Morphology, Physicochemical Characterisation and Erodibility of Soils of Boboyo (Far - North Cameroon)

The present work contributes to the study of soils in the Northern part of Cameroon, precisely in Boboyo region soils. This work aims to study morphology and physicochemical characteristics of those soils and to assess their vulnerability to erosion. Methodology: Ten wells were dug according to two directions: one direction W-E and one direction NNE-SSW. The principal analyses carried out in a laboratory are the physicochemical analyses: the granulometric analyse and the proportioning of organic carbon, total nitrogen, the exchangeable bases, the pH and residual moisture. The erodibility indices are calculate starting from the physicochemical data of the soils.

Six types of soils were identified in Boboyo: alluvial soils (entisols, fluvisols) widely spread in the region, covering the seasonally flooded plain, lithosols were found in the upper part of the landscape, colluvial soils (arenosols, regosols) were located in the Piedmont, the vertical alluvial soils were located in lower part of the slope in flooded plain, vertisols and ferruginous indurate soils were founded between colluvial (arenosols, regosols) and alluvial soils (entisols, fluvisols). The physico-chemical analyses reveal that: the colluvial soils (arenosols, regosols) are neutral to weakly acid (7 to 5,4), clayey-sandy to sandy; the vertisols are weakly acid (pH=6,3), sandy-clay (sand =77,9 and clay=19,6); The alluvial soils (entisols, fluvisols) are acid to neutral (pH= 5,2 to 7), sandy (80%); the vertic alluvial soils are neutral (pH=7), clayey-sandy (clay 34,2 and sand 65,3) and ferruginous indurate soils (luvisols) are acid (pH=5,2), sandy. All these soils are saturated (78 to 98), poor in organic matter (0,72 to 2,89%) and nitrogen and characterised by moderate proportions of exchangeable bases. The assessment of the erodibility based on erodibility indices enables to show that alluvial soils (entisols, fluvisols) are most vulnerable to erosion while the colluvial soils (arenosols, regosols) are less susceptible.