Judul: Optimization of AB Mix Fertilizer Concentration on Growth and Harvest Quantity of Erina F1 Cucumber Variety in Pot Cultivation
Abstrak: Mentimun merupakan tanaman sayur yang dikonsumsi buahnya. Tujuan penelitian ini adalah memperoleh konsentrasi pupuk optimum untuk pertumbuhan dan kuantitas mentimun varietas erina F1 pada budidaya di dalam pot. Media tanam yang digunakan adalah campuran arang sekam dan pupuk kandang dengan perbandingan 1 kg : 1 kg. Terdapat 3 taraf konsentrasi AB Mix yang diuji yaitu 2 ml L-1, 3 ml L-1, dan 4 ml L-1serta ditambah 1 taraf kontrol tanpa pemupukan. Pemberian pupuk diberikan dengan cara fertigasi sebanyak 250 ml per hari. Penelitian berlangsung dari bulan Juni hingga Agustus 2020 dan berlokasi di Kelurahan Purwokerto Lor, Kecamatan Purwokerto Timur, Kabupaten Banyumas. Pengamatan vegetatif dilakukan sebanyak 1 kali dalam seminggu hingga tanaman berumur 4 MST, sedangkan pengamatan panen berlangsung dari tanggal 1-27 Agustus 2020 dengan intensitas pengamatan sebanyak 2 hari sekali. Setelah data diperoleh kemudian dilakukan uji sidik ragam satu arah terhadap data tersebut. Hasil dari analisis uji sidik ragam membuktikan bahwa tidak ada pengaruh nyata dari perlakuan terhadap pertumbuhan dan produksi tanaman. Hal ini disebabkan oleh kurangnya pemberian air bagi tanaman yang mengakibatkan pemupukan yang tidak efektif untuk pertumbuhan tanaman. Media tanam yang memiliki daya pegang air yang rendah menyebabkan air dan nutrisi tidak tersedia cukup untuk tanaman., Cucumber is a vegetable plant that is consumed forits fruit. This study aimed to obtain the optimum fertilizer concentration for growth and harvest quantity Erina F1 cucumber varieties in pot cultivation. The planting medium used was a mixture of husk charcoal and manure with a ratio of 1 kg : 1 kg. There were 3 AB Mix concentration levels tested, namely 2 ml L -1 , 3 ml L -1 , and 4 ml L -1 , and added 1 level of control without fertilizer. Fertilizer (250 ml per day per pot) was applied by fertigation. The research took place in Purwokerto Lor Village, East Purwokerto District, Banyumas Regency, from June to August 2020. Vegetative observations were carried out once a week until four weeks after fertilizer application. While harvest observations were carried from 1-27 August 2020, the frequency of harvest observations was every two days. After the data were obtained, a one-way variance test was carried out on the data. The variance test proved that there was no significant effect of the treatment on plant growth and production. These results are caused by the lack of water supply for plants, which resulted in ineffective fertilization for plant growth. Planting media that have low water holding capacity caused insufficient water and nutrient for the plants.
Keyword: AB mix, concentration, planting media, cucumber, pots

Judul: Optimization of Fertilization Dose in Eggplant Cultivation using Fertigation through Drip Irrigation
Abstrak: Terung banyak dibudidayakan di Indonesia namun masih memiliki angka produktivitas nasional yang cukup rendah. Peningkatan produktivitas dapat dilakukan dengan menyediakan unsur hara secara tepat melalui analisis tanah dan irigasi tetes. Penelitian bertujuan mendapatkan dosis optimum rekomendasi pemupukan tanaman terung berdasarkan uji analisis tanah Mehlich 1. Penelitian dilakukan di lahan terbuka Kebun Percobaan Cikarawang, Institut Pertanian Bogor selama bulan Juni sampai November 2022. Penelitian ini menggunakan rancangan kelompok lengkap teracak (RKLT) dengan satu faktor yaitu perlakuan 5 dosis pemupukan (0% X, 50% X, 100% X, 150% X, dan 200% X di mana X merupakan rekomendasi dosis pupuk Ferads) dengan 5 ulangan. Pemberian pupuk N, P, dan K melalui irigasi tetes mampu meningkatkan tinggi tanaman, diameter batang, jumlah buah, dan bobot buah, serta mempercepat waktu antesis, waktu buah masak, dan growing heat summation. Dosis optimum pemupukan untuk tanaman terung varietas Yuvita F1 di tanah latosol tercapai pada taraf 137,74% dosis pada taraf P-tersedia sangat rendah (Mehlich 1) dan K-tersedia sedang (Mehlich 1). Dosis pupuk rekomendasi Ferads 100% dapat digunakan karena peningkatan dosis pupuk optimasi tidak meningkatkan produksi secara signifikan., Eggplant is widely cultivated in Indonesia but still has a relatively low national productivity. Productivity can be increased by providing the right nutrients amount through soil analysis and drip irrigation. The objective of this study was to find optimum fertilization recommendation dose for eggplant based on Mehlich 1 soil analysis test. The study was conducted on open field at Cikarawang, Experimental Farm, Bogor Agricultural University from June to November 2022. This study used a randomized complete block design (RCBD) with one factor that consisted of 5 doses of fertilization (0% X, 50% X, 100% X, 150% X, and 200% X where X is the recommended fertilizer dose from Ferads) with 5 replications. Application of N, P, and K fertilizers through drip irrigation can increased plant height, stem diameter, number of fruits, and fruit weight, as well as speed up anthesis time, fruit ripening time, and growing heat summation. The optimum dose of fertilizer for eggplant variety Yuvita F1 on latosol soil was reached at the level of 137.74% from recommended dose at very low available P (Mehlich 1) and medium available K (Mehlich 1). 100% Ferads fertilizer recommendation dose can be used because increased fertilizer optimum dose does not significantly produce higher yield.
Keyword: dosis optimum, growing heat summation, Mehlich 1, optimum rate

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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