Shifting cultivation, also known as slash and burn agriculture, is a farming method used by over 300,000 people worldwide. It involves clearing areas of forest for crops, which are grown for a few years until soil fertility declines, at which point a new area is cleared. Population densities are very low, around 1 person per square kilometer, due to the dispersed settlement pattern required with frequent field relocation. Crops grown include manioc, maize, bananas, and other fruits and vegetables. After several years of use, fields are abandoned to allow the forest and soil nutrients to recover through natural regeneration.