Judul: Pengaruh Electric Furnace Slag, Silica gel dan Unsur Mikro terhadap Sifat Kimia Tanah Serta Pertumbuhan dan Produksi Tanaman Padi Sawah (Oryza sativa L.) pada Tanah Gambut dari Kumpeh, Jambi
Abstrak: The staple food of Indonesian is rice, concequently paddy is the most important crop in agriculture. Peat soil is one of marginal land which potential to create the availability of land for paddy in Indonesia. Generally, peat soil in Indonesia has low fertility and availability of silicon (Si). Silicon is beneficial element for paddy rice. Recently, general material used as sources of Si in some countries is steel slag of which consist calcium silicate. One kind of steel slag produced in Indonesia is electric furnace slag. However, according to regulation of government (PP No. 18, 1999 and No. 85, 1999), steel slag is categoried at hazardous waste. The objectives of this research were to determine the effect of EF slag, silica gel, and micro elements on chemical properties of soil, growth and yield of paddy rice on peat soil and to evaluate content of heavy metal in rice for worthiness of rice consumption. This research used peat soil from Kumpeh Regency, Jambi. The research consisted of two experiments, they were incubation experiment in laboratory and pot experiment in greenhouse. The dosage applied for treatment of EF slag and silica gel were 0%, 2%, 4%, 6%, and 8%. Application of EF slag significantly increased pH, exchangeable Ca and Mg, available-Fe, Mn, Zn, SiO2, and P. Growth and yield of paddy rice with EF slag was better than with silica gel and micro nutrients. Furthermore, the content of heavy metal in rice was very low, so that the rice produced is not harmful and can be consumed.
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Judul: Pengaruh terak baja terhadap sifat kimia tanah serta pertumbuhan dan produksi tanaman Padi (Oryza Sativa) pada tanah gambut dalam dari Kumpeh, Jambi
Abstrak: Serious efforts to achieve self sufficiency in rice to fullfil consumption of population growth in Indonesia become very important. One of the most important problems was the decrease of fertile land in Java along with significant numbers of land conversion to nonagricultural usage. One of the important effort to overcome this problem was utilizing peatlands outside Java. Utilizing of peatland for rice cultivation faces many problems such as soil acidity and toxicity of organic acid which effect to crop growth. Steel slag is a by-product furnace in the process of steel manufacturing. These materials can be used as liming material for improving chemical properties of peat soil. This research purposed to evaluate effect of steel slag on chemical properties of soils and also rice growth and yield. Research was carried out of pot experiment in greenhouse by using peat soils from Kumpeh, Jambi. Slags were applied in dosage 0, 1, 2, 3, 4, and 5% or 0, 30, 60, 90, 120, and 150 g / pot, combined with NPK fertilizer in dosage 50 and 75% from standard, compared with control and standard. The result shows that steel slag significantly improved chemical properties of soils such as raised soil pH, exchangeable Ca and Mg, and available Mn in soils. Toxic heavy metal in rice and soils were given by NPK fertilizer treatment. Steel slag also significantly increased rice yield and growth, reduced unfilled spikelets, and also increased nutrient rate of Ca and Mg in crop. In addition, steel slag reduced usage of conventional fertilizer. This was shown by higher value of fertilizer efficiency on steel slag treatment.
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Judul: Invers dari Matriks Tridiagonal Jacobi
Abstrak: Suatu matriks berukuran n×n dinamakan matriks tridiagonal jika untuk . Karya ilmiah ini memberikan algoritma yang mudah untuk menemukan invers ( dari matriks tridiagonal Jacobi yang simetrik dan nonsimetrik. Setiap elemen pada matriks tridiagonal ini adalah bilangan real. Terdapat 3 lema dan 2 teorema untuk menentukan . Lema pertama menunjukkan persamaan utama dalam membuktikan lema-lema dan teorema-teorema selanjutnya. Invers dari matriks yang simetrik dibuktikan oleh lema kedua yang menunjukkan elemen-elemen baris ke- dari . Selanjutnya, lema kedua dilengkapi dengan teorema pertama yang menunjukkan elemen-elemen dengan . Invers dari matriks yang nonsimetrik dibuktikan oleh lema ketiga yang menunjukkan elemen-elemen dengan dan elemen-elemen dengan dibuktikankan oleh teorema kedua.
Keyword: symmetric, nonsymmetric, matrix