Indication of Soil Organic Carbon Augmentation in Oil Palm Cultivated Inland Mineral Soils of Peninsular Malaysia

Abstract

Studies conducted on soil organic carbon (SOC) along with the annual soil fertility testing indicate that the carbon (C) stored or sequestrated in the soil was higher in the second and third cycles by 32 and 47 per cent, respectively than the first cycle of oil palm cultivation developed from the logged jungle of inland soils of Peninsular Malaysia. Although the SOC values of the top soil (0-15 cm) was higher than that of subsoil (15-45 cm), the largest build-up of SOC was observed at a depth of 15-45 cm in the second and third cycles of oil palm cultivation, indicating that the below-ground biomass of preceding planting contributes to a greater sequestration of carbon in the soil. Nevertheless, deviation from the mean SOC was broad which could be due to the temporal changes in the methods of planting and re-planting, palm age, field management practices of maintaining inter-row vegetation, pruning, placement and amount of fronds, disease control and placement of wastes from the oil mill. It appears that in the life cycle assessment of oil palm, where land uses and land use change ( LULUC) is considered, it may be essential to look into SOC as a part of the measuring tool of C stock prior to the development of oil palm and the increment of C stocks in each cycle of cultivation. Keywords: Soil organic carbon, soil carbon sequestration.