Farmers select a piece of land cultivate it for a few years after the land loses its fertility they burn it and start cultivation in another piece of land
a plot of land is cleared in shifting cultivation by felling trees and burning them. The ashes are then mixed with the soil and crops like maize, yam, potatoes and cassava are grown. Shifting cultivation is practiced in the Thickly forested areas of Amazon Basin, tropical Africa, parts of Southeast Asia and North East India. These are the areas of heavy rainfall and quick regeneration of vegetation. Shifting cultivation is also known as 'slash and Burn' agriculture.
Shifting cultivation is a practice in which the field id left uncultivated after harvesting a certain amount of crop . This is done to replenish the soil so that it can gain its nutrients back . and they graw some crops and then burn the whole field and grow the new seeds in the ash and mix it with the soil . The field could be left fallow for maybe 7 or 8. years
Others employ land clearing without any burning, and some cultivators are purely migratory and do not use any cyclical method on a given plot. Sometimes no slashing at all is needed where regrowth is purely of grasses, an outcome not uncommon when soils are near exhaustion and need to lie fallow. In shifting agriculture, after two or three years of producing vegetable and grain crops on cleared land. Trees and bushes are cleared by slashing, and the remaining vegetation is burnt.
no trees are burned
if u dont know then see on internet
its burnt