Soil is the thin layer of material covering the earth’s surface which is formed from the weathering rocks. It is mainly formed of mineral particles, organic materials, air, water and living organisms, all of which interact slowly and constantly.

Types of Soil: 

Indian soils have been classified into the following types on the basis of their structure and composition:

1. Alluvial soil 

2. Black or Lava soil 

3. Red soil 

4. Late – rite soil 

5. Mountain soil

1. Alluvial soil: This type of soil is found in the Great Northern plains of India. It is fine grained fertile soil, deposited by water flowing over flood plains, on river beds, and in India, it is spread, in an area of 8 lakh sq. km. Alluvial deposit, alluvial sediment, alluvium, alluvium – clayey or silt or gravel are its other names and it is carried by rushing streams and deposited where the stream slows down.

2. Black or Lava soil: This type of soil is found in lava region of South India and it stretches in an area of 5 lakh sq. km in India. It is formed by the weathering and cooling down of lava after a volcanic eruption. It is rich in humus, iron, and magnesia, lime and alumina. Since cotton has been the most common traditional crop grown in areas where black soils are found, so it is also called black cotton soil. It is also known as Regor soil. It requires very little irrigation.

3. Red Soil: It is porous soil. It does not have the capacity to maintain moisture. It needs irrigation after a few days. It is not fertile. It is brownish or reddish in colour. It contains ferrous particles. There are pebbles and stones also found in it. It lacks in calcium.

4. Late – rite Soil: Its colour is just like a clay brick. There is a primacy of pebbles in it. These types of soils are formed by the fragmentation of old rocks. There is an over – abundance of iron and aluminium, but lack of calcium, phosphorus, nitrogen, sulpher and humus is found. On drying up, it becomes as hard as a stone. This soil is suitable for tea farming.

5. Sandy soil: Sandy soil is a naturally – occurring granular soil, composed of finally – divided rock and mineral particles. It has abundance of alkaline substances. There is lack of nitrogen and humus in it. Due to its dryness and porous nature, it is always transported. It proves to be fertile in the areas where irrigation facilities are available.

6. Mountain Soil: It is immature soil which is a mixture of tiny pebbles and stones. Its upper layer is thin as well as acidic. It is formed by smaller and larger particles. In the areas where this type of soil is found, terrace farming is done, under which cultivation of potato and tea is practiced and in the lesser fertile areas, pastures are seen.