Long-Term Cultivation of Perennial Energy Crops Enhance Ecosystem Multifunctionality on Marginal Red Soil Without Trade-Offs

Abstract

Perennial energy crops (PECs) are increasingly being recommended for cultivation on marginal lands to support the bioeconomy and promote soil restoration, owing to their low input requirements and large potential for soil organic carbon sequestration. However, the effects of the cultivation of PECs on the trade-offs or synergies among soil functions, and consequently on ecosystem multifunctionality (EMF), remain unclear, hindering large-scale adoption. We conducted our measurements in a long-term field experiment that was established a decade ago, where Miscanthus and switchgrass were cultivated alongside a native C₃ grass mixture (Cyperus rotundus L. and Setaria viridis L.) as reference to assess the effects of PECs on soil multifunctionality. We assessed 10 ecosystem functions grouped into provisioning, supporting, and regulating services. The results demonstrate that Miscanthus and switchgrass cultivation elevated the overall EMF by an average of 5.29-fold over the C₃ native grass control, with supporting, regulating, and provisioning services increasing by 2.08, 7.27, and 43.98-fold, respectively. Specifically, the two PECs improved all 10 measured soil functions, with the exception of abiotic stress regulation under switchgrass cultivation. Miscanthus outperformed switchgrass by 41.54% in supporting services and 81.09% in provisioning services, resulting in higher EMF. Moreover, strong positive relationships were observed among the three service categories, indicating that the cultivation of PECs improves EMF consistently without significant trade-offs. These findings suggest that cultivating PECs on marginal land can simultaneously provide sustainable biomass feedstock and enhance soil health, supporting the feasibility for larger-scale deployment.