Oil palm trunk waste: Environmental impacts and management strategies

The replantation of oil palm in plantations occurs once in every 25 years. Felled oil palm trunk (OPT) is among the most abundant biomass left to decompose naturally in the oil palm plantations. Conversion of this waste biomass can contribute to the booming of secondary industries, which in turn opens up new job opportunities for the local communities. At present, however, OPT is predominantly left in oil palm plantations for soil enrichment purposes. This review aims to discuss the management of OPT waste to ensure the sustainability of oil palm plantations. The OPT has a unique chemical composition with high amounts of carbohydrates and moisture that enhances microbial degradation to release micro and macro nutrients into the soil. Pulverizing and windrowing partially decomposed OPT can help to increase the degradation of OPT. Apart from providing nutrients to the newly planted oil palm seedlings, felled OPT also serves as a breeding ground for pests due to the high carbon to nitrogen ratio which reduces the OPT decomposition rate. As a consequence, disease incidences and severity have been increasing drastically in consecutive replantation. Meanwhile, the removal of felled OPT from the plantation could cause nutrient depletion in the soil and increase fertilizer cost. Therefore, considerable attention from the scientific communities as well the authorities should be given to the management of felled OPT to ensure the sustainable production of oil palm.