Soil characteristics variability and land suitability for rainfed okra (Abelmoschus esculentus) along a soil sequence in Godola, Northern Cameroon

Abstract

Crop yields are declining in Northern Cameroon due to overexploitation of soils. The present work aims to characterize these soils from a morphological, physicochemical, mineralogical and geochemical viewpoint, and to assess their suitability for rainfed okra, the most widely consumed vegetable in the area. Three pedological profiles located at the upslope (G1), mid-slope (G2) and footslopes (G3) positions of a toposequence were studied. The main results show that these soils are light grey to pale yellow, with a medium to high cation exchange capacity (14.76-35.75 cmol kg-1), a low to very high sum of exchangeable bases (4.58-19.20 cmol kg-1) and a low to high base saturation (31.02-70.17%). Mineralogical composition consists mainly of quartz, calcite, kaolinite and smectites. The chemical composition shows a predominance of silica (48.69 – 80.04%), alumina (10.53 – 14.27%) and iron oxide (0.61 – 20.38%). The three studied profiles were classified respectively as Dystric Ochric Leptosols (G1), Eutric Arenic Fluvisols (G2) and Eutric Clayic Planosols (G3). Pedoclimatic assessment of okra cultivation reveals that soils of the study area are moderately (S2) to very suitable (S1) due to limitations imposed by soil physical characteristics (depth, slope, texture/structure) and fertility (organic carbon, base saturation and pH). Soil management practices such as liming, use of organic and mineral fertilizers, spreading of crushed basaltic rocks and termite mounds should be practiced here.