Judul: Effectiveness of Polyhalite Based Compound Fertilizer on Corn Plants (Zea mays L. Saccharata).
Abstrak: Jagung merupakan tanaman yang dikonsumsi terbanyak kedua setelah padi di Indonesia. Produktivitas jagung perlu ditingkatkan karena kebutuhan akan jagung semakin meningkat. Salah satu cara yang bisa dilakukan adalah menggunakan pupuk yang sesuai dosis rekomendasi. Pupuk majemuk dinilai dapat meningkatkan produksi dan menambah efesiensi dalam praktik budidaya skala luas. Pupuk majemuk berbasis polyhalite merupakan pupuk majemuk yang mengandung 15,5% K2O, 16,5% CaO, 7,3% MgO and 9,3% S. Penelitian dilaksanakan di Kebun Percobaan IPB Sindangbarang Sabisa Farm, Kota Bogor, Jawa Barat selama 4 bulan, dari bulan Januari hingga April 2023. Percobaan ini menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) dengan 1 faktor. Perlakuan dosis pupuk disusun dalam 6 taraf pemupukan yaitu: (1) perlakuan kontrol tanpa pupuk K, (2) perlakuan pembanding (NPK standar), (3) perlakuan 0,5 dosis pupuk uji, (4) perlakuan 1,0 dosis pupuk uji, (5) perlakuan 1,5 dosis pupuk uji, (6) perlakuan 2,0 dosis pupuk uji. Hasil dari penelitian ini terhadap pertumbuhan vegetatif seluruhnya tidak berbeda nyata. Pada hasil generatif hasil tertinggi dicapai oleh perlakuan P5, dan memiliki nilai efektivitas agronomi relatif (EAR) 103%, lebih tinggi dibandingkan perlakuan standar (P2) yang bernilai 100%., Corn is the second most consumed crop after rice in Indonesia. Corn productivity needs to be increased because the need for corn is increasing. One way that can be done is to use fertilizer according to the recommended dose. Compound fertilizers are considered to be able to increase production and increase efficiency in large-scale cultivation practices. Compound fertilizer such as polyhalite-based compound macro fertilizer containing 15,5% K2O, 16,5% CaO, 7,3% MgO and 9,3% S. The research was carried out at the IPB Sindangbarang Sabisa Farm Experimental Field, Bogor City, West Java for 4 months, from January to April 2023. This trial uses a Randomized Complete Block Design (RCBD) with 1 factor. The fertilizer dose treatment was arranged in 6 levels of fertilization, namely: (1) control treatment without K fertilizer, (2) comparison treatment (standard NPK), (3) treatment with 0.5 dose of test fertilizer, (4) treatment with 1.0 dose of test fertilizer, (5) treatment with 1.5 doses of test fertilizer, (6) treatment with 2.0 doses of test fertilizer. The results of this research on vegetative growth were not significantly different. In terms of generative results, the highest results were achieved by the P5 treatment, and it had a relative agronomic effectiveness (RAE) value of 103%, higher than the standard treatment (P2) which had a value of 100%.
Keyword: Jagung, Pemupukan, Polyhalite, Pupuk majemuk

Judul: The Effect of Potassium on the Growth and Productivity of Sweet Corn (Zea mays saccharata. Sturt)
Abstrak: Pemanfatan jagung manis yang masih banyak digunakan di Indonesia baik sebagai bahan makanan maupun bahan baku industri menyebabkan permintaannya semakin meningkat. Upaya peningkatan produktivitas jagung manis dapat dilakukan melalui teknik budidaya yang baik, salah satunya dengan pemberian pupuk kalium yang tepat. Penelitian bertujuan untuk mendapatkan dosis pupuk kalium yang dapat meningkatkan pertumbuhan dan produktivitas jagung manis. Penelitian dilakukan pada bulan November 2023 hingga Januari 2024 di Kebun Sabisa Farm IPB, Sindang Barang, Kota Bogor. Rancangan percobaan yang digunakan dalam penelitian ini adalah Rancangan Kelompok Lengkap Teracak (RKLT) faktor tunggal. Percobaan ini menggunakan satu faktor perlakuan pupuk kalium jenis MOP dengan 6 taraf perlakuan yaitu tanpa pemberian pupuk (kontrol), NPK standar (300 kg ha-1 urea, 200 kg ha-1 SP-36, dan 200 kg ha-1 KCl), 100 kg ha-1MOP, 200 kg ha-1MOP, 300 kg ha-1MOP, dan 400 kg ha-1 MOP. Percobaan diulang sebanyak 4 kali sehingga terdapat 24 satuan percobaan. Penelitian menunjukkan bahwa perlakuan dosis pupuk kalium pada jagung manis memiliki pengaruh nyata terhadap bobot brangkasan segar, bobot tongkol berkelobot, panjang tongkol, dan estimasi panen tanaman contoh pada jagung manis dengan nilai Relative Agronomic Effectiveness (RAE) diatas 95% pada perlakuan 200 kg ha-1 MOP., Sweet corn ultilization is still widely used in Indonesia both as food and industrial raw material causing its demand to increase. Efforts to increase sweet corn productivity can be done through good cultivation techniques, one of which is by applying the right potassium fertilizer. The study aimed to obtain the dosage of potassium fertilizer that can increase the growth and productivity of sweet corn. The research was conducted from November 2023 until January 2024 at Sabisa Farm IPB, Sindang Barang, Bogor City. The experimental design used in this study was a single-factor Randomized Complete Block Design (RCBD). This experiment used one treatment factor of MOP potassium fertilizer with 6 treatment levels, namely no fertilizer (control), standard NPK (300 kg ha-1 urea, 200 kg ha-1 SP-36, and 200 kg ha-1 KCl), 100 kg ha-1 MOP, 200 kg ha-1 MOP, 300 kg ha-1 MOP, and 400 kg ha-1 MOP. The experiment was repeated 4 times so that there were 24 experimental units. The study showed that the treatment of potassium fertilizer doses in sweet corn had a significant effect on fresh stover weight, cob weight, cob length, and estimated harvest of sample plants in sweet corn with Relative Agronomic Effectiveness (RAE) values above 95% in the 200 kg ha-1 MOP treatment.
Keyword: pupuk MOP, kalium, produksi, RAE., MOP fertilizer, potassium, production, RAE.

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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