Will "Xiaoxue" snow? | Folk Calendar Twenty-four solar terms

Cover journalist Qin Zhou
"There is a light snow all over the sky, and the coming year will be rich." On November 22 nd, the light snow in the 24 solar terms was ushered in.
"twenty-four solar term" said: "In mid-October, the rain was thin by the cold, so it condensed into snow. The words of the little ones are not prosperous. " Will it snow with light snow? Not necessarily. As a solar term reflecting climate phenomena such as precipitation and temperature, the light snow solar term is not necessarily related to the light snow in the weather.
What are the characteristics of the climate when entering the light snow solar term? The third stage of light snow: the rainbow disappears, the weather rises, the atmosphere drops, and the occlusion becomes winter. What is the meaning behind it? "There is light snow all over the sky, and there will be a bumper year in the coming year." Is there any meteorological principle behind this agricultural proverb? Let’s listen to Wang Liwei, a lecturer in the Department of Atmospheric Science, College of Agriculture, Shenyang Agricultural University, and explain it for you.
The plants were frosted. According to Xinhuanet
Is it sure to snow with light snow?
Light snow is the 20th solar term among the 24 solar terms and the 2nd solar term in winter, which falls on November 22nd or 23rd of the Gregorian calendar every year. Light snow, like rain and Grain Rain, is a solar term reflecting precipitation. Will there be some light snow on the day of the light snow solar term? Not really.
Wang Liwei, a lecturer in the Department of Atmospheric Science at the Agricultural College of Shenyang Agricultural University, explained that it is called "light snow" because "snow" here means cold, with emphasis on "small", which means it is not too cold now, even if it snows, it will not be too big. The meaning of "light snow" in the light snow solar term is different from that in the daily weather forecast. The light snow solar term is a climate concept, and the light snow in the weather forecast refers to the snow with less snowfall intensity.
During the light snow solar term, the temperature in the northern region began to drop to below zero, snow began to fall in North China, and frozen soil began to appear in Northeast China. Although there is no snowfall in the south, except for Lingnan and some coastal areas, most cities have entered winter and the weather is getting colder and colder.
Light snow three wait:
When the rainbow disappears, the weather rises, the atmosphere drops, and the occlusion becomes winter.
Phenology refers to the periodic natural phenomena such as animals, plants, birds and weather that change with the seasons. From the phenological phenomenon, the ancients divided the light snow solar terms into three periods: one is that the rainbow disappears; Second, the weather rises and the atmosphere drops; The third weather is blocked and becomes winter.
Wang Liwei introduced that once the rainbow disappeared, he said that it was no longer raining in the northern region, and it was naturally difficult to find the rainbow after the rain. Because the rainbow is formed by sunlight shining on the spherical water droplets in the air and the light is refracted and reflected. The light snow is very cold, even if there are small water droplets in the sky, they are frozen into small ice crystals or small snowflakes, so naturally it is impossible to refract and reflect the rainbow.
The ancients regarded weather and local atmosphere as important phenology to feel the phenomenon, indicating that heaven and earth can’t communicate at this time. "When the weather rises in the second season, the earth’s atmosphere drops" and "When the weather closes in the third season, it becomes winter", which means that the yang in the sky rises and the yin in the ground drops, resulting in the disharmony between Yin and Yang and the impassability between heaven and earth. It is precisely because Yin and Yang don’t meet, heaven and earth don’t connect, everything in nature drifts and loses its vitality, and trees wither, so that it is blocked into winter, that is to say, it becomes the appearance of winter.
There is a light snow all over the sky, and the coming year will be rich.
As the agricultural proverb goes, "there is light snow all over the sky, and the coming year will be rich." The ancients believed that light snow had just entered winter, and it was a good sign that it began to snow at the beginning of winter. Until next year, the rain would be even and there would be no drought or flood. Wang Liwei believes that this agricultural proverb first expresses a good wish. In addition, it also contains certain scientific truth. "Secondly, it snows when it snows lightly, which will directly freeze the pests and germs in the farmland. By next year, it will reduce the pests and diseases in the fields and ensure the healthy growth of crops. Finally, it snowed when there was a light snow, and the earth began to enter the freezing period. And this snow can be like a quilt, which can keep the crops warm, which can not only block the invasion of cold air, but also reduce the heat transfer from the soil. "
Take winter wheat as an example. Covering with snow can protect wheat seedlings from overwintering safely. Wang Liwei said that in general, the newly fallen snow has large pores and the best heat preservation effect. If the snow is kept above 3 cm, it will be very helpful for winter wheat. Moreover, the melting of snow in the coming year can replenish soil moisture, make the soil wetter, and also promote the decomposition of organic matter in the soil and improve fertility. Therefore, there are also sayings that "winter wheat is covered with three layers of quilts, and next year I sleep with steamed bread under my pillow" and "snow is auspicious for a bumper year". These agricultural proverbs are valuable experiences summed up by the ancient working people through long-term exploration. Although it is not applicable to all parts of the country, it still has high reference value for some agricultural production in the north.
Busy farming in light snow season
In ancient times, it was not cold enough to go out during the light snow season. So at this time, the ancients advocated "repairing" and "visiting friends". Even so, there are still some farming things to worry about.
Wang Liwei introduced that wheat should be hoed and crushed and suppressed in winter to ensure the safe overwintering of wheat seedlings and lay a good foundation for next spring. For winter rape, it is necessary to pay close attention to thinning seedlings, fixing seedlings, cultivating soil in intertillage and applying fertilizer reasonably to improve the cold resistance of rape. For livestock, it is necessary to catch autumn fat and prepare enough grass food, such as straw, vegetable leaves, sweet potato vines, etc. In winter grazing, it is necessary to go out late and return early, livestock and poultry houses should take measures to keep warm and keep out the cold, and fruit trees should be cut quickly. According to the characteristics of each crop, planning ahead of time is to have a good harvest in the coming year.
Rape transplanting began in some areas of Sichuan Basin in the light snow solar term, and winter wheat is also in the three-leaf stage. It is necessary to do a good job of fertilizer and water management for weak seedlings before winter, and strive to cultivate strong seedlings for overwintering. All orchards should make full use of favorable weather conditions to complete the management of overwintering orchards in time to ensure the safe overwintering of fruit trees in the later period. When planting vegetables in greenhouse, we should also pay attention to ventilation while keeping warm, so as to prevent wet-loving diseases such as downy mildew and gray mold caused by high humidity.
Poster production of Xiaoxue solar terms: Liu Yuxi