formation of alluvial soil in india

Alluvial soils are formed mainly due to silt deposited by Indo-Gangetic-Brahmaputra rivers. In coastal regions some alluvial deposits are formed due to wave action. Rocks of the Himalayas form the parent material. Thus the parent material of these soils is of transported origin. Alluvial soils are transported soils. They are formed by deposition of materials or sediments (alluvium) brought in down by rivers that consist of silt, sand, clay, etc. ... Alluvial soil which is found in the deltas of river is called deltaic alluvium (coastal alluvium. The alluvial soil found in India, particularly in the Indo–Gangetic plain, is of two types: khaddar (pale brown, sandy clays to loamy, less calcareous and carbonaceous soil, and found in the low areas of valley that are regularly flooded) and older bhangar soils (dark colored, mostly clayey, and containing lime nodules.

Most alluvial soils are derived from the sediment being deposited by the river Ganga in the Indo–Gangetic plain, ranging from Punjab in the west to West Bengal and Assam in the east, as well as in the coastal areas of northern parts of Gujarat, Narmada, and Tapi valleys, which are formed by sea waves. 

Alluvial soils are by far the largest and the most important soil group of India. The widest occurrence of the alluvial soils is in the Indo-Gangetic Plain starting from Punjab, Haryana, Uttar Pradesh, Bihar, West Bengal and Assam in the east, northern parts of Gujrat also have some covers alluvial soils.

Alluvium consists of silt, sand, clay, and gravel and often contains a good deal of organic matter. It therefore yields very fertile soils such as those of the deltas of the Mississippi, the Nile, the Ganges and Brahmaputra, and the Huang rivers.

Alluvial soil can be classified into two groups on the basis of its age - the khaddar and the bhangar. The former is light in colour and is made up of newer deposits. The latter is the older alluvium and is composed of lime nodules or kanker and its composition is clayey. 

Alluvium soil is formed by the sediments brought down by rivers. The soil is fertile as it consists of very fine particles and is rich in potash, phosphoric acid and lime. Besides, the alluvial soil is a mixture of sand, clay and silt called loam. ... (Water molecules can hold fine particles of clay more tightly).

The colour of the alluvial soil is usually brown in colour as it is suitable for the purpose of agriculture. It is mainly found in the northern plains and in the costal plain it is reddish-brown in colour due to presence of iron oxide..

Alluvial soils are soils deposited by surface water. You'll find them along rivers, in floodplains and deltas (like the Mississippi Delta), stream terraces, and areas called alluvial fans. This last category results from larger floods, causing the soil to spread out in the shape of a triangle fan.