Judul: Kajian agronomis tanaman buah dan sayuran pada struktur agroforestri pekarangan di Wilayah Bogor, Puncak dan Cianjur (Studi Kasus di DAS Ciliwung dan DAS Cianjur)
Abstrak: Luas lahan pertanian makin berkurang, dilain pihak kebutuhan pangan makin meningkat akibat bertambahnya jumlah penduduk. Lahan pekarangan merupakan salah satu alternatif dalam sumbangsih ketahanan pangan di masyarakat. Pemanfaatan lahan pekarangan dengan budidaya berbagai jenis tanaman, termasuk budidaya tanaman buah dan sayuran merupakan bentuk praktek agroforestri. Keragaman tersebut dipengaruhi oleh kondisi agroklimat di daerah aliran sungai (DAS). Pekarangan mempunyai potensi sebagai lumbung pangan cukup besar, dengan lahan pekarangan yang cukup luas. Di kabupaten Bogor sebesar 38.404 ha dan di Kabupaten Cianjur sebesar 41.273 ha. Penelitian yang terkait tanaman tak terkecuali tanaman buah dan sayuran, pada umumnya dilakukan di lahan yang khusus untuk budidaya tanaman tersebut. Mengingat potensi dan luas lahan pekarangan cukup besar yang selama ini terabaikan, maka perlu dilakukan penelitian di lahan pekarangan.
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Judul: Struktur, Fungsi dan Dinamika Keanekaragaman Hayati Pertanian Pada Pekarangan di Hulu DAS Kalibekasi, Kabupaten Bogor
Abstrak: Indonesian typical home garden, “pekarangan”, has several ecological potentials of agrobiodiversity. Nevertheless, pekarangan management in Indonesia is facing several problems, such as decreasing plot size, decreasing plant species for production function, but increasing number of ornamental plants for aesthetic function. The objectives of this research are to propose recommendations on agrobiodiversity conservation in pekarangan by analyze the structure, function and spatial dynamic of pekarangan agrobiodiversity in the upper stream of Kalibekasi watershed. This research was conducted in Cimandala, Landeuh and Leuwijambe hamlets which represented the upper part, the middle part and the lower part of the upper stream of Kalibekasi Watershed, respectively, and Sentul City as the urbanized area for comparison. There are 48 samples of pekarangan were observed and analyzed. It was found that pekarangan in the rural area of the upper stream of Kalibekasi watershed have larger space in front yard and one of side yard, but smaller in back yard with multilayer plants. The main function of pekarangan in rural area is a media for production, but in urban area are for micro-climatic amelioration and aesthetic function. The numbers of Margalef index and Shannon-Wiener index show that the upper part has the highest plant diversity. While, the values of Sørensen coefficient indicate that the middle part is the transition place of species similarity of the upper and the lower part. The proposed recommendation is to hold and maintain pekarangan with high diversity of plants and livestocks, which householders get benefit from the product.
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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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