Judul: Pengaruh pemberian kombinasi dosis pupuk dan bahan humat terhadap produksi tandan buah segar kelapa sawit (Elaeis guineensis): studi kasus PTPN VI unit usaha Rimbo Satu, Rimbo Dua, dan Batanghari, Effect of Combined Dosage of Fertilizer and Humic Substances on the Production of Oil Palm Bunches (Elaeis guineensis) (Case Study of PTPN VI Rimbo Satu, Rimbo Dua, and Batanghari Work Units).
Abstrak: Indonesia currently accounts for 47% of oil palm production from various oil palm estates around the world, making Indonesia the number one oil palm producer. Oil palm is one of Indonesia’s eminent agricultural commodities. In comparison to other oil producing plants, such as soybean, olive, coconut, and sunflower, oil palm is the most efficient oil producer. Oil palm can produce oil up to a maximum of 6-8 tons/ha/year. Meanwhile, other sources of oil crops only produce less than 2.5 tons/ha/year, far below the amount produced by oil palm. To obtain optimum production, the characteristics and factors affecting the process should also be optimized effectively and efficiently. One of the factors that influence the production is the fertilizer used during the process. Fertilization is one of the influential factors in planting. It affects plant growth, plant production, and the quality of the product. Fertilization is needed to obtain optimum production of bunches and to produce good quality oil. However, oil palm fertilization requires high cost. Therefore, it needs to be considered to achieve an efficient fertilization. One way to obtain an efficient and effective fertilization is by using humic substances
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Judul: Pengaruh Pupuk NPK Majemuk terhadap Peningkatan Produksi Tandan Buah Segar Kelapa Sawit (Elaeis guineensis Jacq.).
Abstrak: Kelapa sawit merupakan tanaman perkebunan yang memiliki peran penting bagi subsektor perkebunan dan penghasil minyak nabati. Salah satu faktor penting dalam produksi kelapa sawit adalah pemupukan. Kegiatan penelitian ini bertujuan mempelajari pengaruh aplikasi pupuk NPK majemuk terhadap pertumbuhan dan produksi tandan buah segar kelapa sawit. Penelitian dilakukan pada Januari 2023 hingga Maret 2024. Penelitian dilaksanakan di Blok 1 Kebun Pendidikan dan Penelitian Kelapa Sawit IPB-Cargill Kecamatan Jonggol, Kabupaten Bogor. Analisis tanah serta analisis daun dilakukan di Laboratorium Pengujian Departemen Agronomi dan Hortikultura Fakultas Pertanian. Perlakuan disusun dalam 6 taraf pemupukan yaitu: (1) kontrol tanpa aplikasi pupuk (P0), (2) dosis standar sebagai pembanding (P1), (3) 0,5 dosis pupuk NPK 12 12-17 + 2 Mg (P2), (4) 1 dosis pupuk NPK 12-12-17 + 2 Mg (P3), (5) 1,5 dosis pupuk NPK 12-12-17 + 2 Mg (P4), (6) 2 dosis pupuk NPK 12-12-17 + 2 Mg (P5). Data yang diperoleh dianalisis ragam pada taraf α = 0,05 dan dilanjutkan dengan uji DMRT. Perlakuan 1 dosis pupuk NPK majemuk 12-12-17 + 2 Mg dosis yaitu 6,75 kg tanaman-1 tahun-1 menghasilkan bobot tandan buah segar (TBS) 43% lebih baik dibandingkan kontrol, jumlah tandan buah segar (TBS) 2% lebih baik dibandingkan kontrol, dan bobot janjang rata-rata (BJR) 36% lebih baik dibandingkan kontrol. Produktivitas tanaman kelapa sawit pada perlakuan yang diberi perlakuan 1 dosis pupuk NPK majemuk 12-12-17 + 2 Mg dosis yaitu 6,75 kg tanaman-1 tahun-1 menghasilkan produktivitas tertinggi jika dibandingkan dengan kontrol dan perlakuan lainnya yaitu sebesar 36,87 ton ha-1 tahun-1., Oil palm is a plantation crop that has an important role for the plantation subsector and vegetable oil producers. One of the important factors in oil palm production is fertilization. This research activity aims to identify the effect of compound NPK fertilizer application on the growth and production of oil palm fresh fruit bunches. The research was conducted from January 2023 to March 2024. The research was conducted in Block 1 of the IPB-Cargill Oil Palm Education and Research Farm, Jonggol District, Bogor Regency. Soil analysis and leaf analysis were conducted at the Testing Laboratory of the Department of Agronomy and Horticulture, Faculty of Agriculture. Treatments were arranged in 6 fertilizer levels, namely: (1) no fertilizer application (P0), (2) standard NPK fertilizer as a comparison (P1), (3) 0,5 dose of NPK 12-12-17 fertilizer + 2 Mg (P2), (4) 1 dose of NPK 12-12-17 + 2 Mg (P3), (5) 1.5 dose of NPK 12-12-17 + 2 Mg (P4), (6) 2 dose of NPK 12-12-17 + 2 Mg (P5). The data obtained were analyzed for variance at the α = 0,05 level and continued with the DMRT test. The treatment of 1 dose of compound NPK fertilizer 12-12-17 + 2 Mg dose at 6.75 kg plant-1 year-1 produced 43% better fresh fruit bunch (FFB) weight than the control, the number of fresh fruit bunches (FFB) was 2% better than the control, and the average basket weight (BJR) was 36% better than the control. Productivity of oil palm plants in the treatment given 1 dose of compound NPK fertilizer 12-12-17 + 2 Mg at 6.75 kg ha-1 year-1 produced
Keyword: pemupukan, NPK majemuk, produktivitas, tandan buah segar, fertilization, fresh fruit bunch, NPK compound, productivity

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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