Pedological Characterization and Soil Classification of Selected Soil Units of Morogoro District, Tanzania

Abstract

The study aimed at provision of research information by pedological characterization of soil units of Morogoro District, Tanzania. Three soil units were selected coupled with field reconnaissance survey. Soil pedons were characterized at Kiziwa (KZW-P1), Mkambarani (MKA-P1) and Fulwe (FUL-P1). Pedons were observed to be formed from in-situ weathering of granitic rocks under ustic moisture and iso-hyperthermic temperature regimes. Thirteen soil samples were described and analyzed for physica-chemical and mineralogical properties. KZW-P1 and FUL-P1 had red dark brown sandy clay and gravely clay (MKA-P1) top soils overlaying mainly clayey subsoil. Both pedons indicate clay eluviation-illuviation as a dominant pedogenic process with slightly acidic condition and P<7 except FUL-P1 with 23.8 mg/kg P in top soils. Organic carbon is low in both pedons while total N is low to very low. CEC values for both pedons are 33.8, 26.4 and 27 cmol(+)/kg respectively. CIA values indicates intermediate to strong level of weathering. In USDA Soil Taxonomy and the FAO-UNESCO soil classification system, Soils were classified as: Kiziwa Ultisols (Alisols), and Inceptisols (Cambisols) for Fulwe and Mkambarani, reflecting their differences in potentials and constraints and hence use and management. The results reflects variations in soil characteristics both vertically and laterally so as to account for spatial linkages within the landscape.