Judul: Ecological Observation of Kebar Papua Natural Grassland and Productivity Test of Banondit (Biophytum petersianum Klotzsch) with Nitrogen Fertilizer and Defoliation Intervals
Abstrak: The objectives of the study were to observe the ecological aspect of Kebar natural grassland in terms of botanical composition, carrying capacity, association index, species composition, species dominance and banondit productivity due to the effect of nitrogen fertilizer and the different of defoliation interval. The experiment was conducted by using a Factorial Completely Randomize Design with nitrogen fertilizer as the first factor (0, 50, 100, 150 kg N/ha) and the second was defoliation intervals (40, 60, 180 days) with 5 replications. The result of ecological aspect showed that the botanical composition was consisted of Imperata cylindrica (59%), weed (24%), banondit (9%) and legume (8%). Imperata cylindrica was a dominant species in Kebar Natural pasture with high value of important index (INP) (31.05), species diversity was less than one and they have high related association (0.67-0.70) beside banondit and the other species. Prediction of carrying capacity for the area of 622.2 ha was 777.75 AU/ha/year. Increasing nitrogen fertilizer up to 150 kg/ha and interval of defoliation 180 days resulted better performance than the other treatment combination. This treatment showed an increased in plant high, number of ligule leaves, fresh and dry weight of crown, dry matter production and organic matter constituent. Thus, banondit was found as a potential source for feed.
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Judul: Kajian Hasil-Hasil Penelitian tentang Respon Pemberian Pupuk NPK terhadap Pertumbuhan Berbagai Semai dan Bibit Tanaman Kehutanan
Abstrak: The reforestation program is currently intensively implemented in Indonesia. However, its success rate is low. This is because most of the lands are of poor soil having lack of humus. One effort to increase the success of the program is the supply of quality seeds and fertilization. Collecting the results of research on the application of NPK fertilizer to forest plants is needed to determine the effectiveness of fertilizer on the plant growth. This study was done by collecting and analyzing the results of the research on the effect of NPK fertilizer on the growth of various forestry seedlings. The research data was taken from the library of the Forestry Faculty, Bogor Main Library (LSI) of Bogor Agricultural University, and Ardi Koesoema Library of R.I (the republic of Indonesia). Interviews were also conducted with the farmers of forest plant nursery as well as forestry researchers to collect the data. Forest plant species observed were Shorea ovalis, Dipterocarpus hasseltii, Paraserianthes falcataria, Khaya anthoteca, Anthocephalus cadamba, Acacia mangium, Eugenia polyantha, Gmelina arborea, Maesopsis eminii, Enterolobium cyclocarpum, Swietenia macrophylla, Agathis lorantifolia, and Toona sureni. The research results showed that NPK fertilizer could improve the quality of forest seedlings in the nursery. In addition, NPK fertilizer can improve the growth rate of seedlings planted on gold tailing and field. The result of the interview showed that some farmers used NPK on the nursery. The decision whether or not to use such fertilizer was based on the calculation of economic value and the experience of farmer. On the ather hand, the researchers viewed that fertilization should be done to help the soil providing complete and balanced nutrients for the plants to grow.
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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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