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: 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: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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