Judul: Pengaruh Pupuk Kandang dan NPK pada Tanaman Suweg, Talas, dan Iles-Iles
Abstrak: Tuber crops play important role in food security status in Indonesia. In order to increase productivity, study was conducted on suweg, taro, and iles-iles treated with manure and NPK fertilizers. Research was carried out in Cikabayan, University Farm of IPB from December 2009 to July 2010. Tubers were planted under 50% shading net. Split plot design with two factors was used in this reseach. Goat manure with three levels, i.e., 0 ton/ha, 5 ton/ha, dan 10 ton/ha was determined as main plot. As subplot, NPK fertilizers, was applied at four levels, i.e., zero, 100:60:80 kg/ha, 125:60:100 kg/ha, and 150:60:120 kg/ha. The results showed that there was interaction between manure and NPK on leaf number, petiole height, petiole diameter, and fresh mass of suweg. Aplication of 10 tons/ha of manure without NPK produced the highest fresh mass of suweg corm. Interaction was significant for leaf number and petiol height of taro and iles-iles, and petiol diameter and rachis length of iles-iles. There was not interaction between manure and NPK fertilizer for fresh mass corm of both taro and iles-iles.
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Judul: Peningkatan pertumbuhan dan hasil panen beberapa tanaman sayuran daun melalui aplikasi pupuk kandang berfortifikasi.
Abstrak: The objective of this research was to study the effect of fortified animal manure application on growth and yield of several leafy vegetables, such as: kangkong (Ipomoea aquatica F.), caisin (Brassica rapa L.), and lettuce (Lactuca sativa L.). This research was conducted at Cikabayan Farm Unit, University Farm, IPB Darmaga Bogor from Februari to August, 2012. Six treatments (chicken manure, fortified chicken manure, goat manure, fortified goat manure, cow manure, fortified cow manure) were arranged in Randomized Complete Block Design with four replication for each vegetables as a single unit experiment. Chicken manure application produced higher yield. Chicken manure application produced 4.88 ton ha-1 kangkong, 9.60 ton ha-1 caisin, and 2.24 ton ha-1 lettuce. Moreover, the application of fortified animal manure increased kangkong yield up to 20% weight per plant, 17.78% marketable plant weight per bed and 19.76% root weight per plant.
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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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