Soil Science has six well defined and developed disciplines. Scope of soil Science is reflected through these disciplines.
Soil Science : The science dealing with soil as a natural resource on the surface of the earth, including Pedology (soil genesis, classification and mapping) and the physical, chemical and biological and fertility properties of soil and these properties in relation to their management for crop production.
Soil fertility: Nutrient supplying properties of soil
Soil chemistry: Chemical constituents, chemical properties and the chemical reactions
Soil physics: Involves the study of physical properties
Soil microbiology: deals with micro organisms, its population, classification, its role in transformations
Soil conservation: Dealing with protection of soil against physical loss by erosion or against chemical deterioration i.e. excessive loss of nutrients either natural or artificial means.
Pedology: Dealing with the genesis, survey and classification
Soil can be compared to various systems of human body
Digestive – matters decomposition
Respiratory – air circulation & exchange of gases
Circulatory – water movement with in the soil system
Excretory – leaching out of excess salts
Brain – soil clay
Colour – soil colour
Height – soil depth
Components of Soil (Volume basis)
Mineral matter – 45%
Organic matter – 5%
Soil water – 25%
Soil air – 25%