Judul: Emisi gas CH4 dan serapan karbon dari aplikasi pupuk anorganik, organik dan tanaman sela pada budidaya jarak pagar
Abstrak: Production of Jatropha as a biofuel can be increased by fertilization. Subtitution chemical fertilizer into organic fertilizer have to consider the methane (CH4) emissions from soil that fertilizer applied. In this study the rate of methane (CH4) emission from jatropha cake compost (-0.99 CH4/m2/hour) and peanuts intercrops (- 0.62 CH4/m2/hour) is lower than urea fertilizer (- 0.04 CH4/m2/hour). Carbon sequestration is a reference to see the potential of the plant to reduce the CO2 in the atmosphere. Application of urea fertlizer showed carbon uptake (13.62 tonnes C/ha/year) higher than between fertilizer application (12.83 ton C/ha/year) and jatropha cake compost (11.09 tonnes C/ha/year). The productivity of jatropha from the jatropha cake compost (152 kg/ha/year) and intercrops (147.1 kg/ha/year) application was higher than urea fertilizer (147 kg/ha /year).
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Judul: Aplikasi Kompos Bungkil Jarak Pagar untuk Mereduksi Emisi Gas Rumah Kaca Karbondioksida (CO2), Metana (CH4) dan Dinitro-Oksida (N2O) dari Perkebunan Jarak Pagar
Abstrak: Jatropha curcas cake compost application in agricultural practiced can increase soil organic carbon and improve amonification, nitrification and nitrogen fixation which good for plant. On the other hand, compost had potentially increase greenhouse gas (GHG) emission especially CO2, CH4 and N2O. This research was conducted to measure the GHG of this compost application and have been done in two steps. Firstly, clear the diurnal change in the GHG emission to determine the time of maximum GHG emitted to the air. It showed that the average concentration of CO2 and CH4 was higher during nighttime while N2O was higher during daytime. The maximum concentration of CO2, CH4 and N2O appears at 06:00 p.m. (354 ppm), 05:00 a.m. (5.4 ppm) and 04:00 p.m. (5.5 ppm). Secondly, identification of CO2, CH4 and N2O emission from compost application and compared to an-organic fertilizer (urea and slow release urea). The result showed that concentration of CH4 from Jatropha curcas cake compost was lower than urea at 3, 5 and 7 day after fertilization while N 2O from compost was higher at 3 and 14 day after fertilization. Urea application enhances CH4 emission by increasing metanogen activity. Meanwhile, addition of organic matter into soil caused oxygen deficiency and increase nitrate denitrification to N2O. Compared to slow release urea, CH4 concentration from compost was higher at 3, 5 and 14 day after fertilization. N2O from compost was lower at 5 and 14 day after fertilization. Calculation of total CH4 and N2O during 14 day showed that CH4 from compost was lower (621 mgC/m2) than urea (630 mgC/m2) and slow released urea (638 mgC/m2) while N2O from compost was highest (455 mgN/m2).
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Judul: Grup dan Homomorfisma Grup pada Rubik Revenge
Abstrak: Rubik cube is a kind of puzzle game. A player must arrange rubik sides, which have been disordered, back to the position where every side has the same colour. This paper does not focus on the settlement solution, but instead on proving the existence of a group homomorphism between rubik movement group and S96 symmetric permutation group in rubik revenge. Firstly, it has been proved that rubik movement set is a group. Then, it also has been proved that the M set, which contains numeric labels of 1 until 96 in cubinos sides, is S96 symmetric permutation group.
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