There are numerous reasons why soils differ regionally. The most influential factors include the parent material (the rocks from which the soil has come), the climate and terrain of the region, as well as the type of plant life and vegetation present, and, of course, human influence...
**Alluvial Soil;
These are fertile soil deposited by rivers on and near their banks. These soils are majorly found in the northern plains of the country. The most fertile alluvial soil is found in the Ganga valley, where it is deposited by river Ganges. These soils cover almost 35-40% of the region of India...
**Black Soil
Black Soil are characterized by their deep black colour. Their composition has a large amount of clay. This helps the black soil retain water, making them ideal for crops that require water year round. This also gives them a unique self-ploughing ability.
These soil are rich in lime, iron and magnesia. They are mainly found in the Deccan Plateau in Maharashtra, Madhya Pradesh, Gujarat etc. They are also known as Black Cotton Soil..
**Red Soil and Yellow Soil;
These distinct soils are named after their hues. Red soil gets its colour from the iron found in its composition in a crystallized form. The soil takes on a yellow colour when it is hydrated. These soils are generally found in the Western Ghats, Odisha and Chattisgarh.
The clay form of red soil is nutrient rich and viable for forestation...
**Laterite Soil;
Such soils are found in regions of high temperature and very high rainfall. The rains will wash all the nutrients from the soil, leaving it infertile. The leaching process will leave behind iron-rich soil, absent of silicon. The humus composition is also affected by bacteria and fungi that thrive in high temperatures...
**Arid Soil
These are the sandy soils that appear in extremely dry and arid regions of Rajasthan and Gujarat. These soils are completely void of any organic matter. They also have a very high saline content, making them largely infertile. Only desert vegetation (cacti, bushes etc) can grow in this type of soil.
**Saline Soil
These are also known as Usara soils. As the name suggests they have a very high saline content in their composition. They also have large quantities of potassium and magnesium, making them infertile. These soils are found both in dry regions and in swamps.