Judul: The Effect of Chemical Fertilizer Dosage and Type of Biofertilizer on the Growth and Production of Soybean (Glycine max L.)
Abstrak: Kedelai (Glycine max L.) adalah komoditas pangan yang banyak dikonsumsi oleh masyarakat Indonesia. Tingginya kebutuhan kedelai dalam negeri membuat usaha untuk meningkatkan produksi sangat dibutuhkan. Salah satu caranya dengan meningkatkan kesuburan tanah melalui pemupukan. Penelitian ini bertujuan mengetahui pengaruh dosis pupuk kimia dan penambahan pupuk hayati terhadap pertumbuhan dan produksi tanaman kedelai. Penelitian dilakukan di Kebun Percobaan IPB Sawah Baru dari bulan November 2023 hingga Maret 2024. Percobaan menggunakan rancangan Split-Plot RKLT dengan dua faktor yaitu faktor pupuk kimia sebagai petak utama dengan dua taraf, yaitu 50% (K1) dan 100% (K2) dosis dan faktor pupuk hayati sebagai anak petak dengan 5 taraf, yaitu tidak diberi pupuk hayati (H0), pupuk hayati jenis 1 (H1), pupuk hayati jenis 2 (H2), pupuk hayati jenis 3 (H3) dan pupuk hayati jenis 4 (H4). Perlakuan 100% dosis pupuk kimia dapat meningkatkan jumlah daun 8 MST, jumlah cabang 8-10 MST, nilai kehijauan daun, nilai indeks luas daun, bobot brangkasan, jumlah polong dan biji per tanaman, bobot biji per tanaman dan bobot 100 butir. Sementara pupuk hayati jenis 4 dapat meningkatkan jumlah cabang 6-8 MST, jumlah polong dan biji per tanaman, serta indeks luas daun tetapi tidak berbeda nyata dengan pupuk hayati jenis 1,2,3, dan kontrol., Soybeans (Glycine max L.) are a commodity that is widely consumed by Indonesian people. The high level of demand for soybeans in Indonesia make efforts to increase production is necessary. One of the ways to increase soil fertility through fertilizing with biological fertilizer. This research aims to determine the effect of chemical fertilizer doses and the addition of biological fertilizer on the growth and production of soybean plants. The research was conducted at the IPB Sawah Baru Experimental station from November 2023 to March 2024. The experiment used a Split-Plot RCBD design with two factors, namely the chemical fertilizer factor as the main plot with two levels, namely 50% (K1) and 100% (K2) of the dose. optimum and biofertilizer factors as sub-plots with 5 levels, namely no biofertilizer (H0), type 1 biofertilizer (H1), type 2 biofertilizer (H2), type 3 biofertilizer (H3) and type 4 biofertilizer (H4). Treatment 100% dose with chemical fertilizer can increase the number of leaves 8 WAP, number of branches 8-10 WAP, leaf greenness value, leaf area index, dry weight of stover, number of pods per plant, number of seeds per plant, weight of seeds per plant, number of 100 grains. Type 4 biological fertilizer can increase the number of branches 6-10 WAP, number of pods per plant, leaf area index, and number of seeds per soybean plant but is not significantly different from the type 1,2,3 biofertilizer and control.
Keyword: Pupuk hayati, Produksi, detap 1

Judul: The Effect of Doses of Phosphorus and Potassium Fertilizers on the Growth and Production of Soybean (Glycine max (L.) Merrill)
Abstrak: Kedelai merupakan salah satu komoditas prioritas yang diupayakan untuk ditingkatkan produksinya guna mengurangi impor. Upaya peningkatan produksi nasional kedelai di antaranya perbaikan teknik budi daya melalui pengaturan pupuk. Pupuk fosfor (P) dan kalium (K) menjadi salah satu pupuk dasar yang dibutuhkan untuk budi daya kedelai. Penelitian ini bertujuan mendapatkan informasi mengenai pengaruh dosis pupuk P dan K terhadap pertumbuhan dan produksi kedelai. Penelitian dilakukan di Kebun Percobaan IPB Sawah Baru dari bulan September hingga Desember 2021. Percobaan menggunakan rancangan kelompok lengkap teracak (RKLT) dengan dua faktor percobaan, yakni dosis pupuk P (0, 50, 100, dan 150 kg SP-36 ha-1) dan dosis pupuk K (0, 100, dan 150 kg KCl ha-1). Varietas yang digunakan adalah Anjasmoro. Hasil penelitian menunjukkan pemberian pupuk P mempercepat umur panen serta menaikkan indeks luas daun, nilai kehijauan daun fase R1, bobot kering tajuk, laju pertumbuhan tanaman fase R5−R8, bobot biji per tanaman, bobot ubinan, dan potensi hasil kedelai. Dosis 150 kg SP-36 ha-1 menghasilkan bobot biji per tanaman, bobot ubinan, dan potensi hasil tertinggi dibanding dosis lainnya. Hasil panen perlakuan pupuk P 100 kg SP-36 ha-1 dan 150 kg SP-36 ha-1 melampaui potensi hasil varietas. Pemupukan K memperpanjang fase pengisian polong (R5) dan meningkatkan tinggi tanamana pada 9 MST, bobot kering tajuk, bobot biji per tanaman, bobot 100 butir, bobot ubinan, dan potensi hasil kedelai. Dosis 150 kg KCl ha-1 menghasilkan komponen produksi kedelai tertinggi dibanding dosis lainnya., Soybean is one of the priority commodity which production is being increased in order to reduce imports. Efforts to increase national soybean production by improving cultivation techniques through fertilizer regulation. Phosphorus (P) and potassium (K) fertilizers are one of the basic fertilizers needed for soybean cultivation. This research aims to obtain information on the effect of doses of P and K fertilizers on soybean growth and production. The research was conducted at Sawah Baru Experimental Field and Post-harvest Laboratory of IPB University from September to December 2021. This research used a randomized complete block design (RCBD) with two experimental factors, the dose of P fertilizer (0, 50, 100, and 150 kg SP-36 ha-1) and the dose of K fertilizer (0, 100, and 150 kg KCl ha-1). Variety used was Anjasmoro. The results showed that the application of P fertilizer accelerated harvest age and increased leaf area index, leaf greenness in R1 phase, culm and leaf dry weight, rate of plant growth in R5−R8 phase, weight of seeds per plant, tile weight, and soybean yield potential. A dose of 150 kg SP-36 ha-1 produced the highest weight of seeds per plant, tile weight, and yield potential compared to other doses. The yields of fertilizer treatments of P 100 kg SP-36 ha-1 and 150 kg SP-36 ha-1 exceeded the yield potential of the variety. K fertilization extended age of pods filling (R5) and increased plant height at 9 WAP, culm and leaf dry weight, weight of seeds per plant, weight of 100 seeds, tile weight, and soybean yield potential. The dose of 150 kg KCl ha-1 resulted in the highest soybean production component compared to other doses.
Keyword: age of pods filling, culm and leaf dry weight, harvest age, seed weight, yield potential

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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