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: Growth and Productivity of Upland Rice from Different Plant Spacing under Productive Oil Palm Plantation
Abstrak: Konsumsi beras yang tinggi seiring dengan meningkatnya jumlah penduduk menjadi tantangan tersendiri bagi Pemerintah Indonesia untuk memenuhi kebutuhan beras. Salah satu upaya yang dapat dilakukan untuk menunjang produktivitas beras adalah menanam padi gogo sebagai tanaman sela di perkebunan. Penelitian ini bertujuan untuk membandingkan varietas dan jarak tanam terhadap pertumbuhan serta hasil padi gogo di bawah naungan kelapa sawit menghasilkan. Penelitian ini dilakukan pada bulan Maret hingga Agustus 2023 di Kebun Percobaan IPB Cikabayan, Dramaga, Bogor. Penelitian ini menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) dua faktor yaitu perlakuan varietas dan jarak tanam. Varietas yang digunakan adalah IPB 9G, IPB 8G, Inpago 12, dan Situ Bagendit. Perlakuan jarak tanam menggunakan jarak tanam 5 cm x 5 cm, 10 cm x 10 cm, 15 cm x 15 cm, dan 20 cm x 20 cm. Hasil penelitian menunjukkan perlakuan varietas berpengaruh nyata terhadap persentase tanaman hidup, tinggi tanaman, jumlah anakan, dan jumlah anakan produktif dengan varietas IPB 9G menunjukkan hasil secara keseluruhan lebih baik. Perlakuan jarak tanam tidak memberikan pengaruh nyata pada semua parameter pengamatan tetapi jarak tanam 20 cm x 20 cm memberikan hasil yang lebih konsisten dibandingkan ketiga jarak tanam lainnya. Kedua perlakuan tidak menunjukkan interaksi yang nyata pada semua parameter pengamatan. Pertumbuhan dan hasil pada padi gogo dibawah naungan kelapa sawit diduga dipengaruhi oleh intensitas cahaya., The higher rice consumption along with the increasing population rate in Indonesia has become a challenge for the Indonesian Government in fulfilling the country’s rice needs. One way to support the rice productivity is to planting upland rice as an intercrop in plantation. This study aims to compare multiple varieties and plant spacing for the growth and productivity of the upland rice under the shade of palms oil plants. The research was conducted from March until August 2023 at Cikabayan Experimental Field of IPB, Dramaga, Bogor. This study used a completely randomized block design two factorial with different varieties and plant spacing. The varieties used in this study were IPB 9G, IPB 8G, Inpago 12, and Situ Bagendit. The plant spacing used in this study were 5 cm x 5 cm, 10 cm x 10 cm, 15 cm x 15 cm, and 20 cm x 20 cm. the result showed the variety treatment has significantly affected the percentage of live plants, plants height, number of tillers, and productive tillers with IPB 9G showing the most consistent result compared to the other varieties. Plant spacing treatment did not show significant differents on all of the observation parameter but the 20 cm x 20 cm spacing showed the better result among the plant spacing treatments. neither the varieties nor plant spacing treatments showed significant interaction in any of the observation parameters. The growth and productivity of upland rice under the shade of palms oil plants can be affected by the light intensity.
Keyword: plant spacing, upland rice, varieties

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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