Shifting cultivation is a class of primitive subsistence agriculture. In this, a plot of land is cleared by the farmer. This is done by felling the trees and burning them. The ashes are then mixed with soil and crops are grown. After some time, the land is abandoned and the farmer moves to a different place. This type of farming is common in the thickly forested areas of the Amazon basin, tropical Africa, parts of south-east Asia, and north-east India. It is also called “slash and burn” agriculture, because of the process of felling and burning the trees is involved.