Is the cold spring coming? The temperature in some areas has dropped by 20 degrees, and there will be heavy snowstorms in many places. How cold is it? It&;s almost halfway through spring, and it&;s already raining lightly in some areas, like the weather in North China, which still feels wet and cold. &”;Spring rain in MengMeng is as expensive as oil, and it is sprinkled on farmland and flows all over the street. Grass, willows and green bamboo shoots are in their early stages, and the weather is good every year.&”; This ancient poem describes the drizzle in spring as valuable as oil. Since March, the weather in the south of the Yangtze River has been hot, especially the temperature in Anhui is as high as 27℃, and the temperature in Chongqing has been as high as 30.5℃. This is not spring, but obviously summer. However, families should pay attention to the fact that after a relatively warm late winter and early spring, the heat accumulated in the atmosphere meets the cold air from the north, and when these two forces confront each other, it is easy to produce extreme strong convective weather. No, according to the weather forecast, a wave of cold air has hit Jiangsu, Zhejiang and Shanghai since March 14th. From the satellite cloud picture, we can also clearly see the dust belt in the middle of Jiangsu and the Yellow Sea and the dense hail cloud system in Anhui and Zhejiang. Local farmers should take preventive measures in advance. Snowfall weather occurred in the north due to the influence of low temperature, especially in Jilin and Heilongjiang. This cold air did not stay too long. On March 18th, it penetrated into North China, and by March 18th, most parts of the country began to cool down rapidly. How cold is it? According to the weather forecast, this wave of cold air will lead to cooling in many places and accompanied by rain and snow. The cumulative cooling range in many places will reach more than 10 C, and some areas will even approach 20 C. Overall, the body feel is still relatively cold. For example, in Zhengzhou, Henan Province, the highest temperature was still at 25℃ on March 15th, but on March 17th, the temperature dropped directly to about 5℃, with a drop of about 20℃. This temperature, which is high first and then low, is not good for local crops such as wheat and garlic. Farmers should take preventive measures to prevent crops from freezing injury by watering low-moisture plots or spraying antifreeze. This wave of cooling is not only cold in Northeast China and North China, but also in the south. For example, the temperature in Changsha, Hunan Province was still 30℃ on March 15th, but the temperature had dropped to around 10℃ on March 21st due to the continuous influence of cold air, and the cumulative cooling rate was not small. Affected by this wave of cold air, there will be a wave of snowfall from March 16th to 17th. Snowfall areas are concentrated in parts of northern Qinghai, Hexi, Gansu, northern and western North China. It is mainly light to medium snow or sleet. However, according to the forecast, there will be snowstorm weather in Xinjiang along the Tianshan Mountains, central Inner Mongolia and parts of northern North China, which will bring challenges to local crop growth. Due to the influence of cold air, there is snowfall in the north and rainfall in the south. This wave of rainfall is mainly concentrated in the Yangtze River basin in China, and there will be a moderate to heavy rainfall process. Among them, there are heavy rains in Hunan, Hubei, Anhui and other regions. By the 20th-22nd of this month, the precipitation cooling is mainly concentrated in the south of the Yellow River in central and eastern China and some areas in the middle and lower reaches of the Yangtze River, and there will be a process from moderate to heavy rain to heavy rain. With the continuous precipitation and cooling, it may lead to late spring chill in some areas.The situation, in any case, the trend of cooling and wet cooling is set, and farmers&; friends should take precautions. With the invasion of this cold air, it can still have an impact on northern wheat and southern rapeseed. At present, the winter wheat in North China has turned green in an all-round way and is about to enter the jointing stage. In addition, rape and fruit trees have also entered the flowering period, and vegetables have also entered the period of large-scale seedling raising and transplanting, and their cold resistance has decreased and they are vulnerable to freezing injury. Farmers&; friends should spray antifreeze before the low temperature comes, so as to avoid freezing injury and reduce production! For wheat crops, we can spray potassium dihydrogen phosphate fulvic acid or alginic acid to enhance the frost resistance before the low temperature comes. You can also choose potassium dihydrogen phosphate brassinolide urea, which can not only promote growth but also enhance frost resistance. Wheat has two tillering stages, one before the year and one after the year. Because the temperature in early March was higher than that in previous years, wheat jointing was advanced, and this time there was a sharp drop in temperature in North China and other places, which would lead to freezing injury of wheat at jointing stage. Even if there is freezing injury, farmers&; friends don&;t have to worry too much. Because, it is impossible for all tillering wheat to freeze to death, and high tillering buds can still develop into ears. After low temperature, we should take remedial measures in time to ensure the yield. When the low temperature comes, we should go to the field to observe at any time. When we find that the leaves of wheat are frozen at jointing stage or the freezing rate of young ears of main stems is less than 10%, we can slowly adjust the wheat itself without taking any measures, and the yield will not be affected. However, when we find that the freezing rate of wheat in the field is between 10% and 30%, we can appropriately topdressing some urea to promote growth, and topdressing about 10 kg per mu can meet the demand. If it is found that the freezing death rate of wheat leaves and main stems reaches 30%-50%, it is recommended to topdressing 15-20 kg urea per mu; If the freeze-death rate is above 50%, the use of urea will increase. It is recommended to topdressing 25-30 kg urea per mu. Wheat is damaged by freezing around booting stage, so it is suggested to topdressing 6-8 kg urea per mu, or spraying 50 kg urea, 750 g potassium dihydrogen phosphate and 150-200 g brassinolide on leaves per mu, which is beneficial to increase the number of grains per panicle and increase the grain weight. However, this year&;s urea is still very expensive. At present, we buy a bag of urea from the dealer at a price of almost 140-150 yuan. Later, we need to topdressing jointing and booting fertilizer, and the investment has increased a lot. In addition, wheat is more vulnerable to pests and diseases after freezing injury, so we should pay attention to monitoring and do a good job in pest control, especially wheat scab, which will come menacingly every April, so we should take precautions in advance! The full text is over, please help forward it and help more farmers! Thank you very much.