Generally speaking, when planting green onions in low temperature season, it is suggested that you wait until the local average temperature rises above 15 degrees before raising seedlings or transplanting. Planting green onions in high temperature season, the agricultural technology basket suggests that you wait until the average temperature drops below 20 degrees before sowing seedlings or transplanting. If the temperature is too low or too high when planting green onions, it will not only affect the normal germination and emergence of green onions, but also seriously affect rooting or lead to emergence.
Soon, everyone will begin to prepare for sowing and seedling raising of autumn green onions. The agricultural technology basket here suggests that you try to choose the Millennium-autumnal equinox (from mid-late September to1early October), which is a time period with suitable temperature and humidity. Planting green onions too early or too late is not conducive to the normal germination, emergence and growth of green onions. For example, early planting of green onions is prone to overgrowth or premature bolting. Onions planted too late will not be safe in winter (they are easy to be frostbitten or freeze to death in winter) because the onion seedlings are too small and tender (they can't reach the standard of two leaves 1 heart before winter).
2. What are the basic conditions for planting high-quality green onions?
First, the green onion planting site must be fertile, loose and transparent, with good water and fertilizer conservation capacity (it is recommended to choose light sand soil with good water and fertilizer conservation capacity to plant green onions). Due to the shallow soil, few roots, few fibrous roots (root hairs), underdeveloped roots, neither drought resistance nor waterlogging tolerance, the root system has poor ability to absorb water and fertilizer.
Secondly, foot fertilizer (organic fertilizer+NPK fertilizer) and topdressing must be applied in onion planting areas, especially in topdressing management during onion growth, more nitrogen fertilizer should be applied in the early stage of onion growth to promote the rapid growth of onion seedlings, and more phosphorus fertilizer and potassium fertilizer should be applied as much as possible in the middle and late stage of onion growth to enhance the robustness of onion growth, increase the single weight yield of onion and improve the taste quality of onion.
Thirdly, during the growth of Chinese onion, we should keep the soil moist, free from water shortage and drought, and provide suitable soil moisture conditions for the growth of Chinese onion. At the same time, we should pay attention to strengthening soil cultivation management in the field after the middle growth period to promote the formation of Chinese onion and greatly improve the taste, quality and appearance of Chinese onion.
3. What technical problems should be paid attention to when sowing and raising seedlings of scallion?
First, do a good job in disinfection and sterilization management of onion seeds before sowing. Before sowing, you can put onion seeds in the sun for a sunny day, then stir them with warm water of 55 degrees continuously 15 minutes before sowing, or soak them with potassium permanganate, carbendazim and agricultural streptomycin 10-20 minutes.
Secondly, when the soil temperature is low (especially when planting green onions) and the germination rate is slow, the green onion seeds can be soaked first and then placed in a temperature and humidity environment of about 17-22 degrees for 2-3 days, and then sown after most seeds germinate and turn white, which can promote the germination of green onions and make them emerge faster after sowing. If green onions are sown in summer and autumn when the temperature is high, there is generally no need for heat preservation, moisture retention and germination.
Thirdly, in order to ensure the germination and emergence rate of Chinese onion after sowing, it is not recommended to use old onion seeds with low seed vigor and low germination rate, and try to choose new onion seeds with high vitality and high germination and emergence rate. In general, the sowing amount of old seeds is 1.5-2 times more than that of new onion seeds to ensure normal germination rate.
Fourth, we should master the sowing depth when sowing onion seeds. Before sowing green onions, water them to make them wet. When sowing, the Chinese onion seeds should be drilled or sowed along the ditch, and the sowing depth is generally about 1.5-2 cm. After sowing, cover the seeds with plant ash or fine soil with a thickness of about 0.8- 1 cm to protect the seeds.
Fifth, from sowing to germination, we should pay attention to keeping the seedbed warm and moist (if necessary, cover the seedbed with plastic film or sprinkle fine straw after sowing, and remove the plastic film from the ground when the seedlings grow to 2-3 hectares). After three to five days, onion seeds can germinate and emerge one after another.
Sixth, wait until the shallot seedlings emerge and the cotyledons of the shallot seedlings are fully unfolded. Generally, as long as the soil is not dry at noon and the seedlings are not withered, water them as little as possible. When all the green onion seedlings come out, attention should be paid to timely thinning in places where the seedlings are too dense; When 2-3 leaves grow on the green onion seedlings, if the green onion seedlings grow yellow and weak, they can be sprayed or watered with dilute urea solution, but the amount of urea should not be too large.
Seventh, when the scallion seedlings reach the seedling age standard suitable for transplanting and planting, they can be transplanted and planted in time, and can be transferred to normal management after survival. When raising seedlings, water them first and then raise them with clods (to avoid excessive root damage). When planting, we should pay attention to the classification and sowing according to the size and health of onion seedlings, which is convenient for unified management in the later stage. When planting onion seedlings, we should plant them according to the best depth of "no onion heart leaves buried above and no onion roots leaking below". If planted too deep, it will not only cause onion seedlings to rot, but also be detrimental to the slow survival and rooting of onion seedlings. If the planting is too shallow, it is easy to appear.