SUITABILITY EVALUATION OF SOILS OF RIVER CHANCHAGA DOWNSTREAM FLOODPLAIN FOR RICE PRODUCTION

This study assessed the suitability of floodplain soils along the River Chanchaga downstream in
Niger State, Nigeria, for sustainable rice production. Three physiographic units (upper, middle,
and lower slopes) were identified within the downstream 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 marginally and moderately
suitable for rice cultivation, primarily due to limitations in chemical properties. Downstream
soils exhibited sandy clay loam, Silty clay, Silty clay loam and clay loam textures, with a
dominance of sand (532-842 g kg⁻¹). Soil pH ranged from slightly acidic to neutral (5.8-6.8),
while organic carbon was low across all sites. Nitrogen and phosphorus distribution varied with
depth. Calcium was the dominant exchangeable base, while potassium was moderate (<0.32
cmol kg⁻¹). Cation exchange capacity (CEC) and percentage base saturation (BS) were low to
high (33 -77%). Quantitative land suitability evaluation using the Storie method also classified
the downstream area as unsuitable (N), but the Rabia equation indicated moderate suitability
(S2) after amending the fertility status. This comprehensive analysis highlights the need for soil
improvement strategies to enhance the suitability of these floodplain soils for rice production.