Pests and diseases potentially exact a toll on production in the northern Andes. These threats can be managed, however, by using disease-resistant varieties or more costly but still remunerative inputs. In contrast to the northern Andes, the rural residents of the southern Andes are significantly poorer than those in other regions of the same countries. In the southern Andes, drought is accentuated by the cyclical occurrence of El Ni o. Three-quarters of the Altiplano lies between 3,600 and 4,300 meters above sea level.
Most land is in unimproved pasture.
Potato accounts for the lion's share of value of production among native Andean and introduced crops cultivated on the Altiplano. Conditions for crop production are harsh. Drought, hail, and frost are frequent visitors. Floods can severely damage crops on the relatively fertile, flat perimeter of Lake Titicaca. The comparative advantage of the Altiplano is in the extensive grazing of livestock, mainly sheep, cattle, and alpacas.