Abstract

Soil organic carbon (SOC) is an important soil property which relates land-use activities, climate change and soil management to sustainable land-use management practice. But the information on the influence of changes in land-use on SOC stock is lacking. Therefore, this study was conducted during the onset of rainy season in 2017 to investigate the influence of land-use and soil depth on soil carbon stocks located on three land-use types (Arable, Oil palm and Wetland) in two agro-ecological zones in Nigeria. Soil samples were collected at various depths for soil carbon stock study and analysed for physico-chemical properties. The result of the study shows that land-use and soil depth significantly (P<0.05) influenced soil organic carbon stocks which impacted on the ability of the soils located in the different land-use types to sequester carbon. The highest SOC stock was obtained from the Arable land-use (A-LU1 - 24.97 t/ha) Ado-Ekiti, followed by Oil palm plot at Kabba (K-LU3 - 21.06 t/ha) and lastly wetland site at Kabba (K-LU3 - 20.48 t/ha). SOC stock decreased with depth and all land-use types stored higher SOC stock at 0-15 cm depth than any other depth. Soil depth was negatively correlated with SOC stock (r = 0.544) indicating that increase in soil depth is associated with decrease in SOC stock. This study instigated that SOC stock is a function of soil depth, land-use management, soil management practices and location.