Soils of the Darror Valley (northeast Somalia)

Abstract

Summary The Darror Valley is located in the arid part of northeast Somalia. Its soils are highly influenced by their parent material, which consists mainly of evaporites, limestone, conglomerate and alluvial deposits. The most common soils in this area are calcic Solonchaks, gypsic Solonchaks, gypsic Calcisols, haplic Calcisols, eutric Leptosols and calcic Vertisols. All soils have a neutral to weakly alkaline pH-value and are very rich in carbonates, often rich in gypsum, often saline, and their moisture content at the end of the dry season is much lower than the moisture content of the permanent wilting point. Most of these soils have a colour of 7.5 YR, which becomes more red in the subsoil. Analytical data indicate that the topsoils are usually enriched in carbonate, whereas the subsoils are enriched in gypsum and/or salt. The soil salinization is mainly due to Tertiary evaporite formations.