White Dew

White Dew

Bailu is the 15th solar term in the 24 solar terms, and also the third solar term in autumn. It indicates the end of mengqiu and the beginning of mid autumn. It is an important season reflecting the temperature changes in nature. Bailu is the end of Shenyue and the beginning of youyue in Ganzhi calendar. The time point is from September 7 to 9 in Gregorian calendar, when the sun reaches 165 degrees of yellow longitude.

Bailu is the solar term with the largest temperature difference between day and night. Before and after Bailu, the residual summer air gradually disappears, the Yin air of heaven and earth rises and diffuses, and the weather gradually turns cool. The dew in the morning thickens day by day and condenses into a layer of white water droplets on the grass leaves. The ancients used four seasons to match five elements. Autumn is golden and white, so it is called Bailu.

According to the observation of nature, the ancient Chinese divided Bailu into three periods: "one is when the wild geese come, the second is when the Xuanniao return, and the third is when the birds raise shame." This means that in this solar term, the migratory birds such as wild geese and swallows fly south to avoid the cold, and the hundred birds begin to store dried fruits for the winter. At present, farmers are also busy harvesting crops, just as the so-called "grab autumn, grab autumn, do not grab lost.". During the Bailu period, the local folk customs mainly include sacrificing to Dayu, brewing grain wine, drinking Bailu tea and so on.

historical origin

The origin of the name

According to the interpretation of "Bailu" in the collection of seventy two lunar orders, "water and moisture condense into dew, autumn is golden, golden and white, white is the color of dew, and Qi begins to be cold.".

According to the almanac, "Dou Zhi GUI is Bailu, Yin Qi is getting heavier, Ling is dew, so it's called Bailu.". As the weather gradually turns cool, the sun is still hot in the daytime, and the sun returns to the mountain, the temperature will soon drop. At night, the water vapor in the air will condense into small drops, which are very closely attached to the green stems and leaves or petals of flowers and trees, and appear white. Especially in the morning, it looks more crystal clear, pure and white, which is very popular, so it is called "White Dew" It's a good name.

Astronomical calendar

Bailu is the beginning of the first month of the Ganzhi calendar, the 24 solar terms and the establishment of December are the basic contents of the Ganzhi calendar, and the establishment of you in August. In ancient times, the order of the moon was calculated by the operation of the Big Dipper. The time referred to by the dipper was called "Doujian" (also known as Yuejian). Such as "Huainanzi astronomy training" included: "emperor Zhang Siwei, transport to fight, on the move of one hour, return to its place, the first month refers to Yin, December refers to ugly, one year old and turn, and all over again.". Here "dou" refers to the handle of the Big Dipper. The bucket handle rotates clockwise for one cycle, which is called one of the "year" (photo). "Construction in December" is based on the "24 solar terms". The division of "construction in December" is based on the seasons, that is, the beginning of spring, Jingzhe, Qingming, Lixia, mangzhong, Xiaoshu, Liqiu, Bailu, Hanlu, Lidong, Daxue and Xiaohan, respectively as Yinyue (shetige), maoyue (danyao), Chenyue (Zhixu), Siyue (dahuanluo) and noon Yue (dunyao) ）It is the beginning of Weiyue (xieqia), Shenyue (Xietan), youyue (zuogu), Xuyue (Weimao), Haiyue (dayuanxian), ziyue (Kuitun) and chouyue (chifenruo).

Bailu is the end of Shenyue of Ganzhi calendar and the beginning of youyue. The time point is from September 7 to 9 of Gregorian calendar, when the sun reaches 165 degrees of yellow longitude.

Climate change

Since the beginning of Bailu, the summer monsoon is gradually taken over by the winter monsoon, and the cold air moves southward more frequently. In addition, the position of the sun directly on the ground moves southward, so the sunshine time in the northern hemisphere becomes shorter, the sunshine intensity weakens, the night is often sunny and cloudless, and the ground radiates and dissipates heat quickly. Therefore, the temperature drop is also gradually accelerated. There is a saying that "Bailu autumn night, a cool night". From the Bailu solar term, according to the standard of climatology, all regions began to enter autumn. At this time, the temperature difference between day and night in China can reach 8 ℃ - 16 ℃, so Bailu is also the solar term with the largest temperature difference in a year.

At this time, the middle and lower reaches of the Yangtze River are prone to heavy rain or low temperature and continuous rain. According to the folk custom, it is a bad sign of rain on the Bailu Festival. Therefore, there is a saying that it is rain before the Bailu Festival and a ghost after the Bailu Festival. Dew is a major feature of Bailu Festival. The appearance of dew marks that the weather has turned cold and the weather has passed. The scorching sun turns into rain. Bailu spent the night with autumn wind. It is cold and cold all night.

Phenological phenomenon

overview

During the Bailu solar term, the summer air gradually subsided, the autumn air was crisp, the fragrance of Osmanthus fragrans, the migratory birds such as wild geese and swallows began to fly south to avoid the cold, and all kinds of birds began to store food for the winter.

"When the wild goose comes, the black bird returns." After Bailu, the most sensitive migratory birds to climate migrate. The wild geese began to fly from the north to the south, and the southern Xuanniao also flew back to the north, and all kinds of birds began to store food for the winter. As a folk saying goes, "the wild geese fly to the south in the autumn night with Bailu," and "in the early autumn, the cicada wakes people to sleep, the sunflower smiles in the summer, the wild geese come back with Bailu and Yan, and the osmanthus fragrance fills the garden at the autumnal equinox.". Therefore, migratory birds such as geese are regarded as a symbol of autumn.

Bailu sanhou

Wait for the wild goose to come. Hong is big and Yan is small. They are two different kinds. Geese fly north in February and South in August.

