Scallion planting and management ①Land selection scallion nursery beds should be selected flat terrain, fertile ground, drainage and irrigation is convenient, deep layer of loamy soil plots. Stubble should be selected within three years without planting onion and garlic class of land, suitable for crop rotation with grain fields or other vegetable fields. Shallots are also a good precrop for vegetables other than onions and garlic. Onions are more shade-tolerant, and can be inter-cropped with other vegetables.

② land, fertilization shallot seedling period is long, should apply enough fertilizer. Generally per hectare of rotting organic fertilizer or soil fertilizer 32500-45000 kg, shallow turning, harrowing, made of flat beds. When possible, additional calcium superphosphate can be applied 375 kg. When the underground pests are serious, the poisonous grain can be used to prevent and control. Before sowing, spray no deep plowing soil conditioner, 200 grams per 667 square meters, add 100 kg of water, spray cloth ground, can make the soil loose, conducive to the development of the root system and more water storage, to prevent drought in winter and spring seasons.

③ sowing time Onion seedlings suitable effective growth time of 80-90 days, before reaching the standard of planting. In the cultivation of winter onions, first of all, according to the local climatic conditions, to determine whether it is autumn or spring sowing. Generally the frost-free period in the region below 180 days need to be sown in the fall; more than 200 days of the region suitable for spring sowing; frost-free period between 180-200 days of the region, spring sowing, fall sowing can be. This is because the growth period is not enough, the plant can not fully develop; and the growth period is too long, the leaf exuberant growth period is prone to early failure, also can not achieve the purpose of high yield. The majority of the northern region to fall sowing. North China autumn sowing in late September is appropriate, cold areas should also be early, warm areas should be slightly pushed back. Shandong region more in early October sowing. Sowing period to determine the standard is: to seedlings before the winter has 40-50 days of fertility, can grow into 2-3 true leaves, plant height of about 10 cm, stem thickness of 4 mm or less is appropriate. Such physiological seedling age seedlings can safely overwinter, but also can reduce the following year first draw shoot phenomenon. When sowing in the fall, the average ten-day air temperature of 16.5-17 ℃ for sowing the most suitable, to ensure the effective growth of cumulative temperature (7 ℃ above) 660-700 ℃ can be. Sowing too early in the fall, the next year, the first shoot phenomenon is serious; too late, the seedlings are too small, easy to freeze in winter. Spring sowing, should be sown as early as possible. North China at the end of February to early March that should be top sowing. The later the sowing, the smaller the seedlings; the lower the yield. Shandong region where the spring sowing of onion seedlings, transplanting, than the autumn sowing seedlings small, light leaf color, thin leaf flesh, onion white short, not full, yield is also reduced.

④ sowing method The appropriate density of onion seedlings for 1.5 million plants per hectare, autumn sowing seedlings should be not less than 3 million, in case of winter freeze weak seedlings and a small number of inter-seedling. Spring sowing should have 2.25 million seedlings per hectare, in order to prepare for inter-seedling and a small number of natural dead seedlings. The germination rate of green onion seed is generally not high, about 75%, according to the germination rate and seedling emergence rate calculation, fall sowing per hectare with 30-45 kg of seed, spring sowing with 15-22.5 kg of seed. Sowing is usually used for seeds without pre-sowing treatment. There are also areas where the seeds are soaked in warm broth at 50-55°C for 20-30 minutes before sowing; or the seeds are soaked in 0.2% potassium permanganate solution for 20-30 minutes, and then rinsed with clear water to kill the germs on the surface of the seeds. Seed soaking can be 1-2 days ahead of the soil. There are two methods of sowing: sowing and strip sowing. Sowing is to start a layer of fine soil as a mulch in the sowing bed first. The bed is filled with water, and then the seeds are evenly spread, and then covered with 1-1.5 centimeters of soil. In this way, the soil moisture is good, the mulch is not crusted, the mulch is even, and the seedling rate is high. When the soil moisture is good, but also can not water, the first seed, and then cover the soil, step solid. This is called dry sowing method. Strip sowing is in the bed according to about 15 cm row spacing open 1.5-2 cm deep shallow ditch, seed sowing in the ditch, cradle flat bed, tread solid.

⑤ Seedling pre-winter management 6-8 days after the fall sowing can come out full seedlings. Spring sowing earlier, due to lower temperatures, slow germination, need 15-25 days out of the soil. During this period, it is necessary to maintain sufficient soil moisture, and the ground surface is not crusted. Before the emergence of seedlings can be lightly raked once beds, in order to conserve moisture to prevent crusting. If the soil is dry, you can pour small water. If possible, cover the film after sowing to retain moisture and increase temperature, and remove it in time when the seedlings emerge. Seedling pre-winter growth period, the temperature gradually low, slow growth. At this time, water and fertilizer should be controlled to prevent seedlings from growing too large or growing too long. General pre-winter watering can be 1-2 water. Seedling flush after watering once a small water, soil freeze before watering overwintering water. Watering should be carried out according to the soil moisture, such as the soil is not dry can not water. After pouring freezing water, you can thinly spread two layers of fine horse manure, soil fertilizer or grass ash 1-2 cm thick in the nursery bed, in order to help prevent cold and moisture conservation, seedlings can safely overwinter. Covering can not be too thick, or heat rot seedlings. Onion seedlings before overwintering the normal standard is: the average plant height of about 10 centimeters, there are 2 true leaves and 1 heart leaf; seedling bulb base diameter of 0.3 centimeters or less; seedling strong and prosperous. Seedlings are too large, then the next year first draw serious phenomenon; too small is easy to freeze.

⑥ spring seedling field management When the average daily temperature reaches 13 ℃ in spring, the nursery beds covered with grass out of the beds, and then watering water. The water should not be poured too early to avoid lowering the ground temperature. When possible, combined with the watering of the green water, sprinkled with well-rotted organic fertilizer, 4500-7500 kg per hectare. Then plowing, inter-seedling, weeding. Inter-seedling, pull out the weak, dense seedlings, to maintain the seedling spacing 7-8 cm. Autumn sowing seedlings after watering the return of green water, squatting seedlings 10-15 days, so that the seedlings grow thick, for the next stage of growth to lay the foundation. After squatting seedlings into the vigorous growth period, growth accelerated significantly, to increase the number of watering, keep the soil see in see wet. At the beginning of the vigorous growth of seedlings, North China in late April to early May after the first fertilizer, onion seedlings in the middle of the vigorous growth, about the second in late May after the second fertilizer, each time per hectare of urea 100-150 kg. Chasing the first fertilizer, spraying 100 mg / kg of brassinolide Shuo Feng 481 liquid, to promote plant cell division, accelerate the rapid growth of seedlings. Spring sowing seedlings, seedling emergence to keep the soil moist, in order to facilitate the emergence of seedlings. Seedlings out of the flush watering in a timely manner, to 3 true leaves when the control of watering, to promote the development of the root system. 3 leaves after the period of sufficient water and fertilizer to accelerate seedling growth. When the green onion seedlings 50 cm high, 8-9 leaves, 10-15 days before planting, should stop watering, exercise seedlings, so that the leaves are old and healthy, pseudostem tight, in order to facilitate the transplanting of slow seedlings. Onion seedlings can be planted in an area of 5-8 hectares per hectare. Planting of strong seedling standards are: the average weight of a single plant is about 40 grams; height of about 50 centimeters; white onion length of about 25 centimeters; white onion thickness of about 1 centimeter; tubular leaf color green, not less than 5-6 pieces per plant; with the typical traits of this variety.