Characterization, classification and evaluation of swampland soils

Thesis Abstract

An investigative Research study was carried out in Ndokwa West Local Government Area, Delta State, Nigeria. The aim was to characterize, classify and evaluate the potentials of swampland soils in the area. A reconnaissance survey was conducted and three distinct physiographic locations namely Abbi, Ndemmili and Onicha – Ukwuani were identified. In each location, four modal profile pits were dug, delineated, described and characterized for morphological properties. Soil samples were also collected from each of the pedogenetic horizons of the profiles in each identified location for the analysis of the physic-chemical properties of the soil. The soils were classified based on the USDA soil Taxonomy criteria. Data collected were computed using SAS (2010) and differences in mean separated using Duncan Multiple Range Test. Results of the study showed that the morphological features of the soils depicted a low chroma of less than 2, a hue value greater than 4 with significant mottling in all the pedons. Chemical properties evaluated indicated the soils were strongly acid with a pH range of less then 5; organic carbon content were moderate to high with a range value of 0.22 – 0.29%, total nitrogen across the pedons were low with a range value of 0.01 – 0.7gkg-1; Available phosphorus were low 0.6 – 9.0 mgkg-1, exchangeable bases of Ca, Mg, K and Na were low to moderate and ranged from 0.23 – 0.5.05 cmolkg-1. The effective cation exchange capacity were also low with a range values of 1.83 – 6.5 cmolkg-1. The physical characteristics of the pedons showed that sand was the dominant soil fraction and this ranged from 30 – 70%. Total clay content ranged from 4 – 10%. Bulk density and total porosity were low in all the pedons and ranged from 1.2 – 1.7 gcm-3 and 13 – 40% respectively. Based on USDA soil taxonomy and information from the physical, chemical and morphological properties of the pedons, the individual soil pedons were classified as Aquic Haplustalfs for Abbi, Aquic Kandiustults for Onicha – Ukwuani and Typic Argia aquolls for Ndemili. Problems identified as limiting factors to land use include excess wetness high electrical conductivity leading to salinity problem and fear of crop submergence due to excessive flooding. Suggested ameliorative or restorative measures for effective land use include drainage system that could reduce excessive wetness, effective fertilizer and liming programmes and cultivation of crops that are saline tolerance and could adapt under anaerobic soil condition.