Crop-diversification and organic management increase the energy efficiency of cacao plantations

The increasing global demand for chocolate and related products has intensified their production systems by both replacing traditional agroforestry systems with monocultures and increasing the use of synthetic external inputs and machinery. High dependence on non-renewable energy is a clear symptom of unsustainability in food production systems. Consequently, more sustainable agricultural practices should be promoted. With a special focus on non-renewable energy, this work compares: i) the cumulate energy demand (CED), ii) energy return on investment (EROI), and iii) energy return on labour of four different cacao production systems: two agroforestry systems and two monocultures under organic and conventional management. Cacao and subproduct yields and the use of labour and external inputs were recorded during the first five years after the establishment of the trial in Bolivia. Results show that CED per hectare was almost 2-fold higher in monocultures than in agroforestry systems. With regard to the kilograms of cacao produced, the higher number of inputs used in monocultures was compensated by a higher cacao output. However, when subproducts were also taken into account, non-renewable CED was 7.4times higher in monocultures, and non-renewable EROI increased up to 4.8times in agroforestry systems compared to monocultures. Under organic management, less than 10% of CED was from non-renewable sources, while it reached 75% in conventional systems. Non-renewable EROI was higher under organic management, both when only cacao was considered and when subproducts were also included. Productivity per hour worked and per energy unit of labour invested were both higher in agroforestry systems than in monocultures. In conclusion, diversification of production and organic management are crucial to increase EROI and diminish dependence on non-renewable energy sources of cacao plantations.