Reasonable irrigation is an important measure to ensure the robust growth of greenhouse vegetables and increase yield. Greenhouse vegetable irrigation depends on both the weather and the land. According to experience, the following four measures should be taken for watering vegetables in greenhouses:

  1. Shallow water and should not be too large: Under low temperature environment, the vegetables in the greenhouse evaporate slowly and the water demand decreases accordingly. Therefore, the watering amount should be small and the interval should be longer. Avoid flooding with large water. It should be watered or sprayed. To prevent low temperature and high humidity from causing the vegetable roots to rot. The first two days after watering can easily cause the humidity in the greenhouse to increase. Reasonable ventilation and cooling should be taken to prevent induced diseases. Ventilation is generally appropriate at high noon temperatures.
  2. Appropriate irrigation time: Winter greenhouse vegetable irrigation should be arranged around noon, preferably after 10 am and before 3 pm. In this period, the greenhouse temperature is high and the side effects after watering are small. Avoid watering in the morning and evening to prevent frost damage to vegetables. Irrigation should use well water as much as possible, because the temperature of the well water is high, which can reduce the physiological stimulation of vegetables.
  3. Flexible watering according to weather changes: According to the weather conditions, master the principle of “watering properly on sunny days, little or no watering on cloudy days, and no watering on snowy days”. When the weather changes from sunny to cloudy, the amount of water should gradually decrease, and the interval should be appropriately lengthened; when it changes from cloudy to sunny, the amount of water changes from small to large, and the interval time changes from long to short.
  4. The amount of watering changes according to different areas: The temperature of different parts of the greenhouse varies widely, and the amount of watering should also be different. In the southern part of the greenhouse and near heat sources such as stoves and flues, soil moisture and evaporation are large, and the amount of watering can be appropriately large. The temperature on the east and west sides of the greenhouse is lower, and the time of sunlight is short. The amount of watering should be appropriately small some.