Abstract

Soils of the western slopes of Kupe Mountain in Cameroon were characterized to understand their proper land use and sustainable management. Evaluation of land suitability for maize (Zea mays), beans (Phaseolus vulgaris) and Irish potatoes (Solanum tuberosum) were assessed, considering the socio-economic importance of these crops in Cameroon. Three sites, representative of the study area were identified following a toposequence; Nyassosso (900 m), Mbule (700 m) and Tombel (500 m) with soils, respectively, classified as: Hyperdystri – humic Leptosol (loami – andic), Skeleti – Umbric Andosol (colluvi – loamic) and Dystri – skeletic Andosol (Colluvi – loamic). Soil properties indicated that colour varies from black and brownish black at the surface to reddish brown in subsurface horizons with some horizons showing varied colours. The soils were friable and granular in structure, had low bulk density ranging from 0.38 to 1.08 g/cm³, and had a loamy texture. Chemically, pH_(H2O) ranged from strongly acidic to slightly acidic (4.8 - 6.2), organic carbon ranged from low to very high (0.88 - 7.26%), electrical conductivity was very low (0.02 - 0.29 dS/m), cation exchange capacity ranged from medium to high (20.5 to 38.08 cmol(+)kg^-1), total nitrogen from very low to very high (0.09 - 1.7%), available phosphorous from very low to low (7.13 - 19.76 ppm), Ca²⁺ from very low to high (2.08 - 10.64 cmol(+)kg^-1), Mg²⁺  from very low to medium (0.08 to 2.56 cmol(+)kg^-1), K⁺ from very low to medium (0.01 - 0.31 cmol(+)kg^-1) and Na⁺ was very low (0.01 - 0.05 cmol(+)kg^-1). Amorphous iron and aluminum ranged between 0.06 - 1.35 and 0.16 - 1.01%, respectively. Land suitability evaluation indicated that soils of Nyassosso were marginally suitable for rain-fed cultivation of Irish potatoes, beans and maize. Soils of Mbule were marginally suitable for rain-fed cultivation of Irish potatoes and maize but not suitable for beans, while soils of Tombel were marginally suitable for rain-fed cultivation of Irish potatoes and temporarily non suitable for rain-fed cultivation of maize and beans.

Key words: Mount Kupe, soil properties, suitability classes, climatic index, land index.