Judul: The Effect of Organic Fertilizer Type and Inorganic Fertilizer Dose on Production and Sweetness Level of Sweet Corn (Zea mays saccharata Sturt.)
Abstrak: Jagung manis merupakan tanaman yang memiliki nilai ekonomi yang tinggi karena dapat dijadikan sebagai bahan pangan atau bahan baku industri. Peningkatan impor jagung manis dari tahun 2019 sampai 2021 menandakan bahwa produksi jagung manis nasional belum dapat mencukupi permintaan pasar. Pemupukan yang tepat akan meningkatkan hasil produksi jagung. Penelitian ini bertujuan mengetahui pengaruh jenis pupuk organik dan dosis pupuk anorganik yang paling efektif dalam meningkatkan produksi dan tingkat kemanisan jagung manis. Percobaan dilaksanakan pada bulan November 2023 hingga bulan Januari 2024 di Kebun Percobaan sawah baru, Departemen Agronomi dan Hortikultura, Fakultas Pertanian, Institut Pertanian Bogor. Penelitian ini menggunakan rancangan split-plot RKLT dengan tiga kali ulangan. Jenis pupuk organik sebagai petak utama dan dosis pupuk anorganik sebagai anak petak. Dua jenis pupuk organik, pupuk kandang ayam dan pupuk kompos sapi dikombinasikan dengan dosis pupuk anorganik 0%, 50% 100%, dan 150% dosis pupuk acuan. Dosis pupuk anorganik 150% memberikan pengaruh terbaik terhadap karakter vegetatif dan produksi hasil jagung manis dengan produktivitas sebesar 10,9 ton ha-1. Pada penelitian ini pemupukan tidak berpengaruh nyata terhadap tingkat kemanisan jagung manis (brix)., IRSYAD RIFHANDI. The Effect of Organic Fertilizer Type and Inorganic Fertilizer Dose on Production and Sweetness Level of Sweet Corn (Zea mays saccharata Sturt.). Supervised by CANDRA BUDIMAN and PURWONO. Sweet corn is a plant that has high economic value because it can be used as food or industrial raw materials. The increase in sweet corn imports from 2019 to 2021 indicates that national sweet corn production has not been able to meet market demand. This study aims to determine the effect of the type of organic fertilizer and the dose of inorganic fertilizer that is most effective in increasing the production and sweetness level of sweet corn. The experiment will be carried out from November 2023 to January 2024 at the new rice field experimental garden, Department of Agronomy and Horticulture, Faculty of Agriculture, Bogor Agricultural University. This study used a split-plot RKLT design with three repeats. Type of organic fertilizer as the main plot and dose of inorganic fertilizer as a child plot. Two types of organic fertilizers, chicken manure and cow compost are combined with a dose of 0% inorganic fertilizer, 50% 100%, and 150% dose of reference fertilizer. The dose of 150% inorganic fertilizer has the best influence on the vegetative character and yield production of sweet corn with a productivity of 10,9 tons ha-1. In this study, fertilization did not have a real effect on the sweetness level of sweet corn (brix).
Keyword: fertilization, brix, productivity

Judul: Combination Effect of Biofertilizer, Organic Fertilizer, and NPK Fertilizer on Sweet Corn (Zea mays saccharata Sturt.) Yield
Abstrak: Jagung manis (Zea mays saccharata Sturt.) merupakan salah satu bahan pangan. Produktivitas jagung manis dapat ditingkatkan melalui teknologi pemupukan yang tepat. Tujuan penelitian ini adalah mempelajari pengaruh kombinasi pupuk hayati, pupuk organik, dan pupuk NPK terhadap hasil jagung manis. Penelitian disusun menggunakan rancangan acak lengkap teracak (RKLT) faktor tunggal yaitu kombinasi pupuk. Hasil penelitian menunjukkan perlakuan kombinasi pupuk berpengaruh nyata meningkatkan nilai brix dan diameter tongkol jagung manis. Pemupukan dengan pupuk hayati+organik+NPK 50% dosis memberikan nilai diameter tongkol tertinggi yaitu sebesar 5,1 cm, 10,9% lebih tinggi dibandingkan kontrol dan 6,25% lebih tinggi dibandingkan perlakuan pupuk hayati+organik tanpa pupuk NPK. Hal ini menunjukkan bahwa pemberian pupuk NPK masih diperlukan disamping aplikasi pupuk organik dan pupuk hayati. Pemupukan organik saja memberikan hasil tertinggi terhadap tingkat kemanisan jagung manis dengan nilai 16,8% brix, 15,9% lebih tinggi dibandingkan perlakuan pupuk NPK 100% dosis., Sweet corn (Zea mays saccharata Sturt.) is one of food source. Sweet corn productivity can be improved through right fertilization technology. The aim of this research was to study the effect of combination of biofertilizer, organic fertilizer, and NPK fertilizer on sweet corn productivity. Research used a Randomized Complete Block Design (RCBD) with single factor i.e. combination of fertilizer. The result showed that combination of fertilizer treatment had significant effect on the increase of ear diameter and sweetness level. Fertilization by biofertilizer+organic fertilizer+ NPK 50% doses improved ear diameter to 5.1 cm or 10.9% higher than the control treatment and 6.25% higher than fertilization by biofertilizer+organic no NPK fertilizer. It is shown that NPK fertilizer is needed beside organic fertilizer and biofertilizer. The organic fertilization only affect highest sweetness level with 16.8 % brix or 15.9% higher than NPK 100% doses treatment.
Keyword: brix, ear diameter, fertilization

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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