Judul: Respon Tanaman Tomat (Lycopersicon esculentum Mill.) terhadap Dosis Pemupukan Berdasarkan Analisis Tanah yang Diapalikasikan melalui Fertigasi
Abstrak: enelitian ini membahas tentang tanaman tomat (Lycopersicon esculentum Mill.), salah satu tanaman hortikultura penting yang banyak dibudidayakan di seluruh dunia. Tanaman tomat memiliki nilai ekonomi dan gizi yang tinggi serta dapat tumbuh dengan baik di berbagai jenis tanah dan iklim. Dalam penelitian ini, fokus diberikan pada pengujian dosis pupuk optimal pada tanaman tomat dengan menggunakan mesin fertigasi. Mesin fertigasi digunakan untuk mengalirkan air dan pupuk secara presisi berdasarkan kebutuhan tanaman tomat. . Penelitian ini bertujuan untuk mengevaluasi pengaruh dosis pupuk urea, SP36, dan KCl dalam sistem fertigasi terhadap pertumbuhan tanaman tomat. Penelitian dilakukan dengan menggunakan lima dosis pupuk yang berbeda, yaitu 0%, 50%, 100%, 150%, dan 200% dari rekomendasi pupuk dosen. Pengumpulan data dilakukan melalui pengamatan pertumbuhan tanaman tomat, seperti tinggi tanaman, jumlah daun, dan berat buah. Percobaan dirancang menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) dan data dianalisis menggunakan regresi untuk mengetahui pengaruh dosis pupuk terhadap hasil panen tanaman tomat. Hasil dari penelitian ini dapat memberikan informasi tentang dosis pupuk terbaik yang dapat digunakan dalam sistem fertigasi untuk meningkatkan pertumbuhan dan hasil panen tanaman tomat. Dosis optimum pemupukan untuk tanaman tomat varietas Gustavi F1 di tanah latosol tercapai pada taraf 157,40% dosis pada taraf P-tersedia sangat rendah (Mehlich 1) dan K-tersedia rendah (Mehlich 1). Dosis pupuk rekomendasi Ferads 100% dapat digunakan karena peningkatan dosis pupuk optimasi tidak meningkatkan produksi secara signifikan., This research discusses tomato plants (Lycopersicon esculentum), one of the important horticultural crops that are widely cultivated worldwide. Tomato plants have high economic and nutritional value and can grow well in various types of soil and climates. In this study, the focus is given to testing the optimal fertilizer dose on tomato plants using fertigation machines. Fertigation machines are used to deliver water and fertilizer precisely based on the needs of tomato plants. This study aims to evaluate the effect of urea, SP36, and KCl fertilizer doses in the fertigation system on tomato plant growth. The study was conducted using five different fertilizer doses, namely 0%, 50%, 100%, 150%, and 200% of the recommended fertilizer dosage by the lecturer. Data collection was carried out through observations of tomato plant growth, such as plant height, leaf number, and fruit weight. The collected data were then analyzed using a Completely Randomized Design (CRD) to determine the effect of fertilizer doses on tomato plant growth. The results of this study can provide information on the best fertilizer dose that can be used in the fertigation system to improve the growth and yield of tomato plants. The optimum fertilization dosage for Gustavi F1 tomato plants in lateritic soil is achieved at a level of 157.40% of the dosage at very low available phosphorus (Mehlich 1) and low available potassium (Mehlich 1) levels. The recommended fertilizer dosage of Ferads 100% can be used because increasing the optimization fertilizer dosage does not significantly improve production.
Keyword: dosis, fertigasi, pertumbuhan, pupuk, tomat

Judul: Optimasi Dosis Pupuk Anorganik dan Pupuk Kandang Ayam pada Budidaya Tomat Hibrida (Lycopersicon esculentum Mill. L.).
Abstrak: The objective of this research was know the effect of fertilizer and manure to growth and productivity of hybrid tomato (Lycopersicon esculentum Mill. L).This research obtained at Pasir Sarongge Experimental Field University Farm Bogor Agricultural University, Cipanas, from February to July 2011. The experimental design used was Completely Randomized Block Design, with two factors and three repetitions. First factor was manure dosages which were 0, 10, 20, and 30 ton ha-1. Second factor was fertilizer dosages which were 0%, 75%, and 150% of recommended dosage. Recommended dosage use was 100 kg ha-1 N, 100 kg ha-1 P2O5, and 50 kg ha-1 K2O, recommendation from Ministry of Agriculture (2002). Plant height showed quadratic response to manure at 2 and 4 week after transplanted (WAT), then linier at 6 WAT. As to fertilizer, plant height showed no response at 2 WAT yet showed linier response at 4 and 6 WAT. Interaction between manure and fertilizer happened at 8 WAT. Manure gave linier response to number of leaves at 2, 4, and 8 WAT but not significant at 6 WAT. Fertilizer gave no significant response at number of leaves. Manure gave quadratic response as fertilizer gave linier response to fruit weight per plot, fruit weight per hectare estimation, and relative yield. Optimal manure dosage given from this research was 24.375 ton ha-1. Maximum fruit weight per plot was 17.41 kg per plot. Maximum fruit weight per hectare estimation was 22.79 ton ha-1. Manure gave linier response to fruit weight per plot of grade A and B. Fruit weight per plot of grade C, fruit diameter, and average fruit weight was not affected by manure or fertilizer given.
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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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