Judul: The Effectiveness of Vermicompost Fertilizer and  Arbuscular Mycorrhizal Fungi in Increasing the Productivity of Alfalfa Plants (Medicago sativa L.)
Abstrak: Penelitian ini bertujuan menguji pengaruh pemberian pupuk vermikompos dan fungi mikoriza arbuskula (FMA) terhadap produktivitas tanaman Alfalfa (Medicago sativa L.). Penelitian ini menggunakan rancangan acak lengkap (RAL) dengan 220 sampel yang dibagi menjadi 11 perlakuan dan 20 ulangan. Perlakuan terdiri dari K0 = Media tanah tanpa perlakuan; K100 = K0 + 100% NPK; K50 = K0+ 50% NPK; AV1 = K50 + 100 g vermikompos; AV2 = K50 + 200 g vermikompos; AF1 = K50 + 10 g FMA; AF2 = K50 + 20 g FMA; AVIF1 = K50 + 100 g vermikompos + 10 g FMA; AV1F2 = K50 + 100 g vermikompos + 20 g FMA; AV2F1 = K50 + 200 g vermikompos + 10 g FMA; AV2F2 = K50 + 200 g vermikompos + 20 g FMA. Parameter yang diukur adalah persentase kolonisasi akar, tinggi tanaman, jumlah cabang, jumlah daun, diameter batang, panjang akar, berat segar akar, berat segar tajuk, dan berat kering tajuk. Hasil penelitian menunjukkan bahwa perlakuan kombinasi vermikompos dan FMA sangat berpengaruh nyata (P<0,01) dalam meningkatkan seluruh parameter yang diamati. Simpulan dari penelitian ini adalah kombinasi pupuk vermikompos 200 g dan FMA 10 g efektif meningkatkan produktivitas tanaman Alfalfa., TThis study aims to examine the effect of vermicomposting and arbuscular mycorrhizal fungi (AMF) on the productivity of Alfalfa plants (Medicago sativa L.). This study use a randomized complete design with 220 samples divided into 11 treatments and 20 repeats. The treatment consists of K0 = untreated media; K100 = K0 + 100% NPK; K50 = K0 + 50% NPK; AV1 = K50 + 100 g vermicompost; AV2 = K50 + 200 g vermicompost; AF1 = K50 + 10 g AMF; AF2 = K50 + 20 g AMF; AVIF1 = K50 + 100 g vermicompost + 10 g AMF; AV1F2 = K50 + 100 g vermicompost + 20 g AMF; AV2F1 = K50 + 200 g vermicompost + 10 g AMF; AV2F2 = K50 + 200 g vermicompost + 20 g AMF. The parameters measured are percentage of root infection, plant height, number of branches, number of leaves, stem diameter, root length, fresh weight of roots, fresh weight of leaves and steam, and dry weight of leave and steam The results showed that the combination treatment of vermicompost and FMA had a significant effect (P<0.01) in improving all observed parameters. The conclusion of this study is that the combination of vermicompost fertilizer 200 g and FMA 10 g effectively increases the productivity of Alfalfa plants.
Keyword: alfalfa, arbuscular mycorrhizal fungi (AMF), productivity, vermicompost

Judul: Optimization of Inoculation Time and FMA Level on Alfalfa Plants (Medicago sativa L.)
Abstrak: Alfalfa merupakan tanaman subtropis yang sulit beradaptasi di daerah tropis. Penelitian ini bertujuan mengevaluasi efektivitas pemberian fungi mikoriza arbuskula (FMA) berdasarkan waktu inokulasi dan level terhadap pertumbuhan tanaman alfalfa (Medicago sativa L.). Rancangan percobaan berupa Rancangan Acak Lengkap (RAL) faktorial 2 x 6 dengan 20 ulangan. Faktor I yaitu waktu inokulasi, meliputi persemaian dan pembibitan. Faktor F yaitu level FMA, meliputi kontrol positif, 0 g FMA (A50F0), 5 g FMA (A50F5), 10 g FMA (A50F10), 15 g FMA (A50F15), dan 20 g FMA (A50F20). Hasil penelitian menunjukkan waktu inokulasi dan level FMA berpengaruh nyata (P<0,05) terhadap morfologi tanaman. Tanaman dengan inokulasi FMA memberikan respon yang baik terhadap kolonisasi FMA, berat segar dan kering tanaman alfalfa. Kesimpulan bahwa inokulasi FMA efektif meningkatkan produktivitas tanaman alfalfa (kolonisasi akar, tinggi, jumlah daun, jumlah tangkai daun, jumlah cabang, diameter batang, berat segar dan kering, serta warna daun) dibanding kontrol dan tanpa FMA. Inokulasi FMA pada periode persemaian cenderung lebih efektif. Inokulasi FMA level 20 g pada periode persemaian memberikan hasil yang baik secara konsisten., Alfalfa is a subtropical plant that is difficult to adapt to the tropics. This study aims to evaluate the effectiveness of arbuscular mycorrhizal fungi (FMA) application based on inoculation time and level on alfalfa plant growth (Medicago sativa L.). The experimental design is a 2 x 6 factorial completely randomized design (CRD) with 20 replications. Factor I is the time of inoculation, including nursery (I1) and seedling (I2). Factor F is FMA level, including positive control (A100F0), 0 g FMA (A50F0), 5 g FMA (A50F5), 10 g FMA (A50F10), 15 g FMA (A50F15), and 20 g FMA (A50F20). The results showed that inoculation time and FMA level had a significant effect (P<0.05) on plant morphology. Plants with FMA inoculation gave a good response to FMA colonization, fresh and dry weight of alfalfa plants. It is concluded that FMA inoculation effectively increases alfalfa plant productivity (root colonization, height, number of leaves, number of petioles, number of branches, stem diameter, fresh and dry weight, and leaf color) compared to control and without FMA. FMA inoculation in the nursery period tends to be more effective. FMA inoculation level of 20 g in the nursery period gave consistently good results.
Keyword: alfalfa, fungi, inokulasi, mikoriza arbuskula

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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