NITROGEN UPTAKE MODEL OF OIL PALM IN MAIN NURSERY

Optimising the use of nitrogen (N) fertiliser in the main nursery will save costs, optimise seedling growth, and minimise N leaching. Appropriate N fertiliser recommendations can be approached by modelling growth and nitrogen uptake. This study aimed to obtain a model of nitrogen uptake from oil palm seedlings in the main nurseries. The trial was conducted at the Leuwikopo Experimental Farm, IPB University, from May 2021-January 2022. The experiment consisted of five levels of N replicated five times. Treatments N0, N1, N2, N3 and N4 consisted of 0%, 50%, 100%, 150% and 200% standard fertiliser, respectively. The developed growth and N uptake model can only be used to predict oil palm growth and nutrient uptake in the main nurseries. The model was built from the dry matter partition coefficient, nutrient partition coefficient, and the actual amount of nutrient requirement. The model validation results during the main nursery showed that the model developed generally corresponded to the observed values for dry weight and nutrient uptake in the field. The developed model can predict oil palm seedlings’ dry weight and nutrient uptake in the main nurseries under various conditions of deficiency or excess of N fertiliser level and climate conditions.