Judul: Pengaruh pupuk organik pada produksi dan serapan hara tanaman Caisim (Brassica juncea) varietas Tosakan pada Latosol Darmaga
Abstrak: Indonesian lands are dominated by acid soils and generally have low soil fertility due to tropical high rainfall that resulted in highly leaching and weathering. One of ways to improve soil fertility is by using fertilizer. Application of organic fertilizer are able to increase soil properties such as increasing soil nutrients, organic carbon and soil CEC which will provide soil nutrients and increase the efficiency of fertilizer. This research aims to evaluate the effect of organic fertilizer to the yield, nutrient content and uptake of the leaf caisim (Brassica juncea) on Latosol Darmaga and also to calculate the farming R/C (Revenue Cost Ratio) analysis. The Research was conducted in the field of University Farm Cikabayan, Bogor. Fertilizer that used in this research were organic fertilizer (OF) and standard (S). The form of organic fertilizer were granule and recommendation of the dose was 2 ton/ha. Then, standard was a conventional recommendation used for Caisim, there were 200 kg urea/ha, 300 kg SP-36/ha and 100 kg KCl/ha. Plant analysis was conducted in Chemical and Soil Fertility Laboratory, Faculty of Agriculture, IPB. This research design was Randomize Complete Block Design (RCBD) with 7 doses of treatment and 4 replication, so that there were 28 experimental units. The treatments were : Control, Standard (S), 75% OF + 50% S, 75% OF + 75% S, 100% OF + 50% S, 100% OF +75% S, and 125% OF + 50% S. The result showed that combination of organic fertilizer with standard fertilizer, and standard fertilizer only significantly have higher yield compared with control in parameters such as plant weight, leaf nutrient content (P) and leaf uptake (N, P and K). Additional of organic fertilizer improved effectivity of fertilizer to yield because organic fertilizer with additional of standard fertilizer in lower dose (50% and 75%) were able to produce higher number of plant/plot than standard fertilizer treatment only. Economic farming analysis indicated that combination organic and standard fertilizer were profitable economically. The highest value for parameters such as production, nutrient content, nutrient uptake and R/C ratio occurred in 75%PO + 75%S and 100%PO and 75%S.
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Judul: Pengaruh pupuk organik cair pada produksi dan serapan hara tanaman Caisim (Brassica juncea) varietas Tosakan pada Latosol Darmaga
Abstrak: Indonesia is situated in tropical region with high rainfall and temperature. These high rainfall and temperature affect the soil fertility through intensive weathering and leaching process. Leaching process could lead the decrease of basic cations and other important elements for plant. Further it makes soils in Indonesia acid and infertile. One of ways to improve the soil fertility is the application of fertilizer. The fertilizers could be applied through leaf and soil. Leaf fertilizer is applied by using foliar feeding method directly to the leaf so the essential nutrient absorbed by itself through the leaf. Leaf fertilizer is in liquid form, enrich by macro and micro nutrients. The objectives of this research were to determine the effect of liquid organic fertilizer to the yield, nutrient content and nutrient uptake of nitrogen (N), phosphorus (P) and potassium (K) of the caisim (Brassica juncea). This research also aims to determine the effectiveness of fertilizer that is measured by Relative Agronomic Effectiveness (RAE). The experiment was conducted in the greenhouse of University Farm in Cikabayan, Bogor. Analysis concerning nutrient content and plant uptake of N, P and K were carried out in Chemical and Soil Fertility Laboratory, Agricultural Faculty, IPB. Greenhouse expriment was set up in Completely Randomize Design (CRD) with seven treatments and four replications The treatments were as follows: control, standard (S), 0,75PO+0,5S, 0,75PO+0,75S, 1,0PO+0,5S, 1,0PO+0,75S, dan 1,25PO+0,5S. Standard was the treatment using Urea, SP-36 and KCl fertilizers with the rates 200kg/ha, 300kg/ha and 100 kg/ha respectively. PO in the treatments label referred to leaf organic fertilizer while S referred to standard. As for liquid organic fertilizer, the recommended rate was 5 L/ha. The result showed the addition liquid organic fertilizer (PO) and standard fertilizer in lower dose (0,5S and 0,75S) effective in improving the yield of caisim. Nutrient uptake (N and K) in these treatments (0,75PO+0,75S and 1,0PO+0.75S) tended to have higher value than the standard. Meanwhile nutrient uptake (P) in combine dose of PO and S have higher value than standard. In RAE value, the combine dose gave a higher tendency than the standard, whereas this combine dose of treatment (1,0PO+0,5S) resulted in higher value than those of others treatments. Based of the results and considering the RAE values, it suggested that treatment of 1,0PO+0,5S was recommended as fertilizer dose that should be applicated.
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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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