ABSTRACT:

Organic matter fractionation revealed different pools of organic carbon sequestration in the soil. Investigation of organic matter pools are important for proper management of soil fertility and stability of soil aggregate. Research was carried out on variability in persistence of organic matter pools and is relationship with soil properties on two parent materials (sandstone/shale and coastal plain sand) in Akwa Ibom State, Nigeria. Soil samples were collected in eighteen locations in each of the parent material giving a total of thirty-six soil samples and were analysed for physical and chemical properties of the soil. Data generated were fitted into empirical models for computation of physical and chemical properties, and organic matter fractions. The result indicates that sand fraction dominant particle size distribution in the two parent materials. Furthermore, among the two parent materials, sandstone/shale had the least mean value in humins and humic acid while coastal plain sand had the least mean value in fulvic acid. Correlation analysis for sandstone/shale parent material shows that total sand correlated positively with humins (0.479*) and humic acid (0.536*). Bulk density correlated negatively with total porosity (-0.999*), while hydraulic conductivity correlated positively with potassium (0.516*) and sodium (0.508*). pH correlated negatively with exchangeable acidity (-0.498*). The results for coastal plain sand parent material shows that clay was correlated negatively with calcium (-0.442*) and positively with humins (0.404*), while humins correlated positively with humic acid (0.466*) and fulvic acid (0.903**). pH negatively correlated with calcium (-0.413*). This could be used to develop management frame work practices in the studied soils that would improve soil health