Soils of the Cuyo Region

Abstract

Cuyo is a heterogeneous environmental region with two major domains, the Western mountain ranges and the Eastern lowlands. The variety of environmental conditions is clearly reflected by the soils. Entisols are regionally dominant resulting from the balance of prevalent arid conditions together with coarse texture parent materials, and the relative young age (late Holocene) of the parent material. Humification and melanization are the dominant pedogenetic processes. Aridisols, the second most dominant soil order, reflect a long-lasting and complex evolution with evidences of calcification, gypsification and clay illuviation. Paleoenvironmental conditions (fossil criopedoturbation) are documented in the mountain domain, indicative of past glacial conditions as well as a wider extension of periglacial conditions (present and fossil Gelisols). Mollisols and Histosols are also present with a limited areal extension at some piedmont settings. The irrigated agricultural oasis of Cuyo, deeply transformed by human activities, has generated new conditions for soil development both in their physico-chemical properties (OM, P, N, texture and alkalinity) and the parent material. Negative colateral effects as salinization, piping, rill and gully erosion are now active. Consequently, soil management, particularly in the fragile ecotonal ambiance of Cuyo, is a major priority in land environmental programmes as elsewhere.