Nepal; agriculture and subsistence in the Khumbu, 1986. Sherpa with young yak. The economic emphasis of the Khumbu is on animal husbandry, and the breeding and tending of yaks and cattle was an important occupation when this photograph was taken. Yaks command a good price. On walled, flat terraces, Sherpas cultivate their staple diet of potatoes, barley, buckwheat, and in lower areas, rice. In this picture, taken at altitude 2900 metres, the land sustains the commercial cultivation of medicinal herbs although increases in production are limited by environmental degradation, largely through soil erosion.