Judul: Effect of Mulching on Several Genotypes of Kidney  Beans (Phaseolus vulgaris L.) in the Lowlands
Abstrak: Kacang merah cocok ditanam dengan ketinggian 1000 – 1500 m dpl. Luas lahan kacang merah pada dataran tinggi mengalami penurunan setiap tahunnya. Kacang merah berpotensi untuk dikembangkan di dataran rendah dengan modifikasi iklim mikro. Penanaman di dataran rendah dapat memberikan keuntungan yang lebih tinggi karena lebih dekat kepada konsumen. Modifikasi iklim mikro yang digunakan yaitu penggunaan mulsa yang memberikan kondisi yang cenderung sesuai bagi tanaman kacang merah seperti suhu dan kelembaban sehingga tanaman kacang merah dapat tumbuh dan berkembang dengan baik. Penelitian ini bertujuan untuk mempelajari respon genotipe kacang merah terhadap perlakuan mulsa, interaksi genotipe dengan perlakuan mulsa terhadap produksi, dan seleksi genotipe terbaik. Penelitian dilakukan pada September 2023 sampai Januari 2024 di Kebun Percobaan Leuwikopo IPB, Ciampea, Bogor. Rancangan yang digunakan dalam penelitian yaitu RKLT Pola Tersarang (nested design) dengan dua faktor. Faktor pertama adalah perlakuan mulsa dengan dua taraf yaitu dengan mulsa dan tanpa mulsa, faktor kedua adalah genotipe dengan 7 genotipe kacang merah. Hasil penelitian menunjukkan bahwa perlakuan mulsa berpengaruh sangat nyata terhadap karakter cabang produktif, panjang polong, panjang tangkai polong, jumlah biji perpolong, bobot basah polong, bobot kering polong, bobot kering biji, jumlah polong, dan umur berhenti berbunga kacang merah. Interaksi antara genotipe dengan perlakuan mulsa menunjukkan peningkatan pada panjang tangkai polong, bobot basah polong, bobot kering polong, bobot kering biji, jumlah polong, dan umur berhenti berbunga. Genotipe terbaik yaitu KM58 yang memiliki panjang tangkai polong tertinggi perlakuan dengan mulsa dan tanpa mulsa, bobot kering polong tertinggi perlakuan dengan mulsa dan tanpa mulsa, dan bobot kering biji tertinggi perlakuan mulsa dan tanpa mulsa., Kidney beans are suitable for cultivating at an altitude of 1000 – 1500 m above sea level. The area of kidney bean land in the highlands decreases every year. Kidney beans have the potential to be developed in the lowlands with microclimate modification. Planting in the lowlands can get higher profits because it is closer to consumers. The microclimate modification used is the use of mulch which provides conditions that tend to be suitable for kidney bean plants such as temperature and humidity so that kidney bean plants can grow and develop well. This research aims to study the response of kidney bean genotypes to mulch treatment, the interaction of genotypes with mulch treatment on production, and the selection of the best genotype. The research was conducted from September 2023 to January 2024 at the Leuwikopo IPB Experimental Garden, Ciampea, Bogor. The design used in the research is the Nested Pattern RKLT (nested design) with two factors. The first factor is mulching treatment with two levels, namely with mulch and without mulch, the second factor is a genotype with 7 levels bean genotypes. The results of the research showed that mulch treatment had a very significant effect on the character of productive branches, pod length, pod stalk length, number of seeds per pod, pods of pods, dry weight of pods, dry weight of seeds, number of pods, and the age at which kidney beans stopped flowering. The interaction between genotype and mulch treatment showed an increase in pod stalk length, pods, pod dry weight, seed
Keyword: iklim mikro, Irigasi Tetes, protein, cekaman fisik, rancangan tersarang

Judul: The Effect of the Type of Mulch and the Dosage of Goat Manure Compost on the Growth and Production of Green Beans (Phaseolus vulgaris L.)
Abstrak: Kebutuhan pangan khususnya kacang buncis di masa mendatang akan semakin meningkat, karena memiliki sumber protein nabati yang tinggi dan kaya akan vitamin sehingga banyak digemari masyarakat. Produktivitas kacang buncis masih mengalami fluktuasi setiap tahunnya. Hal ini terjadi karena penggunaan benih unggul yang belum merata dan teknik budidaya yang belum optimal. Penelitian ini bertujuan meningkatkan produktivitas kacang buncis melalui pemberian pupuk kompos kotoran kambing dan penggunaan mulsa pada taraf dan dosis pupuk yang tepat. Rancangan penelitian yang digunakan adalah Rancangan Kelompok Lengkap Teracak dengan dua faktor yaitu jenis mulsa dan dosis pupuk kompos kotoran kambing, setiap perlakuan terdiri dari 3 ulangan. Jenis mulsa berpengaruh nyata terhadap tinggi tanaman, diameter batang, jumlah daun, jumlah cabang, luas daun, bobot basah batang, bobot basah daun, bobot kering batang, bobot kering daun, jumlah polong per tanaman, panjang polong, bobot polong per tanaman, bobot polong per petak dan produktivitas tanaman. Perlakuan MPHP merupakan jenis mulsa terbaik dan efisien dalam meningkatkan pertumbuhan dan produksi tanaman. Dosis pupuk kompos kotoran kambing nyata dapat meningkatkan semua parameter pertumbuhan dan produksi tanaman kecuali bobot basah dan bobot kering akar. Terdapat interaksi antara jenis mulsa dan dosis pupuk kompos kotoran kambing terhadap bobot polong per tanaman, bobot polong per petak dan produktivitas tanaman. Perlakuan MPHP dengan dosis pupuk kompos 25 ton ha-1 nyata dapat meningkatkan 87,12% produktivitas buncis dibanding MPHP tanpa perlakuan pupuk. Dosis pupuk kompos optimal pada penggunaan MPHP yaitu 24,95 ton ha 1., The future demand for food, especially kidney beans, will continue to rise due to its high plant-based protein source and rich vitamin content, making it highly favored by the community. The productivity of kidney beans still experiences fluctuations every year. This occurs due to uneven distribution of superior seeds and suboptimal cultivation techniques. This study aimed to enhance kidney bean productivity through the application of goat manure compost fertilizer and the use of mulch at the appropriate level and dosage of fertilizer. The research design used was a Completely Randomized Group Design with two factors, namely, types of mulch and dosage of goat manure compost fertilizer. Each treatment consisted of 3 replications. The type of mulch significantly affected plant height, stem diameter, leaf count, branch count, leaf area, wet weight of stem, wet weight of leaves, dry weight of stem, dry weight of leaves, number of pods per plant, pod length, pod weight per plant, pod weight per plot, and plant productivity. The MPHP treatment proved to be the most effective and efficient mulch type in enhancing plant growth and production. The dosage of goat manure compost fertilizer significantly improved all growth and production parameters of the plants except for wet weight and dry weight of roots. There was an interaction between the type of mulch and the dosage of goat manure compost fertilizer concerning pod weight per plant, pod weight per plot, and plant productivity. MPHP treatment with a compost fertilizer dose of 25 tons per hectare can significantly increase 87,12% of chickpea productivity compared to MPHP without fertilizer treatment. The optimal dose of compost fertilizer in the use of MPHP is 24,95 tons per hectare.
Keyword: compost, organic mulch, synthetic mulch

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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