Living fencerows of the Rio San Miguel, Sonora, Mexico: Traditional technology for floodplain management

In southwestern North America, agriculture is limited by both arable land and available water supplies. In the upper Rio San Miguel, as well as in other narrow river valleys of eastern Sonora, Mexico, floodplain farming is dependent upon living fencerows for its environmental stability. Propagated fencerows of willow and cottonwood maintain, extend, and enhance floodplain fields. These ecological filters also protect fields from cattle, harbor agents of biological control of pests, and provide renewable supplies of wood. Traditional Sonoran farmers do not perceive cottonwoods and willows as phreatophytic pests, as their Anglo-American neighbors do. The stability of the upper San Miguelagroecosystem con-trasts with severely eroded conditions within the region's other arid watersheds.