Judul: The role of organic fertilizer to increase the effectivity of NPK fertilizer for oil palm seedling (Elaeis guineensis Jacq.)
Abstrak: Oil palm has higher palm oil productivity than the others. So that, the precision plantation technology of oil palm cultivation must be done in order to preserve high productivity of oil palm. A seedling is the first step that affecting for oil palm’s age and productivity. Good growth will produce high quality and production of oil palm. The necessity of oil palm seedlings to intensify areal and replant would grow continuously, so it has needed to obtain precise fertilization. The objectives of this experiment were (1) to obtain the best organic-NPK fertilizer combination in increasing the effectiveness of the use of NPK fertilizer, (2) to study the role of organic fertilizer for the growth of oil palm seedling in main nursery, and (3) to investigate the efficiency of NPK fertilizer for best combination. The experiment was conducted from December 2011 to September 2012 at IPB Teaching Farm Dramaga Bogor. The layout was arranged in a factorial random block design with three replications. The first factor was volume ratio organic fertilizer to top soil i.e 0, 1:6, 2:6, and 3:6. The second was NPK Fertilizer rates i.e 0.0, 127.5, 255.0, and 382.5 g NPK.plant-1. Each of treatments have 5 plants, so that the numbers of sample were 240 plants. The result showed that combination of organic and NPK fertilizer significantly affected to plant height, leaf number, steam diameter, leaf area, and chlorophyll content. The interaction between organic and NPK fertilizer significantly affected to plant height at 8 Months After Transplanting (MAT)), leaf number (5-8 MAT), steam diameter (8 MAT), leaf area (3 MAT) and chlorophyll number (4 MAT). Organic fertilizer had increased the effectiveness of NPK fertilizer for oil palm seedlings, in this research the highest effective value was organic fertilizer 2:6 (organic fertilizer : top soil) and NPK 382.5 g plant-1 with the effective value was 179.38%. The only application of organic fertilizer 3:6 has showed oil palm seedling that no significant with NPK application from 127.5-382.5 g tanaman-1 without organic fertilizer. So that, organic fertilizer 3:6 could be substituted of NPK fertilizer. The best combination treatment was 2:6 and 382.5 NPK g plant-1 with effective value was 158.91%, 209.14% and 170.10% for plant height, leaf number and stem diameter, respectively. Organic fertilizer had increased the efficiency of NPK fertilizer with absorption rates of N, P and K was 56.16%, 11.06% and 29.90%.
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Judul: Optimizing of fertilizer nitrogen and phosphorus doses for oil palm seedling (Elaeis guineensis Jacq.) in Main Nursery
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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