Shortening harvest interval, reaping benefits? A study on harvest practices in oil palm smallholder farming systems in Indonesia

CONTEXT: Smallholders are responsible for a large share of global palm oil production. Yet, in Indonesia, the main palm oil producing country, smallholders' yields remain low. Better management practices, including short harvest interval (HI, the number of days between two harvest rounds), could help to raise smallholder yields. However, at present, HI is long in smallholder fields and the drivers underlying this phenomenon are poorly understood. OBJECTIVE: We explored agronomic, socio-economic, and institutional factors that underlie harvesting practices in independent oil palm smallholder farming systems in Indonesia to assess scope for sustainable intensification through shorter HI and reduced harvest losses. METHODS: Combining methods from agronomy and anthropology, we followed harvest interval of 950 farmers in six representative locations across Indonesia via farmer diaries over a period of two years to establish a correlation with yield. To quantify this relationship, we conducted post-harvest field measurements, and to explain which underlying factors impact HI we did qualitative interviews and surveys. RESULTS AND CONCLUSIONS: The HI of smallholders in our study ranged from 10 to 39 days (average: 17-d). Half of the farmers followed long HI (>16-d). Key factors impacting HI include annual fresh fruit bunch (FFB) yield, total palm area per farmer, trusted labor availability, plantation accessibility, and FFB price. Farmers responded to low yield by prolonging HI to increase labor productivity and optimize labor and transportation costs. SIGNIFICANCE: This study contributes to a better understanding of the relation between HI and yield in smallholder farming systems, by uncovering how socio-economic and institutional factors sometimes override agronomic considerations. Long HI can potentially lead to harvest loss from loose fruits and missed bunches, and reduce oil quality from overripe bunches. However, to obtain the benefits of shorter HI requires collectiv