Impact of Land Use Systems and Parent Materials on Soil Quality Indicators in Soils of Akwa Ibom State, Nigeria

A study on the impact of parent materials and land use on soil quality indicators in soils of Akwa Ibom State was conducted. The aim was to evaluate the impact of parent materials and land use systems on soil quality indicators. Three parent materials (coastal plain sand, sandstone/shale, and beach ridge sand) and three land use types (cultivated land, fallow land of 3–5 years, and oil palm plantation) were selected for the study. In each land use type per parent material, six composite soil samples were collected from the representative location within the three land use types using soil auger within 0–30 cm soil depth. Undisturbed core samples were also collected for bulk density and saturated hydraulic conductivity determinations. A total of 52 soil samples were generated for laboratory analysis. Results showed that among the parent materials, coastal plain sand soil had the highest silt + clay fraction, organic matter, total N, available P, and exchangeable K, followed by sandstone/shale while beach ridge sand soil had the least. Among the land use types, oil palm plantation had the highest silt + clay fraction, organic matter, exchangeable Ca and K, followed by fallow land while cultivated land had the least. The combination of parent material and land use indicated that cultivated, fallow and oil palm plantation of coastal plain sand soils had the highest water and nutrient holding capacity, high rooting volume, good aeration status, less erosion threat, higher exchange sites, more available nutrients for plant uptake, more biological activity, etc., followed by sandstone/shale while beach ridge sand had the least in the study area. The application of more organic and less inorganic fertilizers will improve the soil quality of the study area.