Soil health is defined as "the continuous ability of soil to maintain its function as a dynamic life system". At the same time, it is considered that only soil with biological activity and function can be defined as healthy soil. The soil of biological communities with diversity and activity must be rich in soil nutrients, and vice versa. Considering both soil health and soil quality in time scale, soil health can be used to describe the "potential" and "dynamic" state of soil in a short time, and soil quality can be used to describe the "internal" and "static" state of soil in a long time scale. Anderson pointed out that soil health should mainly focus on the biological composition of soil. Some low-quality soils can be considered as healthy, such as: one is the soil in the early stage of succession or the soil with unfavorable environment such as sandy land, desert and polar regions, with low biodiversity and biological production potential, but it is actually in the natural development stage; The other is the soil at the climax of ecosystem succession, such as tropical rain forest with high biodiversity and low fertility. On the contrary, the soil destroyed by ecology or polluted by environment, such as desertification soil or petroleum hydrocarbon contaminated soil, is not in a healthy state. It can be seen that in natural ecosystems, soil quality and soil health are not completely equal, and in disturbed ecosystems, especially in polluted environments, their connotations are not consistent. In this sense, they should be distinguished in the study. The word "health" refers to a state in which an organism or its parts can normally perform its important functions. Soil health should mainly consider the biological composition of soil and the functionality of soil ecosystem, especially the functions of maintaining energy flow, material circulation and information exchange in the system. Based on the above analysis, soil health can be summarized as "the continuous ability of soil to maintain its function as a dynamic life system".
The determination and evaluation of key indicators of soil health is of great significance to global land management and agricultural production. The physical, chemical and biological characteristics of soil are generally included in the price system of soil health. However, in recent years, the first two methods are not often adopted by people, but the biological characteristic method is gradually adopted by people.