Judul: Utilization of empty fruit bunches and bunch ash oil palm as ameliorant on oil palm (Elaeis guineensis Jacq) seedling growth in main nursery
Abstrak: The objective of the research was to identify the effect of ameliorant to the oil palm seedling growing in main nursery. This experiment was conducted at IPB Experimental Station Cikabayan (Plantation Teaching Farm), Dramaga, Bogor in 250 m above sea level, from November 2011 to May 2012. The experiment was arranged in a randomized block design with seven treatments and six replications. The treatment consist of P1 : Urea 22 g, SP36 15 g and KCl 17,5 g per seedling. P2 : Urea 11 g, SP36 7,5 g and KCl 8,5 g + 1 kg empty fruit bunches per seedling. P3 : Urea 11 g, SP36 7,5 g and KCl 8,5 g + 1 kg bunch ash per seedling, P4: Urea 11 g, SP36 7,5 g and KCl 8,5 g + 1 kg empty fruit bunches + 1kg bunch ash per seedling, P5:1 kg empty fruit bunches + 1 kg bunch ash per seedling, P6:1 kg empty fruit bunches per seedling and, P7:1 kg bunch ash per seedling. The result of the experiment showed that the treatment of P1 : Urea 22 g, SP36 15 g and KCl 17,5 g. P2 : Urea 11 g, SP36 7,5 g and KCl 8,5 g + 1 kg empty fruit bunches. P3 : Urea 11 g, SP36 7,5 g and KCl 8,5 g + 1 kg bunch ash, P4: Urea 11 g, SP36 7,5 g and KCl 8,5 g + 1 kg empty fruit bunches + 1 kg bunch ash having the same affect to the vegetative growth as height respectively, 90,16 cm, 88,03 cm, 87,90 cm and 89,68 cm. The treatment of doses of P4: Urea 11 g, SP36 7,5 g and KCl 8,5 g + 1 kg empty fruit bunches + 1 kg bunch ash, affected to the plant dry weight, roots dry weight respectively 32 % and 36,61 % compare to P1, P2, P3, P5, P6 and P7.
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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: Invers dari Matriks Tridiagonal Jacobi
Abstrak: Suatu matriks berukuran n×n dinamakan matriks tridiagonal jika untuk . Karya ilmiah ini memberikan algoritma yang mudah untuk menemukan invers ( dari matriks tridiagonal Jacobi yang simetrik dan nonsimetrik. Setiap elemen pada matriks tridiagonal ini adalah bilangan real. Terdapat 3 lema dan 2 teorema untuk menentukan . Lema pertama menunjukkan persamaan utama dalam membuktikan lema-lema dan teorema-teorema selanjutnya. Invers dari matriks yang simetrik dibuktikan oleh lema kedua yang menunjukkan elemen-elemen baris ke- dari . Selanjutnya, lema kedua dilengkapi dengan teorema pertama yang menunjukkan elemen-elemen dengan . Invers dari matriks yang nonsimetrik dibuktikan oleh lema ketiga yang menunjukkan elemen-elemen dengan dan elemen-elemen dengan dibuktikankan oleh teorema kedua.
Keyword: symmetric, nonsymmetric, matrix