Slash-and-burn agriculture involves cutting and burning forests to clear land for cultivation. It is used by 200-500 million people worldwide and involves little technology. Farmers cut vegetation, allow it to dry, then burn the land to remove pests and add nutrients before planting crops. While beneficial to small farmers by providing fertile land and multiple crops, slash-and-burn causes deforestation, erosion, nutrient loss and biodiversity loss if not given time to recover between burnings. Alternatives like crop rotation and agroforestry are encouraged to prevent environmental damage from this traditional practice.