Great cold in the twenty-four solar terms

Like slight cold, great cold is also a solar term representing the degree of cold weather. Although many records of modern meteorological observation show that in most parts of China, the severe cold is not as good as the slight cold, in some years and a few coastal areas, the annual minimum temperature will still appear in the severe cold solar terms. In the severe cold season, the average temperature in our basin is mostly 6℃ to 8℃, which is nearly 65438 0℃ higher than that in the slight cold season. The proverb "slight cold and severe cold, cold into a ball" shows that the severe cold solar term is also a cold period of the year. Therefore, it is necessary to continue to do a good job in the cold protection of crops, especially to protect livestock from wintering.

For some crops, a proper low temperature is necessary in a certain growth period. Wheat and rape with strong winterness need lower temperature through vernalization stage, otherwise they cannot grow and develop normally. Winter in the basin of our province is warm all the year round, and wheat and rape sown too early often grow too vigorously, jointing and bolting ahead of time, which greatly weakens the cold resistance and is vulnerable to low temperature frost. It can be seen that selecting crop varieties according to local conditions, sowing and planting in time and taking effective measures to promote and control are important links to win high yield.

Slight cold and severe cold are the periods with the least rainfall in a year. In the cold season all the year round, the rainfall in our province only increased slightly compared with the previous period, with 5 ~ 10 mm in most areas of the basin and only 1 ~ 5 mm in the mountainous areas of western Sichuan Plateau. Although there is little difference in rainfall between the east and the west of the province, it is dense and foggy in the east and sunny in the west, and the weather is very different. During the drought in winter and the overwintering in the basin, the water consumption is small, and the contradiction between supply and demand of farmland water is generally not prominent. However, "don't complain about the rain and snow when you are bitter and cold. The snow will be reserved for next year's wheat." In the case of scarce rain and snow, it is undoubtedly beneficial to the growth of early spring crops to water in different areas according to different farming habits and conditions.