Asian Journal of Applied Sciences (ISSN: 2321 – 0893) Volume 03 – Issue 03, June 2015 Asian Online Journals (www.ajouronline.com ) 375 Optimization Rate of Organic and NPK Compound Fertilizers on Second Year Immature Oil Palm Adinda N. H. Manurung 1* , Sudradjat 2 , Hariyadi 2 1 Graduated student of Bogor Agricultural University, Indonesia 2 Lecturer of Bogor Agricultural University, Indonesia * Corresponding author’s email: adinda.nhm [AT] gmail.com ____________________________________________________________________________________________________________ ABSTRACT---- Oil palm is a potential vegetable oil producer and its productivity needs to increase. This experiment aimed to determine the optimum rate of organic and NPK compound fertilizer on second year immature oil palm. Morphological and physiological observation yearly found the optimization rate. Organic fertilizer did not affect plant height, trunk girth, leaf area, NAR, chlorophyll, and N, P, K leaf content significantly. NPK fertilizer affected plant height, trunk girth, leaf area, NAR, chlorophyll, and N, P, K leaf content significantly. The optimization rate for second year immature palm oil is 3.52 kg NPK compound fertilizer plant -1 year -1 and optimization rate for organic fertilizer could not be determined in this experiment. Keywords--- cow manure, nutrient level, vegetative growth _________________________________________________________________________________________________ 1. INTRODUCTION Palm oil is a potential plant and has high economic value. In 2014, world consumption of vegetable oils increased 8.4 times compared to 1980. World consumption of vegetable oil in 2014 was 151.6 billion tons. Palm oil occupies the largest edible oil consumption 41% and outperformed dominance soybean oil (GAPKI, 2014). Indonesian palm oil productivity is only 3-4 tons ha -1 , while the productivity potential can reach up to 6 tons of Crude Palm Oil (CPO) (Goenadi, 2008). Oil palm national productivity is low caused by low productivity of smallholder plantations. According to World Growth (2011), 41% of Indonesia's oil palm plantations owned by smallholder. The lack of knowledge in oil palm cultivation techniques is the reason of low productivity. Compound fertilizer usage is more practical in application and labor-saving appropriate to be applied in smallholder agriculture. Application of compound fertilizers generally showed better results than the standard single fertilizer application (PTPN III, 2007). Fertilization is an important aspect when palm oil being cultivated on soils with low physical and chemical fertility. Proper fertilization will support the productivity of oil palm hybrids which are generally very responsive to fertilization (Hakim, 2007). However, fertilization is required the greatest cost in the cultivation of oil palm. Fertilization requires 40% - 60% of maintenance cost, or about 20% of the total cost of production (Waluyo et al. 2012). The aim of fertilization optimization is to decrease production costs. The principle of optimization is fertilizer application in accordance with the target result to be achieved and still maintaining soil fertility status. Fertilization aspects need to be considered since the immature period. During this period, palm requires more intensive maintenance. In addition, Better growth during the immature period will accelerate and increase production in the mature period (Santoso and Widiastuti, 2011). This experiment is a sequel research which based on previous research conducted by Siallagan et al. (2014). Siallagan et al. (2014), found that the interaction of cow manure and NPK compound in the first year oil palm has a significant effect on the trunk girth, plant height and leaf nitrogen and phosphorus levels. The optimum rate for first year immature oil palm was 1.9 kg NPK compound and 40.7 kg organic fertilizer plant -1 year -1 . This experiment aimed to determine the optimum rate of organic fertilizer and compound NPK fertilizer on second year immature oil palm. 2. MATERIALS AND METHODS 2.1 Experimental Site The experiment was conducted at IPB-Cargill Oil palm Teaching Farm, Jonggol, Bogor, West Java - Indonesia, with