"瑞雪兆丰年" is a widely circulated agricultural proverb, meaning that several heavy snowfalls in winter serve as an omen of a bountiful harvest in the coming year. What is the scientific basis for this saying? According to experts from the provincial meteorological station, this is mainly due to the fact that heavy snowfall in winter can bring at least three benefits to farmland.
Firstly, heavy snow can keep the soil warm and retain water for the fields. Since winter weather is cold, fallen snow often does not melt easily. The snow covering the soil is relatively soft, with many trapped pockets of air that do not conduct heat. This acts like a cotton blanket for crops; no matter how cold it gets outside, the temperature below will not drop too low. After the harsh winter has passed and the weather gradually warms up, the snow melts slowly. Not only does this protect crops from frost damage, but the water left in the soil after the snow melts is very beneficial for spring plowing, sowing, and crop growth.
Secondly, heavy snow can enrich the soil with nutrients. Snow contains a lot of nitrates. Observations show that if 1 liter of rainwater contains 1.5 milligrams of nitrates, then 1 liter of snow can contain up to 7.5 milligrams of nitrates. When the snow melts, these nitrates are carried into the soil by the melting water, becoming the best fertilizer for crops.
Additionally, heavy snow can freeze pests. Although snow covering the soil provides insulation, which temporarily benefits pests that burrow underground for the winter, when the snow melts, it absorbs a lot of heat from the soil, causing the soil to suddenly become very cold and the temperature to drop significantly. This freezes the pests.
Therefore, having several heavy snowfalls in winter is extremely advantageous for a bountiful harvest in the following year.