Judul: Peningkatan Pertumbuhan dan Hasil Tanaman Gedi (Abelmoschus manihot (L.) Medik.) dengan Aplikasi Pupuk Organik dan Pupuk Anorganik
Abstrak: The objective of this research was to study the effect of organic fertilizer and anorganic fertilizer rate to the growth and yield of gedi (Abelmoschus manihot (L.) Medik.). This research was conducted at Cikabayan Farm, Institut Pertanian Bogor, Indonesia from February to August 2011. The material plant was collected from Sorong, West Papua. The experiment was arranged in Completely Randomized Block Design with fertilizer rate as a single factor treatment. There were eight fertilizer rate treatments such as 0, 20, 40, 60 ton.ha−1 organic fertilizer and 0, 20, 40, 60 ton.ha−1 organic fertilizer + NPK. The organic fertilizer was used chicken manure and anorganic fertilizer NPK 15-15-15. The result of this research showed that using 30.39-34.04 ton.ha-1 of organic fertilizer rate will reached the optimum yield. The optimum rate of organic fertilizer + NPK fertilizer was not determined yet. But, by using of NPK fertilizer could increase the harvest.
Keyword: fertilizer dose, gedi, growth, production

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: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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