Judul: Optimalisasi Pertumbuhan dan Produktivitas Jarak Pagar (Jatropha curcas L.) Melalui Aplikasi Pemupukan.
Abstrak: The study was conducted to determine the effect of fertilizer application (dose and time) on the growth and productivity of jatropha. Research conducted at PT. Indocement, Citeureup, Bogor regency in October 2010 - July 2011. This research using randomized complete block design (RCBD) two factors. The first factor is the dose of fertilizer, which consists of five levels, namely 0, 24, 36, 48, and 60 g / plant. The second factor is the time of fertilization, namely 2 and 14 week after transplanting (WAT). Type of fertilizer used is NPK fertilizer, with a ratio of 15:15:15. Data obtained from observations processed using various analysis (ANOVA). Observations made in the vegetative phase of growth (plant height, leaf number, number of branches, and trunk diameter) and the generative phase (the number of productive branches, number of panicles, number of fruits, fruit weight, seed number and seed dry weight). Most of the dose of fertilization no significant effect on plant growth vegetative phase, except in the number of primary branches in 12 WAT. Significantly affect the dose of fertilization treatment increased the number of fruit and branches of productive. In general, from several observation variables (plant height, stem diameter, number of fruit, and productive branch) 48g/tanaman dose treatment tended to give better results. Fertilizer at 14 WAT is more effective, because it can have any number of fruit, fruit weight, seed number and seed dry weights were markedly higher than the 2 WAT treatment.
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Judul: Pertumbuhan Vegetatif Dan Produksi Tanaman Jarak (Jatropha Curcas L.) Pada Berbagai Taraf Dosis Pupnk Nitrogen Dan Kalium
Abstrak: Penelitian ini dilakukan untuk mengetahui pengaruh pemupukan nitrogen dan kalium serta interaksinya pada pertumbuhan dan produksi tanaman jarak (Jatropha curcas L.). Penelitian dilaksanakan di Kebun Cikarawang, Darmaga, Bogor dari bulan Desember 2005 sampai bulan Mei 2006. Penelitian ini menggunakan raneangan faktorial dalam lingkungan Aeak Kelompok (RAK). Perlakuan terdiri dari dna faktor yaitu pemupukan N dan pemupukan K. Pemupukan N terdiri dari 4 taraf yaitu 0 kg Nlha (No), 64 kg Nlha (N I), 128 kg N/ha (N2), 256 kg Nlha (N3). Pemupukan K terdiri atas 3 taraf yaitu o kg K20lha (Ko), 60 kg K20 Iha (KI), 120 kg K20 Iha (K2). Setiap tanaman dipupuk P dengan dosis 72 kg P20slha. Tiap perlakuan diulang tiga kali sehingga terdapat 36 satuan pereobaan. Penyemaian dilakukan pada polybag ukuran 15 em x 20 em. Penelitian ini dilakukan pada lahan seluas 1300 m2 yang dibagi menjadi 36 petak. Tiap petak berukuran 4 m x 8 m, sisanya untuk jalan dan jarak antar petakan. Sebelum penanaman tanah diolah terlebih dahulu, pengolahan tanah dilakukan tiga minggu sebelum bibit ditanam di lapang. Pengolahan tanah dilakukan sebanyak dua tahap. Setelah tanaman berumur 7 minggu setelah tanam (MST) maka bibit tersebut siap dipindahkan ke lapang. Bibit ditanam dengan jarak tanam 2 m x 2 m pada petak yang telah ditentukan pada masing-masing ulangan dengan satu bibit per lubang tanam. Pemupukan dilakukan berdasarkan perlakuan yang diujieobakan, pupuk K20 diberikan sekaligus saat tanam sedangkan N diberikan bertahap yaitu 2/3 dosis pada saat tanam di lapangan dan 113 dosis sebulan kemudian. Kegiatankegiatan dalam pemeliharaan tanaman meliputi penyulaman, penyiangan dan pengendalian hama dan penyakit tanaman.
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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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