Judul: The Effect of Inorganic Boric Fertilizer on the Growth and Production of Sweet Corn in Dramaga Latosol
Abstrak: Pemupukan unsur mikro diperlukan terutama pada tanah-tanah pertanian yang intensif, salah satunya boron. Boron (B) merupakan unsur hara mikro esensial yang berperan penting dalam peningkatan produksi tanaman. Penelitian ini bertujuan menguji efektivitas pupuk an-organik borat terhadap pertumbuhan dan produksi jagung manis (Zea mays saccharata Sturt). Percobaan ini menggunakan Rancangan Acak Kelompok satu faktor, yaitu delapan perlakuan kombinasi pupuk borat (B) dan pupuk NPK Standar (NPK) meliputi: (1) Kontrol (tanpa B dan tanpa NPK); (2) Standar (tanpa B + 1 NPK); (3) ½ B + 3/4 NPK; (4) 1 B + 3/4 NPK; dan (5) 1½ B + 3/4 NPK; (6) ½ B + 1 NPK; (7) 1 B + 1 NPK; (5) 1½ B + 1 NPK. Setiap perlakuan diulang 4 kali sehingga diperoleh 32 satuan percobaan. Satu dosis pupuk borat (1 B) setara dengan 12 kg/ha pupuk an-organik borat (46% B2O3). Satu dosis NPK standar adalah 300 Urea/ha, 200 SP36/ha, dan 150 KCl/ha. Hasil penelitian menunjukkan bahwa pupuk borat nyata meningkatkan, bobot segar brangkasan, dan produksi tongkol jagung manis, serta mengefisienkan pemupukan NPK. Pemupukan borat nyata meningkatkan produksi tongkol dibanding Kontrol, namun tidak berbeda nyata dibanding Standar. Rekomendasi pemupukan jagung manis menggunakan pupuk an-organik borat adalah 12 sampai 18 kg/ha.
Keyword: Boron, fertilization efficiency, RAE, trace elements, Zea mays

Judul: The Effect of Combination B and NPK Fertilizer on the Growth of Swet Corn and Some Nutrients in Darmaga Inceptisols
Abstrak: Tanah-tanah di daerah tropik memiliki kadar B total dan tersedia yang rendah. Intensifikasi produksi dalam jangka panjang berpotensi menyebabkan defisiensi B dan penurunan produktifitas jagung manis. Penelitian ini bertujuan untuk mengetahui kadar B tersedia tanah dan kadar B daun, N-total, P-total dan tersedia serta K-dd dalam tanah. Rancangan percobaan menggunakan Rancangan Fraksional Acak Kelompok non faktorial dengan delapan perlakuan yang terdiri dari kontrol (B0S0), standar (B0S1), B1S1, B2S1, B3S1, B1S2, B2S2, dan B3S2 dengan empat ulangan sehingga terdapat 32 satuan percobaan. Pupuk kandang dan kapur sebagai pupuk dasar diberikan ke seluruh petak satu minggu sebelum tanam. Hasil penelitian menunjukkan bahwa kombinasi pupuk B dan NPK tidak signifikan dalam meningkatkan kandungan P-total dan tersedia, K-dd dalam tanah, kadar B daun, dan pertumbuhan jagung manis. Namun signifikan meningkatkan kadar B tersedia tanah, N-total, dan mempercepat menculnya bunga jantan (tasseling). Perlakuan B1S1 dengan dosis pupuk B = 9 kg/ha dan NPK = 300 kg/ha optimal dalam menunjang pertumbuhan dan mempercepat fase pembungaan jagung manis., Soils in tropical climates have low total and available B content. Intencification of production on the long term, potentially cause B deficiency and decreasing the productivity of sweet corn. This study aims to determine the content of available B in soil and B in leafes, total-N, total and available P, and exchangeable Potassium in the soil. The experimental design used non-factorial Randomized Fractional Design with eight treatments consisting of control (B0S0), standard (B0S1), B1S1, B1S1, B2S1, B3S1, B1S2, B2S2, and B3S2 with four replications so there were 32 experimental units. Manure and lime as basic fertilizers were applied to all plots one week before planting. The results showed that the combination of B and NPK fertilizers were not significant in increasing the total and available P content, exchangeable Potassium in the soil, content of B in leafes, and the growth of sweet corn. However, it’s significant in increasing the available B content in the soil, total-N, and accelerate the appearance of male flowers (tassel). B1S1 treatment with a dose of fertilizer B = 9 kg/ha and NPK= 300g/ha is optimal in supporting growth and accelerating the flowering phase of sweet corn.
Keyword: Availability, boron, deficiency, soil parameters, sweet corn

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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