ASSESSEMENT OF THE BASELINE DISTRIBUTION OF ORGANIC CARBON IN SOILS OF ESAN SOUTH EAST LOCAL GOVERNMENT AREA OF EDO STATE, SOUTHERN NIGERIA

The knowledge of spatial distribution of soil organic carbon is an important requirement for understanding the role of soils in the global carbon system. In this study, soil samples were obtained from the land of different uses in Esan South East Local Government Area, Edo State, South-South Nigeria, in order to determine the forms and spatial distribution of organic carbon content of the soils. The soils were collected from 0 – 15cm (topsoil) and 15 – 30cm (subsoil) depths. The soil samples were physically fractionated into labile organic carbon fraction and recalcitrant organic carbon fraction following standard methods. Selected physiochemical properties of the soils were also determined and the results obtained were subjected to statistical analyses. The result showed that the labile organic carbon fraction accounted for 15 percent of the total organic carbons while the recalcitrant organic carbon fraction accounted for 85 percent indicating that the recalcitrant organic carbon fraction is of a greater proportion than the labile organic carbon fraction. These fractions were found to be decreasing also with the depth. The soil organic carbon is also low. The study also shows that the different land uses contributed to the relatively low levels labile organic carbon in the soil hence appropriate crop and soil management practices are required in maintaining or improving the organic carbon status of the soil.