Judul: Residu pupuk organik mendukung produksi dua varietas kedelai organik (Glycine max (l) merr) di lahan kering
Abstrak: The experiments were conducted at IPB Research Station in Cikarawang, Darmaga,Bogor, from October 2010 to February 2011. The study was conducted to investigate the effect of residues of different organic manures on the production of soybean with 50% dosage in previous experiments. The manure rates were 10 ton chicken manure/ha, 1.75 ton Centrosema pubescens/ha and 1.75 ton Tithonia diversifolia/ha. All treatments were added with 5 ton chicken manure/ha, 1 ton rice husk charcoal/ha and 1 ton dolomite/ha. The experiment used two varieties of soybeans, i.e Anjasmoro and Wilis. This research used Split Plot design with three replication, the organic manure as the main plot and the soybeans varieties as the sub plot. The effect of three organic manure residues were significantly different in number of branch, number of nodule, and filled pod. Organic manure did not significantly affect in productivity of soybeans. The productivity of soybeans with chicken manure, Centrosema pubescens and Tithonia diversifolia were 2.13,1.99 and 2.07 ton/ha. Productivity in the second season was higher than that of first season, it incrased about 83.96%. Varieties were significantly different in filled pod number, 100 seeds weight. The productivity of Anjasmoro was higher than Wilis, they were 2.13 and 1.94 ton/ha, respectively.
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Judul: Two Soybean Varieties Production with The Application Organic Manure with Same Dosage as in Planting Season I under Organic Farming System
Abstrak: Penelitian ini dilakukan untuk mengetahui pengaruh residu pupuk organik terhadap kedelai varietas Wilis dan Anjasmoro pada musim tanam II yang dibudidayakan secara organik. Penelitian dilaksanakan di Kebun Percobaan IPB Cikarawang, Laboratorium Produksi Tanaman Departemen Agronomi dan Horikultura, serta Laboratorium Kimia Tanah, Departemen Ilmu Tanah dan Sumberdaya Lahan, Faperta, IPB pada bulan Oktober 2010 sampai Februari 2011. Rancangan yang digunakan dalam penelitian ini adalah Rancangan Petak Terbagi (Split Plot Design) dua faktor, yaitu pupuk organik dan varietas. Pupuk oganik digunakan sebagai petak utama dan varietas sebagai anak petak. Petak utama terdiri atas tiga jenis perlakuan pupuk organik yaitu 20 ton pupuk kandang ayam/ha, 10 ton pupuk kandang ayam/ha dengan penambahan 3.5 ton Centrosema pubescens/ha dan 10 ton pupuk kandang ayam/ha dengan penambahan 3.5 ton Tithonia diversifolia/ha. Anak petak terdiri atas dua jenis varietas yaitu Anjasmoro dan Wilis. Hasil penelitian ini menunjukkan bahwa perlakuan pupuk organik hanya berpengaruh nyata terhadap kadar Fe biji sedangkan pada komponen pertumbuhan dan produksi lainnya, pupuk organik berpengaruh tidak nyata. Varietas berbeda nyata pada tinggi tanaman umur 2, 3, 5, 6, dan 7 MST, bobot basah dan kering tajuk dan daun 7 MST, jumlah polong isi, jumlah cabang produktif, jumlah buku produktif, bobot 100 biji, kadar Fe dan Zn biji, berbeda sangat nyata pada bobot kering akar 7 MST. Interaksi antara pupuk organik dan varietas hanya berpengaruh nyata terhadap kadar Fe biji. Potensi produksi kedelai dengan pemberian 20 ton pupuk kandang/ha, 10 ton pupuk kandang/ha ditambah 3.5 ton Centrosema pubescens/ha dan 10 ton pupuk kandang ayam/ha ditambah 3.5 ton Tithonia diversifolia/ha berturut-turut adalah 2.43 ton/ha, 2.43 ton/ha, dan 2.26 ton/ha. Potensi produksi kedelai varietas Wilis dan Anjasmoro berturut-turut adalah 2.28 ton/ha dan 2.46 ton/ha.
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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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