Slash - and - burn is used by 200 -- 500 million people worldwide. In 2004 it was estimated that in Brazil alone, 500,000 small farmers each cleared an average of one hectare (2.47105 acres) of forest per year. The technique is not scalable or sustainable for large human populations. Methods such as Inga alley farming have been proposed as alternatives which would cause less environmental degradation.
what is the main disadvantage of the slash and burn method of growing crops
not scalable or sustainable for large human populations