Agronomy explains large yield gaps in smallholder oil palm fields

CONTEXT: Palm oil production is a major source of income for millions of smallholders in Indonesia. However, actual yield remains low in relation to the attainable yield. While emphasis has been given to planting material as a factor explaining low yield in smallholder fields, the role of agronomic management has received less attention. OBJECTIVE: We assessed the role of agronomic management in explaining low oil palm productivity in independent smallholder fields in Indonesia. METHODS: We quantified yield gaps and their causes using data on fresh fruit bunch (FFB) yield and management practices collected over two years across 977 fields. The yield gap was estimated for each field as the difference between actual and attainable yield. The latter was estimated using a crop model, local weather and field-specific soil and palm age. Statistical techniques were used to identify factors explaining yield gaps. RESULTS AND CONCLUSIONS: Average yield represented 42% of the attainable yield, with largest yield gaps occurring in young plantations. Our analyses identified agronomic practices explaining yield gaps, including nutrient management, harvest interval, weed control, and pruning. Improved agronomic management can help smallholders increase yield and profit on existing plantations. SIGNIFICANCE: There is an opportunity to produce more palm oil on current plantation area via better agronomy, generating a positive economic impact at local to national levels, while reducing pressure to clear new land for cultivation. Research & extension programs should be re-oriented to give more emphasis to agronomic management.