What are the stresses on the vernal equinox and solar terms?

People often plant trees during the vernal equinox and solar terms. If it is sunny, nothing will happen. In other places, it is forbidden to pick dung at the vernal equinox, wash clothes by the river and dry clothes, all of which are related to the vernal equinox looking forward to rain. At the vernal equinox, the temperature began to rise, the weather in the north became warmer, the atmosphere rose, the frozen soil completely melted, and the soil was breathable. It is a good season for sowing. Spring rain is needed after sowing, and sunny days without rain are strictly prohibited at the vernal equinox.

When the vernal equinox comes, the rainfall increases obviously, and the national average ground temperature is stable above 10 degrees, which is the spring temperature defined by climatology. However, after the spring equinox and solar terms, the climate is mild, the rain is abundant and the sun is shining. Winter crops in most parts of China enter the spring growth stage, which is also the sowing time of early rice. The vernal equinox has three stages: "wait for the mysterious bird to arrive, wait for the thunder to sound, and wait for the electricity to start." Sending pictures of spring cows is also one of the customs of the vernal equinox. In addition, the vernal equinox customs such as offering sacrifices to hundreds of birds and sticking birds' mouths also carry people's expectations for farming time.