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.
Keyword: 

Judul: Pengaruh pupuk TSP dan sisipan kacang panjang pada tanaman rumput setaria gajah terhadap produksi dan kualitas hijauan
Abstrak: Penelitian ini bertujuan untuk mengetahui pengaruh pupuk TSP terhadap produksi dan kualitas hijauan rumput Setaria Gajah (Setaria splendida STAPF) dan jerami serta produksi polong muda kacang panjang (Vigna sinensis (Stickm) Savi Hassk) sebagai tanaman sisipan. Penelitian lapang dilakukan di kebun percobaan Institut Pertanian Bogor pada jenis tanah latosol. Penelitian ini menggunakan rancangan petak terbagi dengan empat ulangan. Petak utama merupakan perlakuan sistem pertanaman rumput Setaria monokultur dan pertanaman ganda rumput Setaria + kacang panjang. Sebagai anak petak adalah pemberian pupuk TSP dengan taraf 100, 200, 300 dan 400 kg P205/ha. Rumput Setaria ditanam dengan jarak tanam 90 cm x 60 cm dan benih kacang panjang ditanam satu baris diantara baris rumput Setaria. Pupuk urea 50 kg N/ha dan pupuk KC1 150 kg K20/ha diberikan sebagai pupuk dasar. Evaluasi produksi dan kualitas hijauan Setaria dilakukan selama 120 hari, sedangkan kacang panjang 110 hari setelah tanam. Hasil penelitian menunjukkan bahwa banyaknya anakan rumput Setaria pada periode pemotongan pertama nyata dipengaruhi oleh pemupukan TSP, sedangkan sistem pertanaman maupun interaksi antara sistem pertanaman dengan pupuk TSP belum memperlihatkan pengaruh yang nyata. Peningkatan jumlah anakan rumput Setaria baru nampak nyata apabila taraf pupuk P ditingkatkan dari 100 kg P205/ha menjadi 300 dan 400 kg P205/ha, berturut-turut sebanyak 21.03, 30.00 dan 29.05 anakan/rumpun. Pengaruh pemberian pupuk TSP menunjukkan hubungan. linier terhadap jumlah anakan rumput Setaria pada periode pemotongan pertama, dengan persamaan regresi Y 19.01 + 0.03 X (r2 = 0.83). Pada periode pemotongan kedua, interaksi antara sistem pertanaman dengan pemupukan TSP nyata berpengaruh terhadap banyaknya anakan rumput Setaria. Pemberian pupuk TSP nyata meningkatkan jumlah anakan rumput Setaria monokultur, tetapi tidak pada pertanaman ganda. Peningkatan jumlah anakan rumput Setaria monokultur baru nampak nyata apabila taraf pupuk P ditingkatkan dari 100 kg P205/ha menjadi 300 dan 400 kg P205/ha, berturut-turut sebanyak 48.42, 73.08 dan 68.33 anakan/rumpun. ...
Keyword: 

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.
Keyword: