Horticulture is plant cultivation by slash and burn, or shifting cultivation . Horticulturalists leave fields fallow as they become depleted of sufficient nutrients to maintain productivity. Horticulture is common today in tropical forests of the Amazon Basin. The Yanomamo are among horticulturalists who must move their villages periodically as fields lose their fertility, and plots must be prepared farther and farther from home. Their work week is closer to 25 hours per week, and horticultural societies are also egalitarian, with no permanent political authorities.
Agriculture is intensive food production, and especially plant cultivation.
More labor is required to increase productivity on a given parcel of land. Irrigation and terracing are techniques of increasing productivity by controlling water and soil erosion. However, they require time and labor expenses that imply settled, permanent villages and permanent political authority to manage land and water rights, and to coordinate work details to maintain the infrastructure. Pastoralism is animal herding on a part, or full-time basis. Full-time pastoralists, like the Basseri of Iran , are nomadic peoples moving up and down the mountain slopes with the seasons and ripening pasturage.