Judul: Pengaruh Taraf Pupuk Organik Yang Diperkaya Terhadap Pertumbuhan, Produksi, Kandungan Hara N, P, K Tanaman Jagung Manis (Zea Mays Saccharata Sturt), Dan Nilai Kritisnya Pada Latosol Darmaga
Abstrak: Dampak negatif yang disebabkan oleh penggunaan pupuk anorganik menclorong petani untuk kcmbali ke sistem pertanian organik (organic farming system). Namun, karena proses clekomposisi pupuk organik yang lambat dan jumlahnya yang terbatas menyebabkan hara yang dapat diserap oleh tanaman untuk pcrtumbuhannya juga menjacli seclikit. Oleh karena itu, cliperlukan kombinasi antara pupuk organik clengan pupuk anorganik. Tujuan penelitian ini aclalah untuk menguji efektivitas taraf pupuk organik yang cliperkaya terhaclap pertumbuhan, procluksi, kanclungan hara N, P, K tanaman clan nilai kritisnya pacla tanaman jagung manis pacla Latasol Oarmaga. Penelitian ini clilakukan di Kebun Percobaan Cikabayan, Bogor. Analisis tanamandilakukan di Laboratorium Kimia dan Kesuburan Tanah, Departemen Tanah, Fakultas Pcrtanian, Institut Pertanian Bogor. Penelitian berlangsung mulai bulan Maret sampai bulan September 2003.
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Judul: Pengaruh Pemberian Pupuk Organik pada Produksi dan Serapan Hara Jagung Manis (Zea mays) di Latosol, Darmaga
Abstrak: There are two form of organic fertilizers, solid and liquid. Solid organic fertilizer is usually applied to the soil. The advantage in application of organic fertilizers able to adsorb nutrients that easily lost and supply availability of nutrients and therefore can increase efficiency of fertilizer. The purpose of this study was to study the effect of organic fertilizer application on Latosol, Darmaga to production and nutrient uptake of corn as plant indicator. The experiment was conducted in the greenhouse by using completely randomized design consisting of seven treatments and each treatment was repeated four times so that there were 28 pot experiments. Seven treatments were consisted of control, standard, 75% PO + 50% S, 75% PO + 75% S; 100% PO + 50% S; 100% PO + 75% S, and 125% PO + 50% S. The parameters measured were plant height, weight of shoot, root weight, ear weight with and without cornhusk, uptake of N, P, and K nutrients in shoot and plant roots and the Corganic content, N-total, and CEC (cation exchange capacity) soil after the experiment. The result of experiment showed that the application of organic and anorganic (standard) fertilizer on plant height and weight of shoot was not significantly different than standard fertilizer (100% S). The weight of plant roots and nutrient uptake of N, P, and K of the shoot and plant roots in the treatment of 100% PO + 75% S was significantly higher than other treatments. Treatment combination of organic and anorganic (standard) fertilizer at the lower doses of standard recommendation significantly increased ear weight with and without cornhusk. Dosage recommendations based on the RAE value are the treatment of 100%PO + 50%S (158,66%) and 75%PO + 50%S (142,52%). The analysis of soil after the experiment showed that the use of organic fertilizer combined with anorganic fertilizer (standard) produced levels of C-organic, N-total, and the CEC soils tend to be higher than the standard (100% S) and control treatments. The use of organic fertilizer combined with anorganic (standard) fertilizer at lower doses (50% S and 75% S) increased effectiveness of fertilizer to increase the growth and production of corn.
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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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