Judul: Pengaruh Pupuk Mikro-Biostimulant Cair dan Bahan Organik terhadap Pertumbuhan dan Serapan N, P dan K Tanaman Caisim (Brassica juncea) pada Latosol (Oxic Dystrudept), Darmaga
Abstrak: Latosol fertilty is generally low because of its organic content and lack of nutrient availability. One way to overcome its fertility was to used some fertilizer, both organic and inorganic fertilizers. Fertilizer can be applied to the soil and plants. Fertilizers by plants typically use a liquid fertilizer that is expected can overcome the deficiencies of nutrients and effectiveness of absorption. Sufficient nutrients and balance of plant are necessary. Plants can growth well when they have good support from condition and nature of soil so plants can used nutrients to its full potential. Nutrients needed by plants consist of macro elements (C, H, O, N, P, K, Ca, Mg, and S) and micro elements (Fe, Mn, Mo, B, Cu, Zn, and Cl). If all of the elements were not met, plants would growth abnormal. Micro nutrients needed in smaller amounts than fertilizer macro, but its presence is very important, for example in plant metabolic reactions, especially associated with the activity of the enzyme. Maximum growth and production can be ensured by maintain the amount of macro and micro nutrient status. One way to overcome micro-nutrient deficiencies are generally carried out through the leaves. The purpose of this research was to study the effect of Fertilizer Micro-Liquid Biostimulant and organic matter on growth and N, P and K uptake by Chinese Mustard (Brassica juncea) var. Tosakan in Latosol, Darmaga. The research arranged according to Completely Randomized trial using factorial design of two-factor repeated 5 times. The first factor was the Micro-Biostimulant Liquid Fertilizer (MBC) consisting of 4 levels, ie, MBC-0%, MBC-50%, MBC-100% and MBC-150%. The second factor was an organic matter consist of three doses, ie, without organic matter, 2.5 tons/ha of organic matter and 5.0 tons / ha of organic matter. The results showed that MBC treatment equivalent to 100% recommended doses provide the highest results for fresh weight and plant uptake of N, P and K. Aplication of MBC 100% significantly increased the fresh weight by 21% and nutrient uptake of N 27%, P 29% and K 20% compared with MBC 0%. The application of organic matter (cow manure) 5 ton/ha gave the highest results of the fresh weight and nutrient uptake of N, P and K. The treatment was significantly increased the fresh weight by 24% and nutrient uptake of N 23%, P 24% and K 25% compared with without organic matter. There was no interaction between MBC treatment and application of organic matter for all parameters.
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Judul: Uji efektivitas pupuk organik cair terhadap produksi dan serapan hara tanaman Caisim (Brassica juncea) varietas Tosakan pada Latosol Darmaga
Abstrak: Latosol fertility is generally low because of its low organic matter content and nutrient availability. One of many ways to overcome the low fertility of Latosol is adding fertilizers, either organic or inorganic fertilizers. Fertilization can be applied through the soil or plants. Fertilizer that applied through the plants is usually provided by liquid fertilizer which sprayed on the plant leaf. This experiment was conducted from January to May 2010 in greenhouse located in Cikabayan, IPB. Soil and plant analysis were conducted at the Laboratory of Chemistry and Soil Fertility, Department of Soil Science and Land Resources, Faculty of Agriculture, Bogor Agricultural University. The purpose of to test the effectiveness of liquid organic fertilizer to the growth of caisim plants (Brassica juncea), Tosakan variety in Latosol Darmaga. The experiment design using Completely Randomized Design (CRD) comprised of seven treatments with five replications. Treatments consisted of no fertilizer added (Control), 100% chemical or standard fertilizer (PS), 75% liquid organic fertilizer (PO) + 50% PS, 75% PO + 75% PS, 100% PO + 50% PS, 100% PO + 75% PS, and 125% PO + 50% PS. The results showed that the effect of chemical (standard) fertilizer or a combination of chemical fertilizer and liquid organic fertilizer on the growth parameters (weight of fresh leaves and weight of dry leaves), leaf nutrient content (N and K), P nutrient content of root and nutrient uptake (N, P, and K) , and RAE value were significantly higher than control. Generally, liquid organic fertilizer showed the effectiveness if it was combined with chemical fertilizer of its lower rate (75%). It was the most effective fertilizer combination than other treatments.
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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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