Soil scientists well know the role of biological factor as one of the five major natural factors driving soil formation and evolution, but they rarely ask about the role of soil in the origin and evolution of plants. I believe that the origin and evolution process of land plants is essentially an adaptation process to the soil environment. It means that the soil environment has a "mold effect" on the formation and evolution of the plants. The diversity of soil environments in profile thickness and layer configuration, physical, chemical and biological properties provides a basis of the formation of the plant diversity. Since plant roots grow in the soil, by absorbing nutrients from the soil to meet their growth demands, the role of soil environment on the formation of plant characteristics is mainly reflected in the genetic characteristics of plant root phenotype, nutritional physiology and resistant physiology to the stress of soil environments. Soil-plant diversity builds diverse habitats for different types of organisms and plays a key role in the formation and maintenance of biodiversity. Protecting the diversity of soil environment is crucial for biodiversity protection, and the key is to protect the heterogeneity of soil environment. In order to enhance crop yields, the cultivation processes of cropland soils are, in essence, the homogenization processes of soil properties, hence, it is not conducive to biodiversity protection. It is of great significance to trace the soil environment in which crops originate, understand the crop genetic characteristics formed by the originated soil environment for the crop allocation, breeding, and crop nutrient management, and so on. However, the research requires not only rich knowledge in soil science, but also rich knowledge in other disciplines, particularly in molecular genetics. Therefore, conducting research in the field will expand research fields of soil science, re-understand the importance of soil resources, and promote the cross-integration of soil science and other disciplines.