Land suitability evaluation for the production of common beans (Phaseolus vulgaris), groundnut (Arachis hypogaea) and soybean (Glycine max) on ferralsols of bandjoun (Western Cameroon)

Abstract

The Ferralsols of Bandjoun, in western Cameroon, are characterized by low chemical fertility, directly limiting the soils' capacity to support optimal legume growth. This study evaluates the suitability of these Ferralsols for supporting the production of common bean (Phaseolus vulgaris), groundnut (Arachis hypogaea), and soybean (Glycine max), while analyzing the major biophysical constraints limiting their productivity, given the socio-economic importance of these crops. After describing two characteristic soil profiles in the study area, the soil suitability assessment, carried out using a modified FAO parametric method, classifies these soils as marginally suitable (S3) for the cultivation of the three legumes. The suitability subclasses are S3(c,f) and S3(c,t,f) for the two soils studied. The identified biophysical constraints are primarily insufficient rainfall (300–364 mm) during the growing cycle, particularly in the second month (70 mm); soil fertility, especially low sum of bases and base saturation; and topography (5.6–16% slope). To improve crop productivity in the Bandjoun area, smallholder farmers need to choose planting dates appropriately based on a prior study of rainfall distribution, use ridging techniques perpendicular to the slope, and adopt organic and mineral fertilizer practices to improve the availability of essential nutrients.