What is the solar term in Xiao Man?

Xiaoman, the eighth of the 24 solar terms, is also the second solar term in summer. Xiaoman, battle nail, the sun reaches 60 degrees of the yellow meridian and is celebrated every year on May 20-22 of the Gregorian calendar. The name Xiaoman has two meanings.

First, it is related to climate and precipitation. During the small solar term, heavy rains in the south began to increase and precipitation was frequent. There is a folk saying that "the river is small and full, and the river is full". The "fullness" in Xiaomanli refers to the excess rain.

The second is related to agricultural wheat. The northern region is full of solar terms and little or no rain. This "fullness" does not refer to precipitation, but to the fullness of wheat.

During the Xiaoman solar term, there is usually more rainfall in southern China, and the warm and humid airflow from the ocean is active and meets the cold air from the north to the south. At this time, there will often be continuous and large-scale heavy precipitation in South China, causing heavy rain or heavy rain, and rivers and lakes are often densely covered in South China.

If there is little rain at this stage, it may be that the Pacific subtropical high is weak and located in the south, which means that it is Huangmei season. In the north, there is little or no rain in the solar terms, during which the temperature rises rapidly and the temperature difference with the south further narrows.

Phenological phenomenon

The grain of northern wheat began to fill, but it was not completely full. Due to the differences in climate and phenology between the north and the south of China, the maturity, maturity and harvest time of wheat will be different. Generally speaking, wheat in some parts of southern China has been harvested in long summer and small harvest.

Wheat in some parts of northern China began to mature and harvest in the awning season, and wheat crops in northern China entered the filling stage in Xiao Man season, and the seeds gradually became full.

Wu Cheng, a scholar in Yuan Dynasty, edited Twenty-four Solar Terms. He divided the 24 solar terms of a year into "seventy-two periods", and each solar term was divided into three periods, of which the third period of Xiaoman was: "Waiting for the bitter vegetable show, waiting for the grass to wither, waiting for the wheat to arrive."

In other words, after the full solar terms, bitter vegetables have been flourishing. After that, some soft grasses in Yin Xi began to die in the strong sunlight, and in the last period of Xiaoman, wheat began to mature.

The third period was originally written about the summer solstice, and later some works were changed to the winter solstice of wheat. Although it is still summer, it is a mature "autumn" for wheat. Summer is the season when winter wheat ripens in the north, and autumn is the season when grain ripens, so the ancients extended the term early summer to wheat autumn (the season when wheat ripens). ?

Reference to the above content: Baidu Encyclopedia-Xiaoman