What are the environmental changes in the long summer?

One of the long summers in 24 solar terms is the long summer solar term when the sun reaches 45 on May 5th or 6th every year. China has been used to long summer as the day of long summer since ancient times. Astronomically, Chang Xia said that bidding farewell to spring is the beginning of summer. When the temperature rises obviously, the summer heat approaches, thunderstorms increase, and crops enter the peak season, people are used to treating long summer as an important solar term.

The long summer solar term was established at the end of the Warring States period (239 BC), indicating the change of seasons, and it was the day when the four seasons were divided into summers according to the lunar calendar in ancient times. & gt After the long summer, it is the critical period of water demand for large-scale cultivation of mid-season rice in South China. The early and late arrival of rainstorm and the amount of rainfall are closely related to agricultural production. At this time, if there is no heavy rain, those farmland without water irrigation can't rake pears and sow seeds. According to the statistics of climate data, the average rainstorm for many years in eastern South China began in the middle and late April, in central China in the middle and late May, and in western China in the late May. The rainfall in May is 100-200mm in the southeast of South China and 75- 100m in the northwest. Summer drought often occurs in the western and central parts of South China, because the rainstorm starts late and the rainfall is low.

In the meantime, just as southern China is harvesting spring crops and planting Da Chun crops, we should pay special attention to the influence of changeable weather. Harvest in time in sunny days and sow in rainy days. Even in rainy days, the harvest in Koharu should be protected from germination, mildew and drought, and the harm of low temperature below 20℃ to early rice should be prevented.