ABSTRACT
Terraces for agriculture are found in many mountainous areas of the world. Because their construction and use is highly labor intensive and usually precludes mechanization, terraces today are used primarily by traditional farmers. Terraces have been used extensively in Africa and Asia. Terraces reduce erosion, manage irrigation water, and provide a level surface on which to cultivate crops. Terracing by the use of vegetative strips is becoming of increasing importance. The retaining walls of terraces for agriculture are constructed of various materials, mainly stone, on sloping land in mountainous areas. Irrigation of the terraces was accomplished by artificial channels leading down from water sources such as glaciers in the high mountains. W. M. Denevan noted that depopulation and climatic changes were the most common causes suggested for terrace abandonment. Almost all of the Peruvian terraces were built in pre-Columbian times.
