Why leek is more suitable for facility production?

Long ago, leeks were planted in warm pits and other protected areas. Up to now, leek has become one of the three major vegetables cultivated in protected areas in China. Planting leeks in various protected areas can not only make farmers get more economic income, but also make consumers eat more leeks with richer colors, longer time and better quality. This is determined by the inherent physiological characteristics of leek. Leek is a vegetable that grows all year round. Its roots and bulbs have the function of storing nutrients. Nutrients made from leaves and absorbed by roots are not only used for current plant growth, but also transported and stored in roots and bulbs for plant growth after harvest, so leeks can be produced all year round. When the low temperature comes in winter, leeks will gradually enter a dormant state in the open field, but in the protected field, leeks can continue to grow because of the temperature and humidity conditions, thus making full use of the land, light, heat and water resources in winter. In addition, leek is a cold-tolerant vegetable, and the suitable temperature range for stem and leaf growth is 12 ~ 24℃. This temperature condition lasts for a short time in many areas of the open field and is not suitable for stem and leaf growth in summer. Therefore, the total output level of leek in the open field is low. Under the condition of protected land, when the local temperature rises to 2 ~ 3℃, the aboveground parts of leek begin to grow. When the temperature is lower than 10℃, the growth is slow, but the leaves are rich and the mesophyll is thick. When it reaches 12 ~ 24℃, the photosynthesis is strong, the products are abundant, the growth is vigorous and the yield is high. When leek is cultivated in protected field, the temperature can be raised by artificial heat preservation at low temperature, and lowered by artificial ventilation at high temperature, which is easy to keep the indoor temperature in the range suitable for leek growth. Leek also needs high humidity to grow vigorously, which generally requires air humidity of 60% ~ 70% and soil humidity of 80% ~ 85%. The protected area is relatively closed and has good moisturizing effect, which is very suitable for the physiological needs of leeks. However, diseases such as gray mold and epidemic caused by excessive humidity often appear in protected cultivation. Therefore, dehumidification measures should be taken in combination with temperature management. Chinese chives have strong adaptability to light, and can grow in both strong and weak light. However, if the light is too strong, just like the sunshine in the open field in summer, the growth rate of leek will slow down, the crude fiber content will increase, the leaves will become hard and the quality will decrease, which will become the so-called "smelly leek". The plastic film in the protected area can filter out some ultraviolet rays and weaken the light intensity, which is just suitable for the light demand of leeks. The stems and leaves are fresh and tender with excellent quality. Even in weak light or shade, leek can be softened and cultivated by relying on sufficient storage nutrition in roots.

To sum up, protected cultivation of leeks not only has high yield, but also good quality, which can fill the off-season of vegetables and enrich the vegetable baskets of residents on traditional festivals such as New Year's Day and Spring Festival, and farmers can also obtain higher economic benefits.