What do these solar terms have to do with agriculture?
Beginning of Winter
Beginning of winter generally starts from the first ten days of June 165438+1October, that is, the 7th or 8th day of June165438+/October every year. The explanation of "winter" in the 24 solar terms is: "Winter is the end and everything is harvested". Winter means the end, and it also means harvesting crops after harvest. There is a saying that radish and onion are "beginning of winter" in production, which means that these crops should be harvested and stored at this time. In autumn, all crops have been harvested and put into storage, and animals have been hidden and hibernated. Beginning of winter not only represents the coming of winter, but also completely. beginning of winter means that winter has begun, everything has been collected, and animals have taken shelter from the cold.
China has a vast territory, including the South China coast without winter all the year round and the Qinghai-Tibet Plateau without summer. Therefore, the winters in different places basically have their own characteristics and laws, and they don't all start from beginning of winter.
In early winter, the solar radiation in the northern hemisphere is decreasing, so the heat is gradually decreasing. Only the ground has a certain amount of heat storage in summer, and it is generally not too cold. Although it is mostly cold weather at this time, it is inevitable that there will be warm and comfortable "Xiaoyangchun" weather, which makes people feel very comfortable and has a positive effect on the growth of winter crops. But at this time, the cold air force in the north is strong, and it constantly invades the south, which often leads to strong winds, rain, snow and cold waves, which has a negative impact on crop growth. Statistics for many years show that 165438+ 10 is the most frequent month for cold waves. Serious cooling effect, especially the abnormal changes of cold and warm weather, on the one hand affects agricultural production, on the other hand, it also has a serious adverse impact on people's health and life. At this time, we should pay attention to the weather forecast and do a good job in the defense of crop chilling injury and freezing injury according to weather changes.
The first drop of fine snow-light snow
Peony after the light snow solar term
Light snow is usually in late October of 1 1, which is 1 1.22+23 every year. Twenty-four solar terms: "In mid-October, it was raining and the cold was thin, so it condensed into snow. The words of the villain are not prosperous. " At this time, the temperature continued to drop and it began to snow, but it was not very heavy. In the north of China, it's time for ponds and dams to freeze. When the cold wind blows, people feel that "the sky is crisp and the cold current is urgent" and "it is already hundreds of feet of ice on the cliff". At this time, the field is only for the collection and storage of Chinese cabbage. Farmland work basically stopped. Due to the continuous snowfall, there is a saying in the farmer's proverb that "there is a light snow all over the sky, and the next year will be fruitful".
In the light snow season, the weather is getting colder, and the first snow period in the middle and lower reaches of the Yellow River basically conforms to the light snow solar terms. Although it begins to snow, the amount of snow is generally not large, and it usually freezes at night and turns during the day, which has very limited impact on agriculture. However, if the cold air is strong and the warm and humid airflow is active, it may snow heavily.
Heavy snow and loosening
Heavy snow usually occurs in early February of 65438+,that is, on February 7th or 8th of 65438+every year. "Twenty-four solar terms" said: "At this time, the snow is abundant." This solar term indicates that the temperature will continue to drop and heavy snow will come at any time, which will cause snow on the ground. Big means heavy snowfall. The ancient heavy snow is divided into three stages: "When the cuckoo gull doesn't sing; Second, wait for the tiger to pay; Wait for you to stand out. " It means that the weather is cold at this time, and Hao Han birds are too cold to sing; At this time, the yin is strong, and the so-called prosperity declines, so the yang begins to sprout and the tiger begins to courtship; Bluegrass feels that sunshine is the budding spirit, and sprouts new buds.
Major Snow
At this time, the earth froze and the pond froze. There is often a "heavy snow" that does not close the land, but it is said to be from the 3rd to the 5th. Once the clouds are overcast, people feel that there will always be magnificent pictures of "snow overwhelms the winter clouds in Bai Yunfei, flowers bloom and fall for a while" and "there are no birds in the mountains, no footprints in thousands of paths, a boat with a leaf, a bamboo cloak, and an old man fishing for the cold river-snow". Once it snows, the scenery in the north is covered with silver everywhere. When you see the snow-covered pine and cypress, you will think of Marshal Chen Yi's poem "The snow presses the pine and cypress, and the pine and cypress are tall and straight", and the integrity of being a man suddenly surges in your chest.
"Heavy snow" means that the weather is colder, and the possibility of snowfall is greater than that of light snow, but it does not mean that the snowfall must be great. On the contrary, after this solar term, precipitation will further decrease, especially in Northeast China and North China. The average precipitation in 65438+February is generally only a few millimeters, and it is even less in the northwest.
As the saying goes, "Xue Rui is a good omen". Snow covers the ground in winter, which can keep the temperature around the ground, especially crops, from falling very low because of the cold current, thus providing a good wintering environment for crops in winter. On the other hand, when the snow melts, it can also increase the soil water content and provide conditions for the growth of crops in spring. In addition, the content of nitride in snow water is about 5 times that of ordinary rain water, which has a certain role in enriching the fields. As a result, there is a saying that "this year's wheat will be covered with three quilts, and next year's steamed bread will sleep."
During this period, except for areas without winter such as South China and South Yunnan, the vast land of the country has been covered with winter clothes. The average temperature in Northeast and Northwest China even reached below-10℃, while the temperature in the Yellow River Basin and North China remained basically below 0℃, and the growth of winter wheat basically stopped. However, the growth of wheat and rape is still slow in Jianghuai and its south area, so attention should be paid to fertilization to lay the foundation for their safe overwintering and next spring growth. At this time, the wheat in South China and Southwest China has entered the tillering stage, so it is necessary to apply tillering fertilizer in conjunction with intertillage, and pay attention to furrow cleaning and drainage of winter crops. Although the weather is cold, the stored vegetables and potatoes should be checked frequently to keep ventilation, avoid temperature rise and excessive humidity, and prevent pit rot. Generally, it is necessary to keep the temperature as low as possible without being damaged by freezing.
