Nutritional imbalance in smallholder oil palm plantations in Indonesia

Oil palm (Elaeis guineensis Jacq.) is an exceptionally efficient producer of vegetable oil. Its potential production is estimated to be well over 10 tons of oil per hectare per year, at least three times more than the second most efficient vegetable oil producer, canola. The cultivation of oil palm provides a steady source of income for both plantation companies and smallholders. In Indonesia, the world’s largest oil palm producing country, around 45% of the area under oil palm is owned by smallholders. The majority of the smallholders manage their plantations individually, applying inputs and implementing management practices as they see fit. Yields in smallholder plantations are estimated to be 3-4 tons of oil per hectare, which is lower than company owned plantations and far less than the production potential. Poor fertilizer application practices come up in many studies as a key problem in smallholder systems. Farmers tend to over-apply cheap nutrients (especially N) and under-apply the more expensive ones (especially K), leading to nutritional imbalance. There are several obvious solutions to improve plant nutrition, but the implementation of these solutions in the complicated socio-economic context of the smallholders is challenging