Evaluation Of Management Properties Of Wetland Soils Of Akwa Ibom State, Nigeria For Sustainable Crop Production

Abstract

Management properties of soils of three wetland types in Akwa Ibom State were investigated. The wetland types are Inland Valley, Flood plain and Mangrove. The soils had silt/clay ratios above 0.15 and 0.25 indicating that they are of young soils. The pH of the wet soils was very slightly acidic (>6.4) while that of the air-dried samples was extremely acidic (>3.5). This suggests that the soils are potential acid sulphate soils. Organic matter content values were high with mean of 12.59, 60.01, and 3.20 percent for Inland valley, Flood plain and mangrove soils respectively. Effective cation exchange capacity (ECEC) was below the >20 cmol/kg reported by FAO (1976) as indicative of high suitability of soil for crop production. There was negative and significant correlation between ECEC and pH in Flood plain soils (r= -0.76) and positive but non-significant correlation between ECEC and organic matter in all the wetland types. The soil had low base saturation (<38) and high percent aluminium saturation of above 60. Electrical conductivity was above the critical value of 2dsm-1 for sensitive crops. Exchangeable sodium percentage was less than 15 percent in all the wetland types. The soils had narrow C: N ratio of less than 20:1. The three wetland types, Inland, Flood Plain and Mangrove had mean clay content of 6.8, 25.6 and 11.3 percent and mean Fe₂O₃/clay ratio of 0.06, 0.11 and 0.11 respectively.

Journal of Applied Chemistry and Agricultural Research Vol. 7 2000-2001: pp. 26-36