Judul: Respon Kombinasi Pupuk Organik dan Anorganik terhadap Produksi dan Kualitas Hasil Panen Katuk (Sauropus androgynous (L.) Merr.)
Abstrak: Katuk (Sauropus androgynus (L.) Merr.) adalah salah satu tanaman indigenous yang berpotensi untuk menjadi sayuran daun bernutrisi tinggi dan memiliki manfaat antibakteri, antianemia, antiinflamasi, memperlancar ASI, pewarna alami, serta ramuan obat tradisional. Penelitian ini bertujuan untuk mengetahui respon kombinasi pupuk organik dan anorganik pada produksi dan kualitas hasil panen tanaman katuk serta dosis optimumnya. Penelitian ini dilaksanakan pada bulan Juni-November 2020 di Kebun Percobaan Leuwikopo IPB, Dramaga, Bogor, Jawa Barat. Percobaan dilakukan dengan menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) faktor Split Plot dengan pupuk urea sebagai petak utama dan pupuk kandang sebagai anak petak. Pupuk urea terdiri dari tiga taraf perlakuan, yaitu N1 (100 kg ha-1), N2 (200 kg ha-1), dan N3 (300 kg ha-1). Pupuk kandang terdiri dari dua taraf, yaitu P1 (20 ton ha-1) dan P2 (30 ton ha-1). Penelitian dilakukan dengan empat ulangan sehingga diperoleh enam kombinasi dengan 24 satuan percobaan. Hasil penelitian menunjukkan bahwa terdapat interaksi pupuk urea dan pupuk kandang pada peubah bobot daun layak konsumsi, bobot basah daun, bobot kering daun, dan bobot panen per petak. Kombinasi pupuk urea dan pupuk kandang pada N1P1 (100 kg ha-1 urea + 20 ton ha-1 pukan), N3P1 (300 kg ha-1 urea + 20 ton ha-1 pukan), dan N1P2 (100 kg ha-1 urea + 30 ton ha-1 pukan) terbukti meningkatkan bobot basah daun, bobot kering daun, dan bobot panen petak. Pada percobaan dengan dua kali pemanenan ini dapat menggunakan kombinasi N1P1 (100 kg ha-1 urea + 20 ton ha-1 pukan) untuk praktik budidaya katuk yang efisien dan hemat biaya., Katuk (Sauropus androgynus (L.) Merr.) is one of the indigenous plants that has the potential to become a leaf vegetable with high nutrition and has antibacterial, antianemic, anti-inflammatory benefits, facilitates breast milk, natural dyes, and traditional medicinal ingredients. This study aims to determine the response of the combination of organic and inorganic fertilizers on the production and quality of katuk crop yields and the optimum dose. This research was conducted in June-November 2020 at the Leuwikopo Experimental Station, IPB, Dramaga, Bogor, West Java. The experiment was carried out using a Completely Randomized Block Design (CRBD) with Split Plot factor with urea as the main plot and manure as the sub-plots. Urea fertilizer consisted of three treatment levels, namely N1 (100 kg ha-1), N2 (200 kg ha-1), and N3 (300 kg ha-1). Manure consists of two levels, namely P1 (20 tons ha-1) and P2 (30 tons ha-1). The study was conducted with four replications so that six combinations were obtained with 24 experimental units. The results showed that there was an interaction between urea fertilizer and manure on the variables of leaf weight suitable for consumption, leaf wet weight, leaf dry weight, and harvest weight per plot. Combination of urea and manure in N1P1 (100 kg ha-1 urea + 20 tons ha-1 manure), N3P1 (300 kg ha-1 urea + 20 tons ha-1 manure), and N1P2 (100 kg ha-1 urea + 30 tons ha-1 manure) was shown to increase leaf wet weight, leaf dry weight, and plot harvest weight. In this experiment with two harvests, a combination of N1P1 (100 kg ha-1 urea
Keyword: katuk, kualitas hasil panen, produksi, pupuk kandang, urea

Judul: Effect of Fertilization Dosage on Growth and  Production of Katuk (Sauropus androgynus) Cuttings Using Fertigation Through  Drip Irrigation
Abstrak: Keberadaan tanaman indigenous dapat menambah pilihan jenis sayuran sebagai konsumsi masyarakat. Salah satu tanaman yang masuk dalam tanaman indigenous adalah katuk. Untuk menunjang pertumbuhan tanaman katuk yang maksimal diperlukan adanya aplikasi pemupukan dan penyiraman yang efisien. Penelitian ini bertujuan mengetahui dosis pemupukan yang optimal pada budidaya katuk. Kegiatan penelitian dilaksanakan mulai bulan November 2022 hingga April 2023 di Kebun Percobaan Leuwikopo. Percobaan dilakukan dengan metode rancangan kelompok lengkap teracak sebanyak tiga kali ulangan. Penelitian terdiri dari faktor tunggal yaitu dosis pupuk N, P, dan K dengan lima taraf dosis (0%, 50%, 100%, 150%, 200%). Hasil penelitian menunjukkan bahwa pengaruh dari pemupukan tidak memberikan respon yang nyata, kecuali pada peubah tinggi cabang pada umur tanaman 10-13 MST. Meskipun tidak berpengaruh nyata, terdapat indikasi bahwa bobot basah, bobot daun, dan produktivitas total akan meningkat seiring peningkatan dosis pupuk yang diberikan., The existence of indigenous plants can increase the choice of vegetables for public consumption. One of the indigenous plants is katuk. To support the maximum growth of katuk plants, efficient fertilization and watering applications are needed. This study aims to determine the optimal dose of fertilization in katuk cultivation. Research activities were carried out from November 2022 to April 2023 at the Leuwikopo Experimental Garden. The experiment was conducted using a randomized complete group design method with three replications. The research consisted of a single factor, namely the dose of N, P, and K fertilizers with five dose levels (0%, 50%, 100%, 150%, 200%). The results showed that the effect of fertilization did not give a real response, except for the variable of branch height at plant age 10-13 weeks after planting. Although not significantly affected, there are indications that wet weight, leaf weight, and total productivity will increase as the dose of fertilizer applied increases.
Keyword: indigenous vegetables, inorganic fertilizer, 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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