Analysis of phosphorus and potassium leaves uptake of immature palm oil smallholder plantation in Lamandau regency, central Kalimantan on fertilization through axil

Abstract

Nutrient management in immature smallholder oil palm plantations remains a major challenge due to low soil fertility and high nutrient losses, particularly for phosphorus (P) and potassium (K). Conventional soil application often results in low uptake efficiency, limiting plant growth and productivity. This study aimed to evaluate the effectiveness of fertilizer application through the axils on P and K uptake in immature smallholder oil palm. The research was conducted in Lamandau , Central Kalimantan, Indonesia, at an altitude between 90.08 to 153.2 meters above sea level, a type of red and yellow podzolic soil, an average rainfall of 191.4 mm/year and daily air temperature between 23°C to 32°C throughout the year. Randomized complete block design used with different MKP fertilizer dosages namely 226 g and 75 g/tree applied directly into the axils and 226 g/tree applied to the soil. Leaf samples were analysed for P and K concentrations, while soil nutrient status were also assessed. The results showed that the uptake of phosphorus and potassium in MKP fertilization at a dose of 75 g/tree and 226 g/tree through the axil was relatively the same as through the soil at a dose of 226 g/tree. It can be concluded that MKP fertilization through the axil is more effective than through soil even at the lowest dose. These findings suggest that frond axil fertilization is a promising strategy to optimize nutrient management in smallholder oil palm plantations, particularly on marginal soils in Central Kalimantan. The adoption of this method has the potential to improve sustainability and productivity in smallholder oil palm systems.