Carbon Stocks in Two Colombian Oil Palm Agroecosystems: Variations in Age Gradients and Cultivar Type

Perennial crops such as oil palm contribute to carbon (C) storage through the accumulation of biomass and soil organic carbon (SOC). This observational, cross-sectional study was conducted at two Cenipalma experimental research stations in Colombia and evaluated variations in carbon stocks across four plantation age classes (≤5, 6–10, 11–15, and >15 years) and two cultivar types (Elaeis guineensis and the OxG interspecific hybrid), with 40 palms evaluated at each study site. Carbon stocks were assessed through field measurements and soil analyses by integrating aboveground biomass (AGB), belowground biomass (BGB), companion vegetation, and SOC. In addition, a sensitivity analysis was performed to assess palm-to-palm replanting under the Cropland Remaining Cropland framework, incorporating existing SOC stocks and residual biomass from the previous production cycle using literature-derived decomposition and humification parameters. Results showed an increasing pattern in biomass carbon accumulation across plantation age classes, while differences between genetic materials became more evident at advanced developmental stages. Total agroecosystem carbon stocks ranged from 99 to 169 t C ha−1 at CEPC and from 141 to 188 t C ha−1 at CEPV, with SOC representing the largest carbon pool. The sensitivity analysis generated model-derived estimates of residual carbon remaining 24 months after replanting, providing complementary information on the potential contribution of legacy biomass to subsequent carbon stocks. Overall, these findings emphasize the importance of integrating biomass, soil, and legacy carbon pools when assessing carbon storage in oil palm agroecosystems.