| dc.description.abstract | A semi-detailed soil survey at 1:20,000 scale was carried out in an area of approximately 8000 ha on the northwestern slopes of Mt. Kenya. The soils have developed mainly from intermediate igneous rocks (trachytes) and occur in four main physiographic units: mountains, footslopes, footridges and valleys. The soils of the mountains and valleys are mainly cambisols and leptosols; those of the footslopes are shallow andosols and cambisols; and those of the footridges are andosols; alisols and luvisols. The soils show diverse physical and chemical characteristics. They range from well to poorly drained, shallow to deep, dark reddish brown (10YR 4/6) to brownish black (10YR 3/2), silty loam to clay. Topsoil organic carbon lies between 1.6 and 12.5 percent, base saturation is between 57 and 93 percent, and the cation exchange capacity (CEC) is between 15.5 and 23.5 cmol kg-1. Soil pH in both topsoils and subsoils varies from slightly acid to neutral (5.3 to 7.2). The moisture regime is udic in the upper part of the mountain and ustic in the lower part (i.e. mean annual rainfall of 700 to 900mm), while the temperature regime is isomeric on the upper slopes and isothermic on the lower slopes (i.e. mean annual temperature of 8 to 150C and 15 to 220C, respectively). The soils are moderately fertile, with a reasonable moisture storage capacity | en |
