Soil is a necessary condition for plant growth, and its nutrients, minerals and moisture are all necessary conditions for plant growth. The soil breeds plants and microorganisms. Plants provide nutrients and energy needed by humans and animals, and microorganisms can decompose and digest human excreta, so that the ecological environment can be recycled. It is only what the soil does indirectly for human beings, which directly provides a suitable living environment for human beings. It can walk on the earth, mountains, houses and caves, sheltering human beings from the wind and rain. It can be said that soil is not only the mother of human beings, but also the place where human beings belong. It was born, raised and left by the earth.