MPOB Technology No. 30 : Modelling Oil Palm Nutrient Demand, Nutrient Turnover and Nutrient Balance
The MPOB Technology series contains technical articles on specific aspects of the compoaition, properties, processing, refining, and end-uses of palm oil. It also covers oil palm technology
OPRODSIM (Oil Palm Production Simulator) is a source-based model that simulates fresh fruit bunch (FFB) yield based on the assimilate remaining after the requirements of vegetative growth have been met. In its initial form, the model assumes that nutrient supply is non-limiting. In this report, the ‘demands’ for the major nutrients (nitrogen, phosphorus and potassium) needed to achieve ‘satisfactory’ yields of oil palm are considered, and equations to calculate these are incorporated in an updated version of the model. A nutrient balance is developed that takes account of nutrient uptake and storage in permanent biomass, nutrient export in FFB, nutrient turnover within the plantation, nutrient inputs by rain, legume covers and mill by-products, and nutrient losses by leaching and other processes. Some uncertainties are identified such as the fate of nutrients in cut frond bases and decaying male inflorescences. Nutrient budgets are presented and the results are compared with those from field experiments.