Auspicious snow heralds a good harvest(ruì xuě zhào fēng nián)

Auspicious snow heralds a good harvest

Ruixue is a Chinese idiom, the Pinyin is Ru à Xu à zh à of à ngni á n, which means timely winter snow indicates that the next year is a year of harvest. It's a good omen for the next year's harvest. As the saying goes: "snow is a good omen for a good harvest." the wheat harvest will be good next year

Basic introduction

It's cold in winter, and the snow is not easy to melt. The snow on the soil is relatively soft, which hides a lot of stagnant air, and the air does not transfer heat. This is like covering a quilt for crops. No matter how cold the weather is outside, the temperature below will not drop very low. It's not easy to attract insects when it's covered by winter snow. when the cold wave is over, the weather is getting warmer and the snow is melting slowly. In this way, not only the crops are protected from freezing injury, but also the water melted by the snow is left in the soil, which accumulates a lot of water for the crops, which is very beneficial to the spring sowing and the growth and development of the crops.

Heat preservation

Snow, like a wonderful carpet, covers the earth, so that the ground temperature will not fall too low due to the severe cold in winter. The heat preservation effect of snow is inseparable from its own characteristics. We all know that it's warm to wear cotton padded jacket in winter. Why is it warm to wear cotton padded jacket? This is because the porosity of cotton is very high. The pores of cotton are filled with a lot of air. The thermal conductivity of air is very poor. This layer of air prevents the heat of human body from diffusing outward. The snow covering the earth's chest is very similar to cotton. The porosity between snowflakes is very high. That is, the layer of air drilling into the snow pores protects the ground temperature from falling very low. Of course, the heat preservation function of snow is changing with its density at any time. This is very similar to the situation that the new cotton padded jacket is very warm, while the old cotton padded jacket is not very warm. The density of new snow is low, the air stored in it is more, and the heat preservation effect is particularly strong. Old snow, like an old cotton padded jacket, has high density and less air stored in it, so its heat preservation function is weak. why is the more air stored in the object, the stronger the insulation effect? This is because air is a bad conductor. We know that any object itself can pass through heat. This property of passing through heat is called the thermal conductivity of the object. Among the common substances in nature, the thermal conductivity of air is the worst. So the more air an object contains, the worse its thermal conductivity. Because the amount of air contained in snow varies greatly, the thermal conductivity of snow also varies greatly. Generally, the newly fallen snow has large pores and has the best heat preservation effect. In the later stage of snow melting in spring, the snow is soaked by water, and its thermal conductivity is closer to that of water, so the heat preservation effect of snow tends to disappear.

Add fertilizer

Snow contains a lot of nitrogen compounds. According to the observation, if 1 liter of rain water can contain 1.5 mg of nitrogen compounds, then 1 liter of snow can contain 7.5 mg of nitrogen compounds. During snowmelt, these nitrogen compounds are carried into the soil by snowmelt water and become the best fertilizer.

Freeze to death pests

The snow cover keeps the soil warm, which is good for the insects that drill underground for the winter. But when melting snow, we need to absorb a lot of heat from the soil. At this time, the soil will suddenly become very cold, the temperature will drop a lot, and the pests will freeze to death. So a few heavy snow in winter is a good omen for the next year's harvest. There are folk proverbs about snow and crops. For example, "auspicious snow heralds a good harvest", "three layers of wheat cover in winter, sleeping with steamed bread next year", "light snow in the sky, next year will be a good harvest", "snow covered land, double years", "more snow in good harvest" and so on. What's the scientific reason for this? Yes, because there is a heavy snow in winter, the field is like covered with a big quilt. The heat in the field is not easy to disperse, so as to protect the overwintering crops from freezing. In addition, when snow water melts and penetrates into the soil, most of the overwintering eggs will be frozen to death, which will reduce the number of pests in the next year, which is conducive to the growth of crops. Therefore, there is a folk saying that "auspicious snow heralds a good harvest". However, there is also a folk saying that "snow in winter is plentiful, snow in spring is troublesome". Why is snow so annoying in spring? This is because the temperature gradually rises in spring, winter crops encounter a spring snow, will freeze. In addition, too much spring snow will affect traffic, and too wet land will hinder underground work. So it's not bad at all to say that spring snow is a nuisance. "auspicious snow" is due to the antifreeze and warm keeping effect of snow cover layer on overwintering crops. Heavy snow can prevent the heat in the soil from radiating outwards and prevent the invasion of cold air from outside. "Auspicious snow heralds a good harvest" lies in the function of snow to increase soil moisture and fertilize the field. The snow on the ground will melt slowly when the ground warms up in the next spring. The water loss of the melted snow is small, and most of it seeps into the soil, just like an irrigation, which is of great benefit to alleviate the spring drought and do a good job of spring ploughing and sowing. The melted snow water can bring more nitrogen compounds to the soil. Ruixue has such a unique function is determined by its own nature. First, the newly fallen snow is loose and porous, which can store a lot of air and has the function of freezing and keeping warm. Secondly, the content of heavy water in melted snow water is 25% less than that in normal water. Heavy water is a kind of radioactive substance, which has a strong inhibitory effect on the life activities of various organisms. The less heavy water content in snow is obviously conducive to promoting the growth and development of organisms. Thirdly, the physical and chemical properties of snow water are different from that of ordinary water. Due to the freezing of snow water, the gas in it is eliminated, and the electrical conductivity and density have changed. studies have shown that the physiological properties of snow water are very close to those of water in biological cells, so it shows strong biological activity. The ability of plants to absorb snow water is two to six times greater than that of tap water. After entering the organism, snow water can stimulate the activity of enzymes and promote metabolism. Fourth, there are more nitrogen compounds in snow water, which is five times more than that in rain water and higher than that in ordinary water. It can be said that snow water is a kind of fertilizer water. Finally, heavy snow can kill most of the pests, and there will be less pests in the coming year. However, winter snow is harmful to the main crops in the south. For the vast southern region of China, heavy snow in winter is just a disaster; wheat and other crops with higher income from winter snow are planted less in the south. Therefore, as an agricultural proverb, the auspicious snow year usually refers to the northern region

Idiom explanation

Name: Ruixue zhaofengnian Pinyin: Ru ì Xu ě zh à of ē ngni á n. The timely winter snow indicates that the coming year will be a good harvest year. Heavy snow in winter is a sign of a good harvest in the coming year. Qu Bo's "bridge long Biao" 19: "as the saying goes:" auspicious snow is a good year ", next year's wheat harvest will be good." There will be a good year next year. usage: as object and attribute;

Folktales

It is said that three immortals in the sky are in charge of the snow in the world. Zhou qiongji is in charge of Furong City, and Dong Shuangcheng is in charge of the snow storage glass bottle. There are several pieces of snow in the glass bottle. When the clouds are thick, Gu Shezhen knocks out a piece of snow with golden tendons, and the snow begins to fall in the world. The creator gives the snowflakes to winter, which makes winter lively in the desolation and adds fun in the silence. Farmers like snow even more. Once they see snow flying all over the sky and thick piles of snow on the ground, they have a premonition of the harvest joy in the coming year. "Auspicious snow heralds a good harvest" is actually people's heartfelt admiration for snow and their good wishes.

Chinese PinYin : ruì xuě zhào fēng nián