ABSTRACT:

This study assessed the suitability of floodplain soils along the River Chanchaga in Niger State, Nigeria, for sustainable rice production. Three physiographic units (upper, middle, and lower slopes) were identified within the upstream floodplain, with three profile pits dug and sampled at each location according to FAO guidelines. Standard laboratory procedures determined soil properties. Qualitative land suitability evaluation, comparing soil characteristics with rice requirements, indicated the soils were currently unsuitable (N) for rice cultivation, primarily due to limitations in chemical properties. Upstream soils exhibited sandy loam, sandy clay, and clay loam textures, with a dominance of sand (402-842 g kg⁻¹). Soil pH ranged from slightly acidic to neutral (5.5-6.8), while organic carbon was high across all sites. Nitrogen and phosphorus distribution varied with depth. Calcium was the dominant exchangeable base, while potassium was moderate (<0.30 cmol kg⁻¹). Cation exchange capacity (CEC) and percentage base saturation (BS) were moderate to high (63.4-88.5%). Quantitative land suitability evaluation using the Storie method also classified the upstream area as unsuitable (N), although the Rabia equation indicated moderately suitable (S2). This comprehensive analysis highlights the need for soil improvement strategies to enhance the suitability of these floodplain soils for rice production.