Judul: Kesuburan Tanah pada Hutan Organik Megamendung Bogor
Abstrak: Evaluasi kesuburan tanah merupakan cara untuk mendiagnosa keharaan di dalam tanah. Evaluasi kesuburan tanah juga penting untuk mengetahui status kesuburan tanah dalam suatu lahan. Penelitian ini bertujuan menentukan status kesuburan tanah pada Hutan Organik Megamendung Bogor. Penelitian ini dilakukan melalui 2 tahap yaitu pengambilan sampel tanah di lapang dan analisis sampel tanah di laboratorium. Setelah dilakukan analisis di laboratorium, maka selanjutnya dilakukan penilaian sifat-sifat tanah dan penilaian status kesuburan tanah. Hasil analisis laboratorium pada kerapatan tajuk rendah, sedang, tinggi menunjukkan nilai pH tanah masam (pH 5.21, pH 5.24, dan pH 5.35), C-Organik tergolong sedang (2.17%, 2.75%, dan 2.79%), kandungan P total tergolong sedang sampai sangat tinggi (37.23 mg/100g, 60.47 mg/100g, dan 60,86 mg/100g), kandungan K total tergolong sangat rendah (4.61 mg/100g, 4.43 mg/100g, 3.71 mg/100g), KTK tergolong rendah (15.50 me/100g, 14.41 me/100g, 16.17 me/100g), dan kejenuhan basa sangat rendah (5.87%, 11.86%, 17.36%). Berdasarkan hasil analisis, status kesuburan tanah pada lokasi penelitian hutan organik tergolong rendah.
Keyword: hutan organik, kerapatan tajuk, kesuburan tanah, penilaian sifat tanah, status kesuburan tanah

Judul: Kesuburan Tanah pada Hutan Wakaf Kampung Muara, Kecamatan Pamijahan, Kabupaten Bogor, Jawa Barat
Abstrak: Pengetahuan tentang karakteristik dan kualitas tanah perlu diketahui untuk menilai dan memantau kesuburan tanah. Penelitian ini bertujuan untuk menentukan status kesuburan tanah Hutan Wakaf Kampung Muara Bogor. Penelitian dilakukan dengan mengambil sampel tanah terusik di lapangan pada tiga tingkat kerapatan tajuk dan dilanjutkan dengan analisis di laboratorium. Setelah dilakukan analisis, selanjutnya dilakukan penilaian sifat kimia tanah dan penilaian status kesuburan tanah. Hasil analisis laboratorium pada kerapatan tajuk rendah, sedang dan tinggi menunjukan pH tanah masam (pH 5,23; pH 4,58; dan pH 4,44), C-Organik tergolong tinggi (3,56%; 5,21% dan 7,98%), kandungan P potensial tinggi (63,45 mg/100g, 20,70 mg/100g, dan 54,47 mg/100g) kandungan K potensial rendah (26,61 mg/100g, 7,11 mg/100g dan 13,37 mg/100g), KTK tergolong tinggi (36,67 cmol/kg, 26,34 cmol/kg dan 28,22 cmol/kg) dan kejenuhan basa sangat rendah (24,57%, 6,30% dan 4,57%). Berdasarkan hasil analisis, status kesuburan tanah pada lokasi penelitian tergolong rendah., The knowledge of quality and characteristics of soil is a vital information for soil assessment and monitoring. This research is aiming to determine the soil fertility in Bogor Waqf Forest Kampung Muara. The research was conducted by collecting disturbed soil samples in three levels of canopy, and followed with laboratory analysis. After the samples are analyzed, an assessment of soil’s chemical properties and an assessment of soil fertility status were enacted. Results of Laboratory analysis on low, medium and high canopy density showed acidic soil pH values (pH 5,23; pH 4,58; and pH 4,44), C-Organic classified as high (3,56%, 5,21% and 7,98%), potential P content classified as high (63,45 mg/100g, 20,70 mg/100g and 54,47 mg/100g), potential K content classified as low (26,61 mg/100g, 7,11 mg/100g and 13,37 mg/100, CEC was high (36,67 cmol/kg, 26,34 cmol/kg and 28,22 cmol/kg), and base saturation was very low (24,57%, 6,30% and 4,57%). Based on the results of the analysis, soil fertility status of Bogor Waqf Forest was relatively low.
Keyword: hutan wakaf, kerapatan tajuk, kesuburan tanah, sifat tanah, status kesuburan tanah

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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