Definition:

Soil is a mixture of Organic matter, minerals, gases, liquids and organisms that together support life.

Classification of soils: 

Soils are classified on the basis of their formation, colour, physical and chemical properties. Based on these, soil is classified into six major types.

They are:

Alluvial soil, Black soil, Red soil, Laterite soil, Mountain soil, Desert soil.

Alluvial soil:

• Found in the regions of river valleys, flood plains and coastal regions.
• Formed by the deposition of silt by the running water.
• Most productive of all soils.
• Suitable for the culitivation of sugarcane, jute, rice, wheat.

Black soils:

• Formed by weathering of igneous rocks.
• Clayey in nature.
• Retains moisture.
• Ideal for growing cotton.

Red Soils:

• Formed by weathering of metamorphic rocks and crystalline rocks.
• Found in semi – arid regions.
• Not a fertile.
• Is soil brown red in colour due to the presence of iron oxide
• Suitable for millet cultivation.

Laterite soils:

• Formed by the process of leaching. 
• Found in trophical regions, which experienced alternate wet and dry condition. 
• Infertile soil. 
• Suitable for plantation of tea and coffee.

Mountain soils: 

• Found in slopes of mountains. 
• Thin and acidic in nature. 
• Nature of soil differs based on the altitude.

Desert soils: 

• Found in hot desert region. 
• Porous and saline in nature. 
• Infertile in nature. 
• Agriculture not successful.