Characterization and classification of some Alluvial soils of the Lower Niger River floodplains in Bayelsa State, Nigeria

Abstract

For increased agricultural production, the place of adequate knowledge of soil properties and reliable soil data in the management of floodplain soils cannot be down-played. This study therefore, was conducted with the objective of characterizing and classifying some alluvial soils of the lower Niger floodplain in Bayelsa State, Nigeria to provide current and reliable data. Nine representative soil pedons were opened on various landscape positions, including levee crest, middle slope, lower slope and/or recent alluvial soils in the channel of the present active river in the three locations, described in the field and horizon-wise samples collected for morphological and physico-chemical analysis. The soils were deep, variation in soil colours (moist) within and among pedons in the different landscape locations very obvious as very dark grayish brown, very dark brown, dark brown, dark yellowish brown, and brown colours, dominated the surface and subsurface layers. Silt loam was the predominant soil texture. Soils were strongly acid to neutral [pH (H2O), 4.94-7.00], very low to medium organic matter (0.13-4.02%) and total N (0.01-0.25%) contents, low to moderate available P (3-21 mgkg-1), low to very high (0.10-2.13 cmolkg-1) exchangeable K and low CEC (1.49-8.06 cmolkg-1). The soils were classified as Aquic Dystrudepts, Typic Epiaquepts, Eutric Udifluvents, Humic Dystrudepts, Fluvaquentic Epiaquepts and Aquic Udifluvents using the USDA Soil Taxonomy and Fluvic Cambisol, Haplic-Fluvic Fluvisol and Haplic Fluvisol according to the WRB legend. Wetness, flooding, and soil chemical and physical fertility challenges were major constraints to increased and sustainable crop production in these soils.