Judul: Pengaruh Pemupukan Fosfor terhadap Pertumbuhan dan Produksi Beberapa Varietas Kedelai Hitam (Glycine Soja) pad a Budidaya Jenuh Air di Lahan Pasang Surut
Abstrak: Saturated soil culture is a cultivation that gives continuous irrigation and maintains water depth constantly and makes soil layer in saturated condition. Technology of saturated soil culture has been shown to increase soybean production on tidal swamps. The objective of this experiment to study the effect of phosphorus fertilization on the growth and production variety of soybean under saturated soil culture on tidal swamps. The experiment was conducted at Banyu Urip, Tanjung Lago, Banyuasin, South Sumatera, Indonesia from May to September 2013. The experiment used a split plot design with three replications. The main plot of the experiment is black soybean variety consisted of : Ceneng, Cikuray, Lokal Malang and Tanggamus as control . Sub plot is the dosage of phosphorus fertilization consisted of : 0, 36, 72 and 108 kg P2O5 ha-1. The results showed that the variety and phosphorus fertilization affected soybean productivity. The highest productivity was obtained on Cikuray variety with phosphorus fertilization 108 kg P2O5 ha-1 as much as 4.03 ton ha-1.
Keyword: Tidal Swamp, Saturated Soil Culture, Phosphorus Fertilization, Black Soybean Variety

Judul: Pengaruh Pemberian Abu Sekam, P, dan K terhadap Pertumbuhan dan Produksi Kedelai Hitam pada Budi Daya Jenuh Air di Lahan Pasang Surut
Abstrak: The experiment was carried out to evaluate the effect of husk ash, phosphorus, and potassium fertilizer on the growth and production of black soybean under saturated soil culture on tidal swamps. The experiment was conducted in the tidal swamps of South Sumatera Province, Banyu Urip village, sub District of Tanjung Lago, Banyuasin District, Palembang since April to August 2014. This experiment was using Randomize Complete Block Design with three replications. The concentration of husk ash as the first factor consist of 0, 1 000, 2 000, 3 000 kg ha-1, the concentration of phosphorus fertilizer as the second factor consist of 36 and 72 kg ha-1 P2O5, and the concentration of potassium fertilizer as the third factor consist of 30 and 60 kg ha-1 K2O. Saturated soil culture (SSC) technique was used to support the cultivation of soybeans in tidal swamps. The results showed that the effect of husk ash concentration, interactions of husk ash and phosphorus fertilization, interaction of husk ash and potassium fertilization and interaction of husk ash, phosphorus and potassium fertilization increased the ammount of trifoliat leaves. The optimum combination of 1.26 ton ha-1 husk ash, 36 kg ha-1 P2O5 phosphorus fertilization and 30 kg ha- 1K2O potassium fertilization gave the highest productivity by 4.21 ton ha-1and decreased the dose of Phosphorus and Potassium fertilizer
Keyword: Bogor Agricultural University (IPB), under saturated soil culture, potassium, phosphorus, husk ash, black soybean

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