Judul: Optimasi pemupukan nitrogen dan kalium terhadap tanaman kelapa sawit di pembibitan utama dan Tanaman Belum Menghasilkan (TBM)
Abstrak: The experiment consist of two experiment, the first experiment was optimizing of Nitrogen and Potassium fertilizer rate for oil palm seedling (Elaeis guineensis Jacq.) on main nursery; and the second experiment was optimizing of Nitrogen and Potassium fertilizers rate on immature plant of oil palm. The purpose of both experiments is to determine the optimum rate of Nitrogen and Potassium fertilizer. The experiment of optimizing Nitrogen and Potassium fertilizer rate for oil palm on main nursery aims to determine the optimum rate of nitrogen and potassium fertilizers was carried out at IPB Experimental Station (Plantation Teaching Farm), Cikabayan Dramaga, Bogor, from May to September 2012. The treatment was laid-out in a factorial randomized block design with three replications. The first factor N.i.e. 0, 25.92, 51.8, and 103.66 N plant-1 and the second was K.i.e 0, 26.99, 53.98 and 107.96 g K2O plant-1. The result of the experiment shows that Nitrogen and Potassium fertilizer increase the plant height, number of frond and stem diameter. Base on the plant height the optimum dose of Nitrogen fertilizer is 67.70 g and Potassium fertilizer is 86.68 during five months in the main nursery. The objectif of the experiment optimizing of Nitrogen and Potassium fertilizer rate for oil palm on immature was to determine the optimum rate of Nitrogen and Potassium fertilizers. Experiment was conducted at IPB Experimental Station (Plantation Teaching Farm), Singasari Jonggol, Bogor, from February to June 2013. The treatment was laid-out in a factorial randomized block design with three replications. The experiment was conducted in two trials, the first trial is made up of four Nitrogen fertilization levels N.i.e. 45, 90, 135, and 180 g N plant-1. The result shows that Nitrogen in immature increase 12.88 (cm month-1) of growth of the plant height, 3.75 (sheet month-1) of number of fronds, 3.46 (cm month-1 ) of stem girth and 3.16 (cm2 month-1 ) of leaflet area. The second is Potassium fertilization trial consist of four levels K.i.e. 30, 60, 90, dan 120 g K2O plant-1. The result shows that Potassium in immature increase 12.83 (cm month-1) of growth of the plant height, 3.61 (sheet month-1) of number of fronds, 4.03(cm month-1 ) of stem girth and 2.61 (cm2 month-1 ) of leaflet area.
Keyword: Potassium., Nitrogen, main nursery, optimizing fertilizer rate, oil palm seedling, oil palm immature plant

Judul: Optimasi dosis nitrogen dan kalium pada bibit kelapa Sawit ( Elaeis guenensis Jacq) di Pembibitan Utama
Abstrak: The need of oil palm seedlings increase with the growing demand from farmers and plantation companies. The use of high quality seedlings is one of the requirements to obtain a high productivity. Thus the proper fertilization of seedlings planted at the main nursery should be done. This research aimed to determine the growth response of oil palm seedlings to various doses and to determine the optimum dose of nitrogen and potassium fertilizer on oil palm seedlings. The experiment was carried out at Cikabayan Experimental Station at IPB Darmaga Campus, Bogor, West Java. The experimental design used was factorial randomized block design with three replications. The treatment consisted of two factors, the first factor was N fertilizer and the second factor was K fertilizer. N fertilizer consists of four levels ( N1 = 0 g, N2 = 8.35 g, N3 = 16.7 and N4 = 33.4 g/seedling) and K fertilizer consists of four levels ( K1 = 0 g, K2 = 10.9 g , K3 = 21.8 g, and K4 = 43.6 g/seedling). The result of the experiment shows that N and K fertilizer increase the plant height, number of frond and stem diameter. Base on the plant height, the optimum dose of N fertilizer is 22.27 g and K fertilizer is 35.13 g during six months in the main nursery.
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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