Judul: The Effect of Sengon (Falcataria moluccana) Shade and Organic Fertilizer on Arrowroot Growth (Maranta arundinacea)
Abstrak: Agroforestri merupakan pengombinasian tanaman kehutanan (pepohonan) dengan tanaman pertanian yang dapat dilakukan secara bersamaan (pengaturan ruang) atau bergiliran (pengaturan waktu). Garut (M. arundinacea) merupakan salah satu tanaman pangan fungsional yang mampu beradaptasi dan tumbuh secara optimum di bawah naungan sehingga dapat dikombinasikan dengan sengon (F. moluccana) dalam sistem agroforestri. Tujuan penelitian ini adalah mengukur pertumbuhan Sengon Solomon F2 dalam sistem agroforestri, serta mengetahui pengaruh naungan sengon dan jenis pupuk organik terhadap pertumbuhan dan produktivitas garut. Penelitian ini menggunakan pupuk kandang sapi dan pupuk organik hayati (POH). Hasil penelitian menunjukkan pertumbuhan Sengon Solomon F2 yang berumur 3 tahun selama 5 bulan mengalami kenaikan tetapi tidak signifikan. Naungan sengon memberikan pengaruh yang nyata terhadap pertumbuhan garut dan produksi umbi yang dihasilkan, sedangkan jenis pupuk organik tidak memberikan pengaruh yang nyata. Pertumbuhan tanaman garut terbaik terdapat pada perlakuan tanpa naungan sengon dengan pemberian pupuk kandang sapi yang menghasilkan produksi umbi rata-rata sebesar 325,60 g/polybag, sehingga menghasilkan produktivitas sebesar 2,5 ton/ha.
Keyword: agroforestry, functional food, light intensity, manure, sengon

Judul: Pengaruh Pupuk Organik dan Anorganik pada Tanaman Garut (Marantha arudinaceae L.) di bawah Tegakan Sengon (Falcataria moluccana Miq.)
Abstrak: Increased population is one of the factor that increase the land conversion rate, both in forest and agriculture land. Agroforestry systems can be a solution for increased need of agricultural land. Agroforestry combine forest stand with agricultural plant. Kind of the forest stand that start to be cultivated was sengon stand combined with agricultural plant was arrowroot (M. arudinaceae). Production of arrowroot can be improved by anorganic or organic fertilizers. The objective of this research is to observe growth of arrowroot plant under the stand of sengon, to observe the influence from type and dose of fertilizer, and to determine the best dose for each type of fertilizer which influence plant to produce the best arrowroot. The parameters observed from arrowroot plant are percent survival, height, leaf width, leaf length, number of leaves, number of roots and roots weight. The organic fertilizer gave significantly effect to height and number of leaves on the dose of fertilizer 1 400 mL/ha. While the anorganic fertilizer gave significant effect to height, number of leaves, and roots weight on the dose of fertilizer 60 kg/ha.
Keyword: sengon, organic fertilize, arrowroot, anorganic fertilize, agroforestry

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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