Soil organic carbon sequestration rate and spatiotemporal dynamics under perennial energy crops cultivation: A global meta-analysis

Cultivating perennial energy crops (PECs) not only enhances soil organic carbon (SOC) sequestration but also provides a reliable feedstock for bioenergy production. Nevertheless, the lack of exploration of the SOC sequestration rate and its spatiotemporal dynamics at a global scale hinders the industrial-scale implementation of PECs cultivation. In this study, we conducted a comprehensive global meta-analysis to quantify the SOC sequestration rate and elucidate its spatiotemporal dynamics. The results showed that PECs cultivation globally achieves a SOC sequestration rate of 0.21 Mg ha (-1) yr (-1). The crop age and soil depth were identified as the most important driving factors of the SOC sequestration rate. The SOC sequestration rate of PECs cultivation initially increased with crop age but eventually declined, reaching its peak at 9 years. Notably, the SOC sequestration rate was higher in deeper soil layers, particularly within 30-60 cm, compared to the topsoils (0-30 cm). Our results provide compelling evidence that PECs have promising potential for enhancing SOC sequestration, particularly in deep soils over the long term. These results contribute to the formulation of relevant policies aimed at effectively deploying PECs to facilitate the transition to renewable energy sources and achieve carbon neutrality.