How to ventilate the greenhouse in winter?

Reasonable ventilation in greenhouse in winter can effectively reduce the temperature and humidity, which is also directly related to the yield of crops and plays a very important role in the growth of eggplant, fruits and vegetables.

We growers all know that the crop growing environment needs suitable temperature and humidity, and the indoor harmful gas concentration is lower than the minimum limit that will harm crop growth. The basic function of greenhouse in winter is to create a controllable environment for crops, especially the reasonable and effective ventilation in greenhouse in winter.

In this regard, our growers can formulate effective management measures according to the ventilation time, ventilation volume and ventilation temperature of greenhouses in winter.

First, the main points of greenhouse ventilation in winter {1}, greenhouse ventilation time should generally be carried out when the temperature in the greenhouse is too high, the relative humidity is high, and photosynthesis is accelerated. Secondly, after watering, fertilizing or spraying pesticides, the humidity should be ventilated for a short time. When it is cloudy and sunny for a long time, the mulch outside the shed should be opened at intervals, and the air volume should be small to avoid excessive sunlight and increased transpiration, resulting in crop wilting due to water loss.

Different crops have different requirements for temperature. Usually the temperature during the day is at least 5~8 degrees higher than that at night. The temperature in the greenhouse should be adjusted according to the crop types and appropriate temperature limits.

{2}, greenhouse ventilation should adhere to the principle of from small to large, from less to more. At the same time, we should also pay attention to adjusting the local temperature difference in the shed, and the places with high temperature should be ventilated relatively early. When the temperature is low, the air is late and the air outlet is small. When closing the air outlet, it should be done step by step from big to small, from more to less.

Secondly, it is necessary to prevent cold air from blowing directly on the crops in the shed during ventilation, which will easily cause the temperature to rise and fall, and gradually make the leaves and young fruits of crops suffer from freezing damage. Greenhouse ventilation can exchange indoor air with outdoor air with low relative humidity, eliminate excess water vapor in indoor air and reduce the relative humidity of indoor air.

{3} When the temperature in the shed is higher than the temperature required for the normal growth of plants, it should be ventilated to reduce the temperature, so as to prevent the crops from catching cold or freezing due to the low indoor temperature after ventilation. Suitable temperature environment is the key to the normal growth of greenhouse crops in winter. In early winter, we should pay attention to proper ventilation and cooling, control the vigorous growth of plants and enhance the stress resistance of plants. Secondly, in winter greenhouse crop production, it is an effective measure to take various effective measures to increase the light time and intensity, which is to promote crop photosynthesis and increase vegetable yield.

In winter, the plastic film of greenhouse crops is closed, and the humidity in the greenhouse is high. Under the condition of ventilation, the air in the greenhouse is relatively humid.

The temperature is about 70%, and it can reach above 90% in rainy days or after irrigation. It is particularly important to implement artificial lighting in greenhouse during the solar term or insufficient sunshine in late winter, but it is difficult to popularize it in a large area at present because of its high cost, but it can be used as an emergency measure to improve the lighting conditions in greenhouse.

1. When the temperature in the shed is higher than the temperature required for the normal growth of plants, ventilation should be carried out to cool down. In order to prevent freezing injury or freezing injury to vegetables caused by too low indoor temperature after outdoor air. Therefore, it is particularly important for us growers to master the temperature requirements at all stages of vegetable growth and development.

2. The core of temperature management in late winter is to improve the temperature and insulation in the shed. Attention should be paid to the selection of drip-free film with good light transmittance and long service life, and the film surface should be cleaned frequently to maintain high light transmittance of greenhouse film. Under the premise of keeping the temperature in the greenhouse unchanged, try to uncover the lid as soon as possible, so that the vegetables in the greenhouse can see more light as soon as possible, so as to increase the accumulation of photosynthetic products. On cloudy days, as long as it doesn't rain or snow, it is necessary to pull the awning or pull the awning at regular intervals to increase the scattered light and maintain the normal photosynthesis of plants.

3. Ventilation promotes the exchange of high humidity air in the shed with low humidity air outside, which can effectively reduce the relative humidity in the shed. Liu Fang personally suggested that spraying powder, spreading pesticide soil and smoking can not only control pests and diseases, but also effectively control soil and air humidity.

Due to the sealing effect, the carbon dioxide content in the air in the greenhouse is usually very low during the day. Reasonable application of carbon dioxide can improve crop photosynthesis, accelerate crop growth and increase production and income.

In winter, the heat preservation and ventilation of greenhouse have an important influence on the cultivation of crops in greenhouse. It is inefficient and unscientific to manage greenhouses only by manpower, and there are also great hidden dangers in certain safety. Liu Fang suggested that equipment can be used to effectively reduce the planting burden and reduce human labor. Only scientific planting and effective management can maximize the benefits of crops, and it is also an important measure for effective ventilation in greenhouses in winter.