"Xue Rui heralds a bumper harvest year" is an agricultural proverb widely circulated in China. In the north, a thick layer of loose snow is like covering wheat with a quilt to keep out the cold. The cold nitrogen in snow is easily absorbed and utilized by crops. The low temperature of snow water can freeze the overwintering pests on the surface and bring benefits to agricultural production. So there is another agricultural proverb, "wheat covers three layers in winter and sleeps with steamed bread in the next year."
Snow has a wide range of functions, but it is of great benefit to mankind. First, it is beneficial to the growth and development of crops. Because of the poor thermal conductivity of snow, covering the soil surface with a layer of snow cover can reduce the diffusion of soil heat and block the invasion of cold air on the snow surface, so the crops protected by snow can survive the winter safely. Snow can also store water for crops. In addition, snow can enhance soil fertility. According to the determination, every 1 liter of snow water contains about 7.5 grams of nitride. Snow water permeates the soil, which is equivalent to applying nitrogen fertilizer once. Feeding livestock and poultry with snow water and irrigating crops can obtain obvious benefits.
Snow is both beneficial and harmful to people. In mid-spring in March and April, if it suddenly snows because of the cold wave. It will cause severe cold. Therefore, the agricultural proverb says, "La Xue is a treasure, but Chun Xue is not good."