Soil Characteristics, Taxonomy and land suitability of a lateritic Mantle for rain-fed maize (Zea mays) Agriculture in the Cameroon Western Highlands

Numerous farmers experience a knowledge gap between the cultivation capabilities of land units (LU) responsible for spatial yield variability. This research aims to characterize and evaluate a lateritic toposequence for rain-fed maize in Western Cameroon. Five soil profiles dug along an N-S transect enabled assessing land suitability for maize using the FAO method. The main results revealed that LU N° 1 (Summit) and 4 (Footslope) are currently marginal (S3) for maize cultivation, caused by climatic and soil physical constraints. LU N° 2 (basin with outflow), 3 (Backslope), and 5 (endorheic basin) are unsuitable (N2 and N), due to poor root zone aeration and unsuitable topography. Improved management strategies could allow for the reclassification of land use (LU) categories as follows: Unit 1, currently classified as Rhodic Eutric Nitisol (Ferric), could be deemed moderately suitable. Units 2, 3, and 5, which are Gleyic Stagnosol, Pisoplinthic Plinthosol, and Stagnic Gleysol, respectively, could be classified as marginally suitable. Finally, Unit 4, identified as Eutric Nitisol, could be reclassified as suitable. For potential yields, 47% is marginal (5.13 t/ha), 34% is suitable (0.97-2.27 t/ha) and 18% is moderate (0-1.95 t/ha). Comparing actual and potential yields, under low and medium input farming, yields with low input increase from 0.9 t/ha (actual suitability) to 4 t/ha (potential suitability), while medium levels increase from 2.27 t/ha (actual suitability) to 5.8 t/ha (potential suitability). This increase highlights the importance of using modest inputs to boost soil productivity for maize. Key words: Lateritic toposequence, rain-fed maize, land suitability classification, actual yield, potential yields, Cameroon Western Highlands.