Judul: Penggunaan Pupuk Organik Cair Untuk Mengurangi Dosis Penggunaan Pupuk Anorganik Pada Padi Sawah (Oryza sativa L.)
Abstrak: Use Of Organik Liquid Fertilizer For Reducing The Dose of Inorganik Fertilizer Use in Paddy Rice Fields. This research started from Oktober 2009 until Februari 2010, located in Desa Situgede, Kecamatan Bogor Barat. This research Used One Faktor Randomize Complete Block Design with three times aplication. The treatment of liquid organik fertilizer kinds I and II in combination with NPK fertilizer capable of providing growth and yield of rice which is bigger then not significantly with just the NPK treatment. Eventough, several liquid organik fertilizer treatment agronomicaly efectif. It is means, organik liquid fertilizer can increase the paddy yield, eventhough not statistic significantly and potential to reduce the dosis of NPK anorganik fertilizer.
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Judul: Optimasi Dosis Pupuk Organik yang Diaplikasikan dengan Pupuk Hayati pada Budidaya Padi Organik
Abstrak: The research was conducted at Cibungur, Karawang Wetan, Karawang. Soil analysis carried out at the soil Laboratory, Department of Soil Science and Land Resources, agriculture faculty of IPB. The research was conducted from December 2012 to March 2013. The research design used was Randomized Plots Divided (Split Plot Randomized Block design). This research using a factorial design with two factors, namely bio-fertilizers and organic fertilizers. Data analysis using analysis of variance (F test), if real then by DMRT (Duncan Multiple Range Test) at the level of 5%. Treatment consisted of two biological fertilizer levels that is 2 l ha-1 application-1 and 0 l aplikasi-1 ha-1. Treatment of solid organic fertilizer consist of six levels, namely: 0 ton ha-1, 2 ton ha-1, 4 ton ha-1, 6 ton ha-1, 8 ton ha-1, and 10 ton ha-1 . The purpose of this study was to determine the effect of a combination of organic fertilizer with bio-fertilizers on organic rice farming. Applications POP 10 ton ha-1 resulted height plant, biomass plant, 1000 grain weight, GKP and GKG highest to all treatments. Application POP 8 and 10 ton ha-1 combined with bio-fertilizers can increase the yield of 6 and 10% grain yield, while treatment 2-6 ton ha-1 dont improve outcomes compared with control. POP dose 8-10 ton ha-1 increase grain yield around 10%.
Keyword: organic rice, organic fertilizers, bio-fertilizers

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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