ABSTRACT

A field study was undertaken to characterize, classify and evaluate the suitability of some wetland soils of Akwa Ibom State for wetland rice, cassava and maize production. The study area covered Ekpene Ukpa, Ikot Ebo, Oto Akan and Etinan in Etinan Local Government Area (LGA); Esin Ufot, Esuk Oron in Oron LGA; Ibaka, Akai Ati, Ebughu, NungAtai Eta in Mbo LGA; Ekeya, EsukInwang, Okobedi, EbighiAnwa in Okobo LGA; Ikot Mbonde in Uyo LGA  A free method of soil survey was adopted. Soil profile description followed the FAO Guidelines on soil profile description. Soil samples collected were analyzed in the laboratory using standard procedures. The soils were classified based on USDA Soil Taxnomy and World Reference Base. Qualitative and quantative methods of land evaluation were used. Results showed that three soil mapping units: Floop plain (FP), Inland depression (ID) and Coastal swamp (CS) were delineated. Results showed that the soils were generally poorly drained to moderately and well drained with reddish brown(5YR 3/3) to dark grey (7.5YR 6/2) and dark brown (7.5YR 3/2), brown (10YR 6/4) to yellowish brown (7.5YR 5/8). The Flood plain has moderate to strong coarse to sub-angular blocky structure,with moderate sticky to plastic constistency and mostly loamy. The soils  have mean pH of 5.80, 0.21. cmol/kg K and 9.90 mg/kg P and a base saturation of  76 %..Soils of Inland depression and Coastal swamp are generally sandy, with weak structure and non-sticky to non plastic consistency. They have mean pH of 6.40 and 6.00 with mean exchangeable K of 0.12 cmol/kg respectively. The mean available P were 21.2mg/kg for (ID) and 3.60 mg/kg for CS with organic matter contents of 1.60 to 2.8o % for ID and 0.88 to 4.26 % fot CS. The base saturation of in ID and CS were 27.7 and 12.8 %, respectively. The soils were classified as Arenic Paleaquults, Arenic Endoaquepts in the USDA Soil Taxonomy and correlated with Gleyic Acrisols, Gleyic Cambisols and Gleyic Fluvisols in the WRB system. Soils of the Flood plain are currently not suitable (N1) for cassava, but marginally suitable (S3) for maize and wetland rice. Soils of the Inland depression are not suitable (N1) for cassava but marginally suitable (S3) for wetland rice and maize. Soils of the Coastal swamp are marginally suitable (S3) for wetland rise, cassava and maize, respectively. It is recommended that the soils are not recommended for commercial prduction of wetland rice, cassava and maize because of the inherent limitations. However, with adeguate drainage, optimal use of mineral fertilizers and liming the soils can be used for commercial production of the evaluated crops.