It is deposited mainly by the three important Himalayan river systems. So, statement 1 is NOT correct. It can be found in Rajasthan and Gujarat, and eastern coastal plains as well. So, statement 2 is NOT correct. Soils in the drier areas are more alkaline and can be productive after proper treatment and irrigation. So, statement 4 is NOT correct as alkalinity is not always the case. For e.g. Brahmaputra alluvium is acidic in nature. Apart from the size of their grains or components, 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 a higher concentration of Kanker nodules than the Khadar. It has more fine particles and is more fertile than the Bangar. Alluvial soils as a whole are very fertile. So, statement 3 is correct.