Many farmers in less densely populated area, such as Amazonia, practice slash and burn agriculture, also known as shifting cultivation or swidden agriculture where an area is cleared and then burned for the vegetative remains to release nutrients back into the soil. Shifting cultivation is a system where a farmer uses a piece of land, only to abandon or alter the initial use a short time later. Advantages of shifting cultivation includes; enhance control of pest and disease, inorganic matter addition which provide nutrient to crop, an effective way of weed control