A loose and porous structural surface layer developed on the earth's land surface where green plants can grow.

Comprehensive definition: (Formation-Composition-Function) It is a complex biogeochemical substance that is formed by a combination of factors such as organisms, climate, parent material, terrain, time, etc. on the earth's surface and is used for plant growth. It has a unique loose and porous structure. Structure

A dynamic ecosystem that provides mechanical support, moisture, nutrients and air conditions for plant growth, etc.

Land: The land part of the earth's surface and above, all environmental elements within a certain range of space below, and some results of human social production and living activities acting on space - a natural-economic complex.

The natural economic complex on the earth composed of air, soil, topography, hydrology, biology, and the results of past and current human activities

Including: earth scope, a certain area, three-dimensional space entity, natural comprehensive economy, etc.

Land is a vertical three-dimensional space composed of natural elements such as climate, landforms, rocks, soil, vegetation, and hydrology. Soil is only one component of it.

Land has strong "socio-economic attributes", while soil has weaker socio-economic attributes

natural fertility

artificial fertility

available fertility

Potential fertility

The economic benefits that soil can produce under the combined effects of soil fertility, environmental conditions and human factors

Soil productivity is determined by the fertility properties of the soil itself (basic, internal factors) and the external conditions that exert its fertility effects (external factors). In this sense, fertility is only the basis of productivity, not all of productivity. If soils with basically the same fertility factors are in different environmental conditions, their productivity may be very different from each other.

The soil layers formed by pedogenesis are called soil layers, and the complete vertical soil layer sequence is called the soil layer profile.

Humus layer A

Eluate layer E

Deposition layer B

Parent material layer C

Rock R

soil organic matter

soil organic matter

soil water

soil air

Soil is the most basic means of production in agriculture

Soil is an important component of terrestrial ecosystems

Soil is the most precious natural resource

Soil resources are the basis for sustainable agriculture

Contribute to ensuring adequate food and a clean environment for mankind

Macro research and micro research

comprehensive cross-research

Fieldwork

New technology application