Judul: Pengaruh serasah daun jati, urea dan biostimulan terhadap rumput setaria gajah dan rumput agustin di bawah tanaman jati
Abstrak: The aim of the experiment was to study the effect of giving teak leaves compost, urea and biostimulan on the growth and production of setaria and Agustin grass planted under teak wood. This experiment using Randomized Block Design with 8 treatments and 3 replications. The data were analyzed with Analyze of Variance (ANOVA) and the significant differences were further tested by Duncan Multiple Range Test. Variables measured were the increase of stolon length, stolon number, veflikal height, tiller numbers, dry catter production and infected root percentage. The result showed that treatments significantly (P<0.01) affected the percentage of infected root of the first harvest of Agustin grass as well as setaria (P<0.05). But the were no significant effect of the treatment were found 0x1 the stolon length gain, stolon number gain, vertikal height gain, tiller numbers gain, dry matter production, and infected root percentage in the second harvest.
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Judul: Pengaruh pemberian pupuk litter ayam dan nitrogen terhadap pertumbuhan dan produksi bahan kering rumput setaria gajah
Abstrak: Suatu penelitian telah dilakukan di Kebun Percobaan Institut Pertanian Bogor, Tajur Bogor. Penelitian dimulai tanggal 12 Desember 1933 dan selesai tanggal 24 Mei 1984. Tujuan penelitian adalah untuk mengetahui pengaruh pomberian pupuk litter ayam dan nitrogen terhadap pertum- buhan dan produksi bahan kering rumput Setaria Gajah (Se- taria splendida Stapf). Pupuk litter ayam diberikan dalam tiga taraf. Taraf 0 ton/ha, 9 ton/ha dan 18 ton/ha. Pupuk nitrogen yang di- berikan dalam tiga taraf. Taraf O kg/ha, 180 kg/ha dan 360 kg/ha. Tiap kombinasi perlakuan ditanam pada unit penelitian seluas 2 x 2m. Rancangan percobaan yang digunakan adalah rancangan berblok dengan pola faktorial (3 x 3). Ilasil penelitian menunjukkan bahwa pemberian litter ayam 9 dan 18 ton/ha menghasilkan tanaman yang nyata lebih tinggi (P0.01) daripada tanpa litter ayam. Hal yang sama terjadi pula pada pemupukan urea 180 dan 360 kg/ha. Demikian pula pemberian litter ayam maupun urea menghasil- kan anakan yang nyata lebih banyak daripada tanpa pemberian litter ayam maupun urea. Namun peningkatan dosis litter ayam dari 9 ton/ha menjadi 18 ton/ha maupun poningkatan dosis urea dari 180 kN/ha menjadi 360 kg/ha tidak nyata meningkatkan pembentukan anakan. Pemberian litter ayam 9 dan 18 ton/ha menghasilkan bahan kering yang nyata lebih banyak (P0.01) daripada tanpa litter ayam. Hal yang sama terjadi pula pada pemu.. pukan urea 180 kg/ha dan 360 kg/ha. Peningkatan dosis litter ayam dari 9 ton/ha menjadi 18 ton/ha nyata mening- katkan produksi bahan kering, namun peningkatan dosis urea dari 180 kg/ha menjadi 360 kg/ha tidak nyata meningkatkan produksi bahan kering.
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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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