Adverse and beneficial effects of cold wave on agricultural production

The favorable influence of cold wave on agricultural production: geographers' research and analysis show that cold wave contributes to heat exchange on the earth's surface. With the increase of latitude, the energy received by the earth from solar radiation gradually weakened, so the earth formed tropical, temperate and cold zones. The cold wave injects a lot of cold air into tropical areas, which makes large-scale heat exchange on the ground, which is very helpful to maintain the ecological balance of nature and maintain the lush species. Meteorologists believe that the cold wave is the guarantee of good weather. China is affected by monsoon, and its winter climate is dry, which belongs to dry season. However, whenever the cold wave invades the south, it will often bring a wide range of rain and snow weather, alleviate the winter drought and benefit crops. Why can the agricultural proverb "Xue Ruizhao has a good year" be circulated among the people for generations? This is because snow water has a high nitrogen content, which is more than five times that of ordinary water, and can greatly increase the nitrogen in the soil. Snow water can also accelerate the decomposition of soil organic matter, thus increasing the organic fertilizer in the soil. The heavy snow covered the overwintering crops and played the role of a quilt, keeping out the cold and keeping warm. There is a saying that "winter is not cold, and the coming year is not abundant", which also has its scientific truth. Experts in crop pest control believe that the low temperature brought by the cold wave is the most effective natural "insecticide" at present, which can kill a large number of pests and germs lurking in the soil for the winter, or inhibit their reproduction and reduce pests and diseases in the coming year. According to the survey data of agricultural technology stations around the country, pesticides can be saved by more than 60% in the year of heavy snow and winter closure. Adverse effects of cold wave on agricultural production: An obvious feature of cold wave weather is the drastic cooling. Low temperature will lead to freezing injury of crops, freezing injury of rivers and ports, traffic interruption, and often bring economic losses to industry and agriculture. Cold wave freezing injury refers to the freezing injury of winter cold to overwintering crops. The cold wave weather process is a weather process in which a large range of strong cold air moves south in high latitudes, causing severe cooling and strong winds in its path. When the temperature drops below 0℃ (freezing point) or remains below 0℃ for a long time, the plants of overwintering crops will be frozen and lose all physiological activities, leading to plant withering or death. Severe low temperature will also cause livestock to get sick or freeze to death, which will lead to serious meteorological disasters in agriculture and animal husbandry, that is, cold wave freezing injury. Cold wave freezing injury is mainly caused by low temperature freezing injury to plant tissues below 0℃ (freezing point). Many research results show that the freezing of cells and tissues caused by low temperature is the cause of plant death.