Judul: Pengaruh Pupuk Magnesium (Mg) Terhadap Produksi dan Serapan Hara N, P, K, Ca, Mg Tanaman Kacang Hijau di Latosol Darmaga
Abstrak: Magnesium nutrient is a part of chlorophyl substance. The deficiency of Mg in the plant will decrease. The objective of this research was to determine the effect of Magnesium Fertilizer (MgO) on production and uptake of Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca) and Magnesium (Mg) of mung bean plant in Latosol Darmaga. The research design used Randomized Complete Block Design, with consist of 8 treatments were control, NPK Std, NPK Std + Kieserit, NPK Std + MgO 1, NPK Std + MgO 2, NPK Std + MgO 3, NPK Std + MgO 4, NPK Std + MgO 5 with each treatments had 3 replications. The research result showed that the addition treatment of MgO generally increased the plant height and mung bean production (total beans weight /pot and beans weight of 50 grains), especially to the treatment of NPK Std+MgO 3. Analysis of plant and soil showed that the MgO fertilizer tend to reduce content and uptake of Mg in plant leaves, but tend to increase the content and uptake of K and Ca in leaves while treatment of MgO fertilizer significantly increased exchangeable Mg (exch Mg) of soil and whereas exchangeable Ca was not different.
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Judul: Pengaruh pemupukan magnesium terhadap pertumbuhan dan produksi serta serapan beberapa hara tanaman kedelai ( Glycine max L. Merr ) pada latosol Tajur
Abstrak: Penelitian dilaksanakan di Kebun Percobaan IPB, Biotrop, Tajur. Analisis sifat kimia dan fisik tanah dilakukan di Laboratorium Jurusan Tanah dan P3S, IPB. Tujuan penelitian ini adalah untuk memperoleh informasi. dasar mengenai pengaruh unsur Mg terhadap pertumbuhan, hasil dan serapan beberapa hara tanaman kedelai (Glycine max L. Merr). Rancangan penelitian adalah Rancangan Acak Kelompok (RAK). Perlakuan tunggal pupuk Mg dalam bentuk MgSO14 (20.2 persen Mg) diberikan dalam lima takaran, masing-masing sebanyak 0, 0.25, 0.50, 0.75 dan 1.00 me/100g. Pemberian dilakukan dengan cara sebar merata di permukaan tanah. Tanaman uji yang digun: kan adalah kedelai varietas Amerikana. Hasil penelitian menunjukkan bahwa pemupukan Mg ber pengaruh nyata meningkatkan tinggi tanaman umur empat minggu dan sangat nyata umur lima dan enam minggu, sangat nyata meningkatkan berat polong isi, berat biji, berat 1 000 butir biji dan produksi biji per petak serta nyata meningkatkan jumlah polong. Produksi biji tertinggi sebanyak 1506.00 g/petak dicapai pada takaran Mg sebanyak 0.67 me/100g. Serapan Mg dan P meningkat sangat nyata dengan meningkat- nya takaran Mg, sebaliknya terhadap serapan K. Terhadap serapan Ca tidak nyata pengaruhnya. Pemupukan Mg meningkatkan Mgdd hingga takaran 1.00 me/100g dan Kdd hingga takaran 0.25 me/100g, lalu menurunkan pada takaran Mg yang lebih tinggi, sedangkan terhadap Ca dan pH H2O pengaruhnya relatif kecil….
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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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