Growth Dynamics of Oil Palm Seedlings Under Varying Nitrogen Inputs and Watering Frequency During the Pre-Nursery Phase

Optimizing nutrient and water availability is fundamental for producing robust oil palm ( Elaeis guineensis Jacq.) seedlings. This study examined how different urea concentrations and irrigation intervals influence seedling performance during the pre-nursery period. The experiment, conducted from April to July 2022 in Simalingkar B, Medan (±88 m a.s.l.), used a factorial randomized block design consisting of three urea levels (0, 1, and 2 g L⁻¹) and three watering schedules (once every three days, once every two days, and daily), each replicated three times. Growth indicators-including plant height, stem girth, leaf number, leaf dimensions, and leaf area-were recorded weekly until 12 weeks after planting. Urea doses significantly enhanced height and leaf morphological traits, while watering frequency strongly influenced overall canopy expansion. Daily watering and 2 g L⁻¹ urea produced the most vigorous seedlings. No interaction was detected between the two factors, indicating independent modes of action. These results highlight the importance of sufficient nitrogen supply and consistent water availability for producing high-quality oil palm seedlings.