Wait for Xuanniao to return. Xuanniao is a swallow. Swallows come from the spring equinox and leave from the autumn equinox. It is a bird of the north. Flying south brings vitality. Now fly north to return, half of the red flowers fall, Yan return, autumn wind bleak, white dew to the mountain leaves fly down. "Yueling 72 Hou Ji Jie" says: "Xuanniao Jie sees the equinox (at the beginning of the equinox, Xuanniao arrives; Yanlai also comes). At this time, it moves from the north to the south. Yan is a bird of the south, so it is called GUI."

Three wait for birds to raise shame. This "shame" is the same as "food", which is a delicacy. "Xuanwu hides the shade of wood, while danniao raises shame". Raising shame refers to that birds sense the spirit of extermination and store food one after another for winter, such as Tibetan delicacies. "Yizhoushu · Shixun:" on the day of Bailu, the wild geese come, and on the fifth day the mysterious birds return, and on the fifth day the birds raise shame

Farming activities

Bailu season is a busy season in China. In Northeast China, millet, sorghum and soybean are harvested, and new cotton is picked in some places. At the same time, seed selection and seed reservation for cotton, corn, sorghum, millet and soybean should be carried out, and stubble, soil preparation and fertilizer delivery should be carried out in time to rush wheat planting. In North China, it is also a busy autumn harvest season. All kinds of autumn crops are mature and begin to harvest. At the same time of autumn harvest, we have to pay close attention to sending manure, ploughing and leveling the land, so as to make preparations for planting wheat as soon as possible. Winter wheat was sown in Northwest China. When it comes to the White Dew season in Southwest China, there is a busy scene everywhere, because "the White Dew is boundless, the millet is full of yellow, and the rice and millet have to seize the time to harvest. Late autumn crops such as corn and sweet potato should strengthen field management to promote their early maturity and avoid damage caused by low temperature and frost. In Central China, we should seize the time to harvest late and mid season rice, harvest summer corn, harvest cotton in batches, and strengthen water management for late corn. In addition, we have to seize the time to level up the land and prepare for wheat planting.

After the Bailu solar term, the cold air becomes more and more active, and the low temperature weather often occurs, which affects the heading and flowering of late rice. Huang Huai, Jiang Huai and South China should seize the favorable opportunity of higher temperature to irrigate shallow water frequently. During the period of Bailu, the sunshine in South China is less than that in summer, and the rainfall is more, which has the characteristics of small intensity, more rainy days and continuous. Therefore, there is a saying in the agricultural proverb that "Bailu weather is fine, and the rice is as white as silver". In this regard, we should take corresponding agricultural measures to reduce or avoid the harm of autumn rain, and pay attention to the prevention and control of rice blast, Sclerotinia and other diseases.

traditional custom

Collect the clear dew

In the Ming Dynasty, Li Shizhen recorded in the compendium of materia medica: "when autumn dew is plentiful, it is collected on a plate and fried like malt, which makes people not hungry." "The autumn dew on the head of a hundred grasses is collected before sighing. The more sick they are, the less thirsty they are. It makes the body light, not hungry, and the muscles happy." "Flowers on the dew, a good color.". Therefore, receiving the pure dew has become the most special "ritual" of Bailu.

Drink Bailu tea

Bailu tea is a kind of tea picked in Bailu season. There is a saying among the people that "spring tea is bitter, summer tea is astringent, you need to drink tea, and autumn Bailu tea". At this time, after the summer heat, Bailu tea is another good growing season. Bailu tea is neither as fresh and tender as spring tea, nor as dry and bitter as summer tea. It has more excessive flavor and gives people just the right feeling. Take a sip, the taste between lips and teeth is full of mellow, loved by old tea guests.

Eat sweet potatoes

Sweet potato is rich in protein, starch, pectin, cellulose, amino acids, vitamins and a variety of minerals, with sugar content of 15% - 20%. It has anti-cancer, heart protection, prevention of emphysema, diabetes, weight loss and other effects. Traditional Chinese medicine regards sweet potato as a good medicine and has the reputation of "longevity food". According to Li Shizhen's Compendium of Materia Medica, sweet potato can tonify deficiency, invigorate spleen and appetizer, and strengthen kidney yin. It is believed that eating sweet potato in Bailu can prevent the stomach from getting sour after meals, so farmers used to eat sweet potato in Bailu Festival.

Sipping rice wine

There has always been wine making custom in Xingning, Sandu and liaojiang areas of Zixing, Hunan Province. Every year, when the Bailu Festival comes, every family will drink "local wine" when they receive guests. The wine is brewed from glutinous rice, sorghum and other grains. It is warm and slightly sweet. It is called Bailu rice wine.

Jiangsu and Zhejiang also have the custom of brewing Bailu rice wine. In the old days, when Bailu came to the countryside in Jiangsu and Zhejiang provinces every year, every family made wine to entertain guests, and some people often brought Bailu rice wine to the city. Until the 1930s and 1940s, there were still handmade Bailu rice wine in hotels in Nanjing, which gradually disappeared.

Sacrifice to King Yu

People living on the Bank of Taihu Lake in Jiangsu Province will offer sacrifices to King Yu during the Bailu season. King Yu is the legendary hero of flood control. Fishermen along Taihu Lake call him "water Bodhisattva". Every year on the eighth day of the first month, Qingming Festival, the seventh day of July and Bailu Festival, there will be a incense festival for King Yu, among which Qingming Festival and Bailu spring and Autumn Festival are the largest, lasting for one week.

Eat longan

There is a traditional custom in Fuzhou, Fujian called "Bailu must eat longan". Folk meaning

Chinese PinYin : Bai Lu