Judul: the Effect of Fertilization on Growth and Production of Three Upland Rice Varietes
Abstrak: Padi gogo merupakan budi daya padi di lahan kering. Produktivitas padi gogo masih rendah. Penelitian ini bertujuan mempelajari pengaruh pemupukan pada pertumbuhan dan produksi Tiga Varietas padi lahan kering. Penelitian dilakukan selama 8 bulan yaitu April-Desember 2019 di Kebun Percobaan IPB Sawah Baru. Rancangan yang digunakan adalah Split plot RKLT dua faktor yaitu petak utama dan anak petak. Petak utama terdiri lima taraf yaitu tanpa pupuk (P0), pupuk hayati + pupuk NPK (P1), pupuk NPK (P2), pupuk organik 5 ton ha-1 + pupuk NPK (P3), pupuk organik 5 ton ha-1 d+ pupuk hayati + NPK (P4). Anak petak tiga taraf yaitu IPB 9G (V1), Inpago 10 (V2), dan Timur (V3). Pemupukan berpengaruh nyata terhadap tinggi tanaman, Bagan Warna Daun, jumlah anakan produktif, jumlah gabah hampa dan bobot gabah per rumpun. Varietas berpengaruh nyata terhadap jumlah anakan pada 5-9 MST, jumlah anakan tidak produktif dan jumlah anakan total., Gogo Rice is type of the rice which could be optimized cultivated in dry land. Unfortunately, the Gogo Rice’s productivity is lowest than the others. The aim of this research is to learn the effect of organic fertilizer to the growth and productivity of rice’s genotypes in dry land. The research takes place at Sawah Baru Research Field with 8 months research duration, May 2019-October 2019. The experiment was conducted in split-plot randomized complete block design with two factors, main plot and sub plot. The main plot consists 5 different fertilizers composition which are no fertilizer (P0), the organic fertilizer + NPK Fertilizer(P1), the NPK Fertilizer (P2), 5 tons ha-1 organic fertilizer + NPK Fertilizer (P3), 5 tons ha-1 organic fertilizer + composite fertilizer + and NPK (P4). The sub plot consists IPB 9G (V1), Inpago 10 (V2), and Timur (V3). The fertilization will affect the growth of the rice after 11 weeks planting with the indicator of color leaf, number of productive leaf, amount of empty rice’s grain, and the weight of collective grain. The sub plot gives significant effect on the number of productive for the period 5-9 weeks after planting, the number of unproductive leaf, and amount of total productive leaf. The best interaction between main plot and sub plot is the combination NPK Fertilizer and Organic Fertilizer.
Keyword: grain, panicle, IPB 9G, Timur

Judul: Respon dua varietas padi gogo terhadap pupuk dan residunya dalam sistem budidaya organik
Abstrak: Irrigation water crisis and the conversion of productive land constantly threaten the productivity of rice. The phenomenon of degradation of land productivity due to excessive synthetic chemical fertilizers in the past has contributed to the limiting factor of rice production. Development of organic-based upland rice on dry land is one alternative solution. Organic cultivation of upland rice needs attention so that the empowerment of local input and the fulfillment of food need can be realized. This experiment aims to determine the effect of organic fertilizer types and its residue on growth and yield components of two varieties of upland rice. Experiments were carried out in two planting seasons. The first growing season used a split-plot design. The main plot consisted of chicken manure (20 tons/ha), Centrosema pubescens (4.3 tons/ha) + chicken manure (10 tons/ha), and Tithonia diversifolia (4.3 tons/ha) + chicken manure (10 tons/ha). Subplot consisted of Situ Patenggang and Limboto varieties. The experiment in the second growing season used a split-split plot design. The main plot consisted of 50 and 100% dosage of fertilizer in the first growing season, the subplots are Danau Gaung and Batu Tegi varieties. Chicken manure; chicken manure + C.pubescens; chicken manure + T.diversifolia give the same effect on the productivity of upland rice in the second growing season. Productivity of upland rice in a row according to the treatment were 1.23,1.26, and 1.19 tons/ha. The use of Tithonia diversifolia gives the best effect on some variables of plant growth and plant resistance to pests and diseases. Limboto variety in the first growing season and Batu Tegi variety in the second growing season are varieties that give the best response to organic fertilizer. Danau Gaung and Batu Tegi varieties have similar yield in the second growing season, with the productivity of each variety is 1.25 and 1.22 ton/ha. Dosage of 50 and 100% resulted similar productivity of upland rice, the productivity given by each dosage is 1.28 and 1.19 ton/ha. Combined treatment of type of organic fertilizer and varieties had the same effect on plant productivity. Fertilizer dosage of 50 and 100 % give the same effect on the components of crop yield in the second growing season. The combination of fertilizer dosage, fertilizer types, and varieties only influenced plant height. Chicken manure, C. pubescens and T. diversifolia can be used as the source of organic fertilizer, depending on the level of difficulty in obtaining the material.
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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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