The sudden drop in temperature, how can greenhouse vegetables survive winter?
Recently, the long-awaited northern region ushered in rain and snow, and the sudden drop in temperature made people think that winter really came. According to the forecast of the National Meteorological Observatory, the maximum temperature in some areas of Hebei and Shandong was only 3°C, and the minimum temperature suddenly dropped to -7°C or even lower. With the changes in the weather and the arrival of strong winds to cool the weather, vegetables in winter greenhouses are also experiencing the test of severe cold. Over the past few days, we have been receiving phone calls from a number of vegetable farmers. The most inquired question is how the winter greenhouses can be better protected against freezing and how to prevent greenhouse vegetables from freezing in cold weather. Based on the experience and lessons of the past few years, we have summarized the experiences of insulation and antifreeze of winter greenhouses for the reference of farmers. 1. Carefully check the looseness of the greenhouse and take reinforcement measures. Cooling rain and snow are often accompanied by strong winds. When encountering windy and snowfall conditions, check carefully where the greenhouse is loose and take reinforcement measures. Such as the reinforcement of the lamination line, the south end of the lamination line is fixed on the underground anchor, the north end is tied with a stone or sandbag, and is fixed outside the north wall, and the elasticity of the lamination line is adjusted at any time. Damaged parts of the plastic film should be promptly repaired to prevent the snow from blowing into the shed. 2. Timely warming. To cool the weather, cover in advance in the afternoon and maintain the tightness of the shed film. In rain and snow, a layer of shed film should be put on the insulation and grasshoppers to prevent the rain and snow from wetting the quilts and grasshoppers. The old shed wall has poor thermal insulation properties, and it can be stacked with straw or crop stalks at the bottom of the back wall of the greenhouse to form wind barriers to block wind and cold. 3. Remove snow from the shed in time. In rain and snow, the snow on the shed should be removed in time to prevent the snow from falling from the scaffold and collapse the shelter. Clear trench drainage work on both sides of the greenhouse in time, and timely clean up when snow accumulates. 4. Temporary warming. When the daytime temperature in the greenhouse is lower than 15°C and the nighttime temperature is lower than 5°C, cold or freezing injury may occur. Temporary warming measures should be taken at night to artificially supplement heat energy. Several briquettes can be placed in the shed to increase the temperature inside the shed. However, attention should be paid to preventing carbon dioxide poisoning, and greenhouses should be ventilated before entering people. 5. Take a small water pouring, under the film dark irrigation method. In winter, not only the temperature is low, but also the ground temperature is low. For example, excessive watering causes the ground temperature to drop. Second, it causes poor ventilation in the soil and directly affects the activity and absorption of vegetable roots. The use of small drip irrigation under the membrane can meet the vegetable's need for water without excessively reducing the temperature of the ground. In order to increase the ground temperature, corn stalks and the like can be laid on the walkways, which can protect the ground temperature, reduce the air humidity in the shed, and facilitate the growth of the roots of vegetables. 6. More light ventilation. In the event of continuous rain and cool weather, it is not possible to cover the straw or thermal insulation in the daytime to keep the vegetables in a dark environment. Clean up the sand and dust on the greenhouse film after sunny days. Do not water or spray pesticides on cloudy days. In the days of cool and cloudy days, due to the lack of light, the dark environment of the day will cause yellowing of vegetables. In order to increase the light, the straw curtain should be opened every day and the reflective film should be hung on the wall in the north of the greenhouse (see the figure). 4) Let the vegetables receive scattered light to maintain the formation of chlorophyll. 7. Master fertilization techniques. Avoid excessive application of high-nitrogen and potassium fertilizers during cooling period. Special precautions must be made to use potassium nitrate and other types of fertilization with caution. Appropriately supplement microbe and fish protein organic fertilizers and foliar spray Pideline fish protein and potassium dihydrogen phosphate. It can increase the resistance of crops and increase the cold and frost resistance of plants. LED Waterproof fittings,waterproof bathroom light fitting,waterproof lamp holder,IP65 Waterproof Fittings Ningbo Wellway Optoelectronic Technology Co.,Ltd , https://www.wellwayopto.com