Suitability Evaluation of Selected Wetland Soils in Nigeria for Rainfed Rice Cultivation

Thirty-eight wetland soils in four agro-ecological zones were evaluated for their suitability for rice (Oryza sativa L.) cultivation. The results indicated that climatic characteristics are near optimum. Currently, by non-parametric method, most (≥ 97%) of the pedons were found to be marginally suitable (S3). With the parametric method about 3% were highly suitable (S1), 74% marginally suitable (S3) and 23% not suitable (NS). Potentially by non-parametric method, 18% were of high (S1) and moderate (S2) suitabilities respectively, 58% were marginally suitable (S3) and 6% not suitable (NS). With parametric method, 24% were highly suitable (S1), 45 and 31% were of moderate (S2) and marginal (S3) suitabilities. The major limitations to rice cultivation on these soils are low CEC, organic carbon, exchangeable cations and available P, which may predispose rice plants to excessive Fe2+ uptake visually expressed as «bronzing » or «yellowing» symptoms. In this and similar environments in the region, good soil management is required before substantial improvement in rice production can be achieved