The days are short and the nights are long-the solstice in winter.
Winter solstice
The winter solstice is generally in late February of 65438+,that is, about 65438+February 23rd every year. "Twenty-four solar terms" said: "On November 15th, the gas storage finally came to an end." "Tongwei Filial Piety and God Help" said: "The fifteenth day after the heavy snow is the winter of solstice, in mid-November. Yin and Yang began, and the sky went south and grew up. " "Zunxian Manuscript" said: "The day is south, the day is short, and the shadow is long, so it is called the winter solstice. People who' want' are extremely excellent. "
In the northern hemisphere, the days are the shortest and the nights are the longest. This is because at this time, the Arctic Circle in the northern hemisphere (that is, 66.5 degrees north latitude) is in the extreme night period like the Antarctic "summer solstice". For the Arctic, the polar night can last 174 days. From the next day, the daytime time increased by 1 min for 20 seconds, and the nighttime time decreased accordingly. In life, people will feel that it gets dark early and dawn late, and it is difficult to know the night. "Winter" means "cold" and "to" means "to", which means it is colder when it is close. This solar term marks the beginning of cold weather. In the astronomical calendar, in order to show the beginning and degree of cold, in the printed calendar, "nine" is often used, that is, the so-called nine, two nine ... nine nine. "September" comes from "winter solstice", that is, the weather is colder in 8 1 day, and the third "September" is the coldest. Therefore, there is also a saying of "Sanjiu Cold".
I first boarded March 9th-slight cold.
Slight cold usually occurs in the first ten days of 10 at 65438+, that is, on the 5th or 6th of 10 at 65438+ every year. Like severe cold, mild summer heat, severe summer heat and intense summer heat, slight cold is also a solar term indicating temperature change. "Twenty-four solar terms": "December solar terms, the first cold is still small, so the cloud. It will be big in half a month. " "Cold" means cold. It shows that it has entered the cold season of the year, but it has not reached the coldest degree. Slight cold and severe cold periods in most parts of China are generally the coldest periods. After the "slight cold", you have to "get out of the ice" for three or nine days.
In this season, the southern region should pay attention to winter application of wheat, rape and other crops, and Hainan and most southern regions should mainly do a good job in cold and antifreeze, accumulating fertilizer and building water conservancy projects. Generally, frozen water should be poured before winter, sufficient winter fertilizer should be applied, and bacon should be cultivated. Then, when the cold season comes, artificial mulching can be adopted to resist the invasion of cold, which can make crops more secure in winter.
In winter, there will inevitably be a cold wave. At this time, pouring dilute manure and sprinkling plant ash can effectively reduce the damage of low temperature to rape. Some vegetables cultivated in the open field can be sparsely spread on the vegetable bed as plastic film in winter, which will not affect the light, but also significantly reduce the cold wind between vegetable plants and effectively prevent the loss of geothermal energy. If the low temperature is strong, you can temporarily thicken the covering for temporary covering, and then remove it in time after the low temperature. Vegetables in the greenhouse should be exposed to the sun as much as possible. Even if it encounters rain, snow and cold weather, it can't be covered with straw curtains and other mulches for many days, so as not to destroy the normal photosynthesis of plants and lead to nutrient deficiency. Alpine tea gardens, especially those vulnerable to the northwest cold wind, should be covered with straw, weeds or plastic film to prevent the damage of dead branches and sandstorms caused by exhaust. Clear the snow on the branches of fruit trees in time after snow to avoid the situation of broken branches.
Slight cold into the ice-great cold
The severe cold usually occurs in the late June of 65438+ 10, that is, before the 20th of 65438+ 10 every year. "Twenty-four solar terms" said: "Mid-December, before the solution (slight cold)." Historical Records General Examination quoted Sanliyi as saying: "Great cold is the middle, and the upper form is slight cold, so it is called great cold ... extremely cold, so it is called great cold." At this time, the temperature dropped to the lowest point and the weather was extremely cold. This is the coldest season of the year. The weather is really chilly at this time, dripping into ice. When it snows, there is ice and snow everywhere. This is the reason why "Sanjiu" is usually cold.
People who are used to working in busy farming season often transport soil mixed fertilizer to the fields at this time. This fertilizer is called "wax fertilizer" to keep wheat warm and safe for winter. In life, people will make various preparations for the upcoming Spring Festival and buy "new year's goods". Because the whole space of life is surrounded by cold, it makes people feel like they are in a natural "freezer", so food will not go bad if it is left casually for a long time.
At this time, the cold wave frequently invades the south, which is the coldest period in most parts of China in a year. Under the strong wind and low temperature, the snow on the ground remains unchanged, and the world presents a cold scene of ice and snow. Meteorological observation records show that slight cold is more serious than severe cold in most parts of China; However, in some years and a few coastal areas, the lowest temperature may still appear in the severe cold solar terms. In severe cold season, the average temperature in most parts of southern China is 6℃ ~ 8℃, which is nearly 65438 0℃ higher than that in mild cold. The proverb "slight cold and cold, cold into a ball" shows that the great cold solar term is also a cold period. Therefore, we should continue to do a good job in the cold prevention of crops, especially pay attention to protecting livestock from severe cold.