Introduction

A remarkable assemblage of agricultural techniques and an equally remarkable set of diverse soils have supported the changing societies of the Andean region. A concern with adaptive process places emphasis on the identification of selective pressures, variability of cultural practices, and the cultural, social, and economic criteria of selection or choice between alternatives. A processual approach to cultural ecology need not preclude interest in potentially stable adapted states. Cultures seldom have arrived at completely stable states. There have been many attempts to define and name the significant environmental zones of the Andes and relate them to crops and cultural adaptations. Special attention has been paid to John Murra's two systems of agriculture: potato farming in high elevations and maize farming in lower temperate elevations. Taxonomies of Andean land use have increasingly taken into account the notably conspicuous artificial agricultural landforms. These may include terraces, raised fields, canals, and other features.