what is shifting cultivation?why europeans decide t ban it?

Shifting cultivation is the type of cultivation in which the farmers cut trees and clear the land for cultivation.They also burn the uprooted trees and mix their ashes in the soil so as to fertile the soil. After cultivation and harvesting they move on to other land and repeat the same process. The European foresters banned it because in this process, there are also chances of hazards like forest fires, loss of fertility and for stability in the state they wanted to control these nomadic tribes.