What are the misunderstandings of greenhouse ventilation in promoting greenhouse production?

Only when the greenhouse is exposed to the right wind will the output increase. There are several misunderstandings in exposure. Be sure to determine the size of the wind according to the wind direction. When the west wind blows or the west wind blows, the wind will enter the shed along the air outlet, resulting in a lower temperature at the east end of the shed. Vegetable farmers can properly close the air outlet at the east end and put it at the west end of the greenhouse. On the contrary, the same management measures should be taken in case of easterly winds or easterly winds. When there is a south wind or a north wind, the air outlets on the east and west sides of the greenhouse can be opened as wide as possible.

Be sure to let the wind out step by step, and don't hang the whole shed directly. In autumn and winter, don't let the air out for one hour after opening the quilt in the morning. The respiration of plants overnight will produce a lot of carbon dioxide for photosynthesis the next day. It is an important raw material, so this time is an important period for plants to store nutrients. After one hour, let the air out for 7-8 minutes. A five-centimeter mouth is enough to put in carbon dioxide to remove water. When the temperature reaches the temperature, the upper limit of the temperature is to release air again to reduce the temperature and eliminate moisture.

There are also many vegetable farmers who believe that the purpose of building greenhouses is to keep warm, which is also the most fundamental reason for vegetable farmers to build greenhouses. Vegetables grow rapidly at high temperature. In fact, vegetables have an upper temperature limit. After watering the shed in winter, the ground temperature in the shed dropped obviously. If you ventilate after watering, the temperature in the shed will always be kept at a low level, and the ground temperature will naturally not rise. Long-term exposure of roots to low ground temperature is easy to damage roots, resulting in weak water and fertilizer absorption capacity and hindering the growth and development of vegetables. It is not advisable to ventilate for a long time after watering, and the water in the shed cannot be discharged, which is beneficial to the infection of pathogenic bacteria.

Outdoor air must be combined with the weather forecast of the day. Not ventilating too early on cloudy days will only reduce the temperature of the greenhouse. If the temperature cannot be guaranteed, forced ventilation and dehumidification will cause freezing damage to vegetables. Generally, greenhouses are only used in winter, so outdoor air is the most important in winter. Outdoor air is effective when it is warm at noon, and it is generally not recommended in cold or windy weather.