Judul: Pengaruh Pupuk Organik dan NPK terhadap Serapan Hara dan Hasil Jagung Manis di Latosol Dramaga.
Abstrak: Sweet corn cultivation carried out by farmers around Bogor commonly only use inorganic fertilizers without incorporating the corn stalks into the soil and used as animal feed. Cultivation as above continously can lead to decreased of soil organic matter. This trial was conducted to test the effectiveness of organic manure and NPK fertilizer on the growth and yield of sweet corn. This trial was conducted in IPB experimental station at Cikabayan from May 2014 until November 2014. Factorial randomized block design was used in this trial with two factors. The first factor was the organic manure with 3 levels of dosages, namely: O0 = 0 t/ha, O1 = 2.5 t/ha (6:25 kg/plot) and O2 = 5 t/ha (12.5 kg/plot). The second factor was the NPK fertilizer with 4 levels namely: P0 = 0%, P1 = 50%, P2 = 75% and P3 = 100% standard dosage of NPK. Standard dosage of NPK fertilizer consisting of urea 250 kg/ha, SP-36 150 kg/ha and KCl 200 kg/ha. Variables measured were plant height, weight of cob and dry biomass, nutrient uptake and Relative Agronomic Effectiveness (RAE). The results showed that treatment of NPK fertilizer increased crop height while main effect of organic manure did not significantly incrace. Treatment with a combination of organic manure and NPK fertilizer increased the weight of cob and dry biomass. NPK fertilizers influenced the uptake of N, K and dry biomass, but not significanly on the uptake of P. Acording to relative agronomic effectiveness showed that the application of organic manure could reduce the NPK fertilizer.
Keyword: Nutrient uptake, yield, organic manure

Judul: Efektivitas Pupuk Organik Granul terhadap Pertumbuhan, Produksi dan Kadar Hara NPK Daun Jagung Manis pada Latosol Dramaga
Abstrak: Latosol fertility is generally low due to low nutrient availability and organic matter content, so addition of anorganic fertilizer only will not provide optimal production of plants. Therefore, additional of organic fertilizer must be done. The objective of this research is to study the effectiveness of granulated organic fertilizer which was combined with standard fertilizer on the growth, production, and NPK contents of sweat corn leaves in Latosol Dramaga. The field experiment was conducted in the University Farm IPB, from Februari to August 2012. The nutrient content was analyzed in the Laboratory of Soil chemistry and Fertility, Faculty of Agriculture, IPB. The design of research was completely randomized block design with single factor, that was combination of anorganic fertilizer (standard) with organic fertilizer, which consisted of 7 treatments: control, standard, 50% standard + 100% organic (0,5S+1PO), 50% standard + 150% organic (0,5S+1,5PO), 75% standard + 100% organic (0,75S+1PO), 75% standard + 150% organic (0,75S+1,5PO), and 100% standard + 100% organic (1S+1PO). The result of the research showed that the granulated organic fertilizer increased of growth, production of corn, and nutrient content of corn leaves effectively. The two treatment combinations (1S+1PO) and (0,75S+1PO) showed the best performance, which was indicated by the weight of corn with huskcover and value of RAE i.e. 15,58 t/ha and 162,07% (1S+1PO), and 13,97 t/ha and 128% (0,75S+1PO), respectively. The effect of both treatment combinations above were higher than standard treatment (12,58 t/ha and 100%).
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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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