Judul: Efektivitas Pupuk Organik terhadap Pertumbuhan, Produksi, dan Kadar Hara NPK Daun Jagung Manis di Latosol Darmaga
Abstrak: Sweet corn is seed plant which is commonly planted in Indonesia because of it's sweet taste and contain high carbohydrate. One of the problems in cultivation of sweet corn is low soil fertility, due to the lack of soil nutrient availability and organic matter. To solve that problem can be done by applying organic and anorganic fertilizers. Organic fertilizer is able to increase chemical fertilizer efficiency through improving of physical, chemical and biological of soil. So it is expected to increase the production of plant significantly. The objective of this research is to study the effectiveness of organic fertilizers that was combined with inorganic fertilizer on the growth, production, and N, P, K content of sweet corn leaf in Latosol Darmaga. The field experiment was conducted at the University Farm IPB and plant analisis in the laboratory of soil chemistry and fertility, Department of soil science and Land Resources Faculty of Agriculture IPB. The materials used were organic fertilizers, inorganic fertilizers, seeds of sweet corn (Seleksi Darmaga III), furadan, and agricultural lime. The design of the experiment was a randomized complete block design (RCBD) with a single treatment consisted of 7 treatments which was repeated 3 times each, so there were 21 experimental units. Those seven treatments were: (1) control, (2) Standard (S), (3) 0.5 S + 1.5 PO, (4) 0.5 S + 1 PO, (5) 0.75 S + 1 PO, (6) 1 S + 1 PO and (7) 0.75 S + 1.5 PO. The parameters measured were plant height, production (corn cobs weight including the cornhusk and stover weight), and N-, P-, K-content of corn leaf. The results of this research showed that additional of organic fertilizer with inorganic fertilizer was effective in improving the growth, production, and N, P, K content of sweet corn leaf. The production for treatment 1 S + 1 PO was 14.31 t/ha greater (2.37 t/ha) than standard treatment, and 11.81 t/ha greater than control treatment (no fertilizer application).
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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: 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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