Socio-economic benefits of starch crops for biobased plastics: comparison between cassava and sago in Indonesia

Starch remains a popular raw material for biobased plastics. However, the rising demand for biobased plastics raises concerns about its supply and environmental sustainability due to the land required for starch production. In Indonesia, cassava starch is the primary raw material used in biobased plastic production. Sago, an underutilized paludiculture crop, is proposed as a sustainable alternative to cassava starch. In this study, we evaluated the socio-economic benefits of cassava and sago cultivation by examining their financial (farm-level and value-added) and societal impacts. Furthermore, we compared the competitiveness of sago and cassava to maize on mineral soils and oil palms on peatlands.
Our study results show that sago is financially less profitable than cassava per hectare for farmers. The net present value of sago cultivation on peatland is less than one-third of cassava farming on mineral soil. This lower profitability is primarily due to sago's low productivity and the long period required before the first harvest. However, when integrating societal benefits and environmental impacts, starch sourcing from sago is more socially beneficial than cassava, as it generates significantly lower CO₂ emissions. Additionally, long-term sago cultivation can be substantially more profitable than cassava, considering no replanting is needed and optimal yield is achieved. Furthermore, sago offers broader advantages related to peatland restoration programs that support local economic activities, as it does not emit CO₂ during cultivation nor require peat drainage.
This study concludes that as a paludiculture crop, sago can provide a viable feedstock for biomaterials while effectively supporting peatland restoration.