Alluvial soil is the most widespread and important soil of India.
Its characteristics are:
1. Alluvial soils are very fertile. Mostly these soils contain adequate proportion of potash, phosphoric acid and lime which are ideal for the growth of sugarcane, paddy, wheat and other cereals and pulse crops.
2. Soils in the drier areas are more alkaline and can be productive after proper treatment and irrigation.
3. The alluvial soil consists of various proportions of sand, silt and clay.
4. Alluvial soil particles appear some what bigger in size in the inlands towards the river valleys. In the upper reaches of the river valley, the soils are coarse. Such soils are more common in piedmont plains such as Duars, Chos and Terai.
5. Alluvial soils are also described on the basis of their age. According to their age, alluvial soils can be classified as Old Alluvial (Bangar) and New Alluvial (Khadar). The Bangar soil has higher concentration of Kanker nodules than the Khadar. It has more fine particles and is more fertile than the Bangar.
6. Alluvial soils are transported soils. Most of these soils are derived from the sediments deposited by the rivers. In the entire northern plains the soils are deposited by the three important river systems- the Indus, the Ganga and the Brahmaputra.
