Abstract:
A study was carried out in Mikese Ward, Morogoro District, with the objective to make an inventory·of
the soils of the area, to determine their physico-chemical and mineralogical properties and to classify
them. Eight soil profiles were identified and form three major groups of soils ·namely, very deep, well
drained, dark reddish brown to dark brown, sandy clay loams and sandy clays on the steep convex
slopes; very deep, well drained, dark brown to dark red, sandy clay loams and; sandy clays on the linear
slopes; and very deep, well and imperfectly drained sa1'1dy loams to sandy clay loams a~q sandy clays in
the valley bottoms. The soils of the convex and linear slC?pes classified as Isohyperthermic, deep, mixed,
Kanhaplic Haplustalfs and Isohyperthermic, deep, mixed Oxic Ustropepts representin~ a relatively advanced
pedogenic development as indicated by high contents of Fe, Al and,Ti and relatively low SiiAI ratios.
The soils of the valley bottoms classified as Isohyperthennic, deep, mixed, 'Typic Argiustolls,
Isohyperthermic, deep, mixed, Typic Tropaquepts and Isohyperthermic, deep; mixed, Fluventic
Ustropepts. These soils are of low to intermediate pedogenic development as indicated by the relatively
lower Fe, Al and Ti contents and both high Stand SilAI ratios. X-ray diffraction analysis revealed that
the studied soils have a mixed clay mineralogy including kaolinite and mica. Small amounts of smeciite
were identified in one profile with alkaline subsoil reaction. Bulk densities of surface horizons are rela~
tively lower than those of subsoils rangingfrom 1.1 to I. 6 Mglm3 in topsoils andfrom i.4 to i.-9Mglm1
in subsoils. Total porosity rangedfrom 40 to 58% in surface soiis and frbm'28 to,32 % in ~ubsoils. Available
water holding capacities of the soils are between 155 and 248 mmlm of soil. The soils IWve overall
poor supply of Nand P. The basic catio,!s Ca++, Mg+ + and, K+' are medium to high throughout the profiles.
The CEC of the soils is very low with values rangingfroin 6 to 13 cmol(+ J/kg soil). These results
imply that continuous utilization of the soils for c;rop production withoutproper management will result
into a drastic loss of soil fertility.
