Intercropping delivers multidimensional benefits in smallholder agrifood systems: the case of taro–cowpea–maize cultivation in South Pacific Island countries

Introduction Smallholder farming systems in the South Pacific face increasing challenges from climate variability, soil degradation, labour constraints, and poor dietary diversity. Conservation agriculture (CA) has been promoted as a pathway to improve the productivity and resilience of these systems, yet evidence of its economic, social, and climate-adaptation benefits remains limited. Methods This study evaluated a Milpa -inspired taro ( Colocasia esculenta L., Schott)–cowpea ( Vigna unguiculata L., Walp.)–maize ( Zea mays L.) intercropping system in representative smallholder farms in Samoa and Fiji using the Value-Ag integrated assessment framework. Whole-farm profitability, risk, adoption potential, and regional economic impacts under historical conditions and four projected climate scenarios. Food and nutrition security indicators were also assessed. Results and Discussion Model simulations indicated that the CA system was projected to outperform traditional taro monocropping across all climate scenarios. Whole-farm net profit was projected to increase by 67%–73% in Samoa and 55%–63% in Fiji over a 10-year period, driven by enterprise diversification, higher crop and livestock productivity, and reduced input requirements. The CA system was also projected to increase economic return while reducing downside risk, with the greatest relative benefits occurring under hotter and drier climate conditions. Adoption modelling projected peak adoption levels of 17%–54% in Samoa and 28%–50% in Fiji over 18–20 years, resulting in regional profit gains of 4%–14% and 5%–10%, respectively. Energy and protein production were estimated to increase by 73%–275% and 226%–834%, respectively. These results suggest that diversified taro-based intercropping has the potential to improve farm profitability, increase food production, and support climate adaptation in Pacific smallholder farming systems.