Soil as a Resource
Soil is the naturally occurring, unconsolidated or loose covering on the Earth's surface.
Soil is composed of particles of broken rock that have been altered by chemical and environmental processes including weathering and erosion.
The formation of soil happens over a very long period of time. It can take 1000 years or more. Soil is formed from the weathering of rocks and minerals.
The surface rocks break down into smaller pieces through a process of weathering and is then mixed with moss and organic matter. Over time this creates a thin layer of soil.
The plants attract animals, and when the animals die, their bodies decay. Decaying matter makes the soil thick and rich.
This continues until the soil is fully formed. The soil then supports many different plants.
The important factors in the formation of soil
Parent rock or bed rock
Other forms of life
Classification of SoilsIndia is blessed with different types of soil due to the presence of varied landforms, climate, vegetation.
|Alluvial||Due to deposition made by the rivers.||Consists of different proportions of sand, silt and clay.
Classified into 2 types on the basis of their age.
Rich in potash, phosphoric acids and lime.
These soils are intensley cultivated as they are very fertile.
|Northern plains covering the states of Punjab, Haryana, Uttar Pradesh, Bihar, West Bengal and Assam.
Also found in the eastern coastal plains in the deltas of Mahanadi, Godavari, Krishna and Kaveri.
|Black||Weathering of lava sheets||Ideal for the growth of cotton
Water retention capacity is high as it clayey.
Becomes sticky during rainy season and develops cracks during summer(helps in aeration).
Rich in calcium carbonate, magnesium, potash and lime.
Poor in phosphoric acid.
|Deccan Trap coveing the states of Maharashtra, Gujarat, Madhya Pradesh|
|Red and yellow||Weathering of ceystalline igneous rocks in the low rainfall regions||Appears reddish in colour due to the presence of Iron oxides.
Appears in yellow colour when it occurs in hydrated form.
|Orissa, Chattisgarh and southern parts of middle Ganga plains.|
|Laterite||Leaching due to heavy rainfall||Name is derived from a latin word 'later' meaning brick.
Formed in the areas of high temperature and heavy rainfall . Hence the presence humus content is very low.
Useful for growing tea and coffee.
|Karnataka, Kerala, Tamil Nadu, Madhya Pradesh, Orissa and Assam.|
|Arid||Weathering in dry areas.||Sandy in texture and saline in nature.
Lacks humus and moisture.
|Thar Desert in Rajasthan.|
|Mountain or Forest||Weathering in hilly regions||Found in the hilly regions where forests are available.
Loamy in valley sides and coarse grained in the upper slopes.
|Jammu & Kashmir and Himachal Pradesh.