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 pupuk nitrogen dan fosfor pada bibit kelapa sawit (Elaeis guineensis Jacq.) di pembibitan utama
Abstrak: The objective of this experiment was to study the optimum doses fertilizer of Nitrogen and Phosphorus for oil palm seedling (Elaeis guineensis Jacq.) in main nursery. This experiment was carried out at IPB Experimental Station (Plantation Teaching Farm),Cikabayan Dramaga, Bogor, from November 2011 to May 2012. The treatment was laid-out in a factorial randomized block design with three replications. The first factor was N i.e. 0, 8.51, 17.02, and 34.04 g N.plant-1 and the second was P i.e. 0, 2.28, 4.56 and 9.12 g P.plant-1. The result of the experiment showed that vegetative growth increased with fertilizer application. The height and leaf area of plant are affected by interaction between N and P significantly. The total leaf number and steam diameter increased quadratically with fertilizer rate of N and application of P increased linearly. Base on the height of plant and leaf number, optimum recommendation rate of N for oil palm seedling during six months in main nursery is 21.99 g N plant-1, by aplication every month i.e. 1.60, 1.14, 2.80, 4.01, 5.73 and 5.74 g N plant-1.month-1. Optimum recommendation rate of P is 4.24 g P plant-1 by aplication every month i.e. 0.22, 0.44, 0.76, 0.18, 0.94, and 1.70 g P.plant-1.month-1. The seedlings that resulted from experiment could be requisite accomplished to used on commercial planting.
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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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