Judul: Response of Fertilizing B and NPK to the growth of sweet  corn plants (Zea mays L. Saccharata) on Dramaga Inceptisols
Abstrak: Jagung manis (Zea mays L. Saccharata) adalah salah satu tanaman pangan dan bahan baku industri di Indonesia dan dunia. Peningkatan produktivitas jagung manis dapat dilakukan melalui optimasi pemupukan nitrogen (N), fosfor (P), kalium (K) dan boron (B) merupakan hara makro dan mikro esensial yang dibutuhkan tanaman jagung untuk dapat tumbuh dan berkembang serta berproduksi secara optimal. Penelitian ini bertujuan untuk mengetahui kandungan B dan NPK dalam tanah dan tanaman serta pertumbuhan dan perkembangan jagung manis sebagai respon dari kombinasi pemberian pupuk mikro B dan NPK pada Inceptisol Dramaga. Penelitian menggunakan Rancangan Acak Kelompok (RAK) dengan delapan perlakuan (B0S0, B0S1, B1S1, B2S1, B3S1, B1S2, B2S2, B3S2) yang terdiri dari empat taraf B (0, 9, 18, 27 kg/ha) dan tiga taraf NPK (0%, 75% dan 100% std). Perlakuan diulang kedalam empat kelompok menghasilkan 32 petak percobaan. Kombinasi pemberian pupuk B dan NPK signifikan meningkatkan B tersedia dalam tanah. Selain itu, pemberian pupuk B dan NPK meningkatka panjang daun, dan kadar B dalam tanaman serta mempercepat umur berbunga betina (silking). Pemberian 9-18 kg/ha B dan 75% NPK memiliki pengaruh positif yang relatif konsisten pada semua parameter agronomis yang diteliti. Perlu adanya penelitian lanjutan untuk melihat pengaruh pemberian pupuk B dan NPK terhadap produksi jagung manis pada tanah dengan kesuburan yang berbeda-beda, serta kombinasi waktu dan cara pemupukan B., Sweet corn (Zea mays L. Saccharata) is one of the staple crops and raw materials for the industry in Indonesia and globally. Increasing the productivity of sweet corn can be achieved through the optimization of nitrogen (N), phosphorus (P), potassium (K), and boron (B) fertilization, which are essential macro and micronutrients required for the optimal growth, development, and production of corn plants. This research aims to determine the content of B and NPK in soil and plants, as well as the growth and development of sweet corn in response to the combination of B and NPK micro-fertilizer application in Inceptisol Dramaga. The study utilized a Randomized Complete Block Design (RCBD) with eight treatments (B0S0, B0S1, B1S1, B2S1, B3S1, B1S2, B2S2, B3S2) consisting of four levels of B (0, 9, 18, 27 kg/ha) and three levels of NPK (0%, 75%, and 100% standard). The treatments were replicated into four blocks, resulting in 32 experimental plots. The combination of B and NPK fertilizer application significantly increased the available B in the soil. Additionally, B and NPK fertilization enhanced leaf length, and B content in the plants, as well as accelerate the female flowering age (silking). The application of 9-18 kg/ha B and 75% NPK showed a relatively consistent positive influence on all agronomic parameters studied. Further research is needed to examine the impact of B and NPK fertilizer application on sweet corn production in soils with varying fertility and explore the timing and methods of B fertilization
Keyword: Availability, boron, NPK, soil parameters, sweet corn

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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