Life Cycle Greenhouse Gas Balances and Economic Trade-Offs of Oil Palm-Cassava Intercropping: A 25-Year Retrospective Assessment

Abstract

Sustainable agriculture in Southeast Asia requires balancing economic viability with climate mitigation. This study investigated whether integrated intercropping can mitigate early-stage economic “dead zones” in perennial crops while simultaneously enhancing long-term carbon sequestration. A 25-year bio-economic simulation in Thailand compared three scenarios: oil palm monoculture (OPM), cassava monoculture (CM), and cassava-oil palm intercropping (COPI) during the initial 5-year establishment phase. Secondary national data were analyzed to quantify crop yields, carbon footprint, carbon sequestration, and inclusive income (incorporating crop revenues, self-employment wages, and potential carbon credits). Results demonstrate that COPI and OPM achieve identical accumulated carbon sequestration (−389.50 tCO2eq/ha with the same number of palm plants, with carbon footprints of 65.07 and 63.57 tCO2eq/ha, respectively (CM: 30.78 tCO2eq/ha)). Economically, COPI successfully bridges early-stage cash deficits, achieving the highest cumulative inclusive income (2.95 × 106 THB/ha) and commercial profit (2.93 ×106 THB/ha), outperforming OPM (2.78 × 106 THB/ha and 2.77 × 106 THB/ha) and CM (2.91 × 106 THB/ha for both). Although OPM yields a slightly higher net cash flow (0.77 × 106 THB/ha vs. COPI’s 0.74 × 106 THB/ha), COPI optimizes smallholder livelihood stability via retained household self-employment wages. Overall, integrated intercropping improves smallholder climate resilience and financial stability, providing a scalable model for sustainable tropical agriculture.