Judul: Mycorrhizal Application on Vegetative Growth  of Pineapple (Ananas comosus L.)
Abstrak: Nanas merupakan salah satu komoditas ekspor andalan Indonesia yang tumbuh baik di tanah masam. Tingginya penggunaan pupuk anorganik dalam budidaya nanas mengakibatkan degradasi lingkungan. Kerusakan lingkungan dapat dikurangi dengan menggunakan pupuk organik. Mikoriza merupakan agen hayati yang dapat meningkatkan ketersediaan unsur hara P dan K di dalam tanah. Penelitian ini bertujuan mengetahui efektivitas pupuk hayati mikoriza dan efeknya pada pertumbuhan vegetatif tanaman nanas. Penelitian menggunakan rancangan acak lengkap dengan sembilan taraf perlakuan terdiri dari P0 (Kontrol), P1 (NPK 100% - standar PT. GGP), P2 (Provibio 100% + NPK 100%), P3 (Provibio 100% + NPK 50%), P4 (Mikoriza 100% + NPK 100%), P5 (Mikoriza 100% + NPK 50%), P6 (Provibio 100% + Mikoriza 100% + NPK 50%), P7 (Provibio 75% + Mikoriza 75% + NPK 50%), dan P8 (Provibio 50% + Mikoriza 50% + NPK 50%). Bibit yang digunakan dalam penanaman adalah bagian crown. Polybag berisi 20 kg campuran tanah dan kompos dengan rasio 9:1 digunakan untuk menanam bibit nanas pada semua perlakuan. Dosis pupuk yang digunakan pada dosis 100% adalah NPK dalam bentuk ZA 0,5 g, DAP 2 g, KCl 2 g, mikoriza 5 g, dan Provibio 10 ml / 1 liter air per polybag. Setiap perlakuan memiliki 3 perulangan dan 5 sub anakan. Lokasi penelitian berada di Terbanggi Besar, Kabupaten Lampung Tengah, Provinsi Lampung. Parameter yang diamati adalah sifat kimia tanah, tinggi tanaman, jumlah daun, biomasa, kolonisasi mikoriza, jumlah spora mikoriza, dan kesehatan akar selama 4 bulan pada awal masa pertumbuhan vegetatif tanaman nanas. Analisis data dilakukan dengan metode ANOVA dan Uji Lanjut DMRT. Sifat kimia tanah seperti %C-organik, %N dan unsur hara tersedia meningkat setelah diberikan perlakuan mikoriza. P8 memiliki hasil pertumbuhan vegetatif terbaik secara keseluruhan dengan tinggi tanaman, jumlah daun, dan bobot basah tidak berbeda nyata dengan P1 (NPK 100% - standar PT. GGP) dengan input pupuk anorganik lebih sedikit. P4 (Mikoriza 100% + NPK 100%) dipilih sebagai perlakuan mikoriza dengan kolonisasi mikoriza terbaik karena mendapatkan persentase infeksi akar paling tinggi pada 41,67%, Pineapple is one of Indonesia's main export commodities, and it grows well in acidic soil. The high use of inorganic fertilizers causes environmental degradation. Environmental damage caused by inorganic fertilizers can be reduced by using organic fertilizers. Mycorrhiza is a biological agent that can increase the availability of P and K nutrients in soil. This study aimed to determine the effectiveness of mycorrhizal biofertilizers and their effects on the vegetative growth of pineapple plants. The study used a completely randomized design with nine treatment levels: P0 (Control), P1 (NPK 100% - PT GGP’s standard), P2 (Provibio 100% + NPK 100%), P3 (Provibio 100% + NPK 50%), P4 (Mycorrhiza 100% + NPK 100%), P5 (Mycorrhiza 100% + NPK 50%), P6 (Provibio 100% + Mycorrhiza 100% + NPK 50%), P7 (Provibio 75% + Mycorrhiza 75% + NPK 50%), and P8 (Provibio 50% + Mycorrhiza 50% + NPK 50%). Seedlings used are derived from crown’s part of pineapple. polybags containing 20 kg of soil and compost mixture with a ratio of 9:1 were used to plant the pineapple seedlings in all treatments. The ammount of fertilizer used at 100%
Keyword: Infeksi akar, jumlah spora, kolonisasi mikoriza, tanah masam, acidic soil, mycorrhiza colonization, root infection, spore count

Judul: Improvement of Soil Chemical Properties and Pineapple Plant Growth by Ultilizing Bromelain Waste Fiber and Chopped Bamboo
Abstrak: Permasalahan yang dihadapi oleh PT Great Giant Pineapple pada lahan 88C2 dalam budidaya nanas adalah terjadinya pemadatan tanah (soil compaction) dan rendahnya sifat kimia tanah. Limbah ekstraksi bromelain dan cacahan bambu merupakan bahan organik yang mengandung lignin tinggi sehingga diharapkan akan mempunyai residence time yang lebih panjang. Bahan ini diharapkan dapat memberikan pengaruh terhadap kimia tanah di lapangan sehingga dapat meningkatkan pertumbuhan akar nanas yang selanjutnya dapat meningkatkan produksi nanas. Penelitian ini merupakan percobaan faktorial dua faktor (petak utama) yang ditempatkan dalam rancangan petak terpisah (split plot). Faktor pertama jenis bahan organik organik terdiri dari dua taraf: limbah ekstraksi ekstraksi bromelain dan bambu cacah, merupakan petak utama, faktor kedua dosis bahan organik terdiri dari lima taraf: 0, 20, 40, 60, dan 80 ton ha-1 dan merupakan anak petak. Data diolah dengan menggunakan aplikasi minitab dan parameter yang berpengaruh nyata diolah lebih lanjut dengan Duncan Multiple Range Test (DMRT.) Parameter yang diamati adalah sifat kimia tanah, kadar hara tanaman, dan pertumbuhan vegetatif tanaman. Hasil percobaan menunjukkan bahwa kondisi kesuburan tanah awal rendah. Setelah aplikasi, bahan organik berpengaruh nyata terhadap pH H2O, C-Organik, Fe tersedia, Zn tersedia, Al-dd dan KTK, sedangkan dosis bahan organik berpengaruh nyata terhadap P tersedia. Bahan organik berpengaruh nyata terhadap kadar hara P, namun tingkat kecukupan hara N dan Ca masih rendah. Jenis bahan organik berpengaruh nyata terhadap lebar daun dan indeks tanaman. Dosis bahan organik berpengaruh nyata terhadap lebar daun dan indeks tanaman., The problem faced by PT Great Giant Pineapple's in 88C2 land in pineapple cultivation is soil compaction and low soil chemical properties. Bromelain extraction waste and chopped bamboo are organic materials that contain high lignin so they are expected to have a longer residence time. This material is expected to have an influence on improving the chemical properties of the soil in the field so that it can increase the growth of pineapple root which can further increase pineapple production. This study is a two-factor factorial experiment (main plot) placed in a split plot design. The first factor of the type of organic organic matter consists of two levels: bromelain extraction waste fiber and chopped bamboo, is the main plot, the second factor is the dose of organic matter consists of five levels: 0, 20, 40, 60, and 80 tons of ha-1 and is a child plot. The data was processed with variance analysis and the parameters of real effect were further processed with the Duncan Multiple Range Test (DMRT.) The observed parameters are the chemical properties of the soil, the nutrient content of plants, and the vegetative growth of plants. The results of the experiment showed that the conditions of early soil fertility were low. After application, organic matter has a marked effect on pH H2O, C-Organic, Fe available, Zn available, exchangeable Al and KTK, while the dose of organic matter has a noticeable effect on P available. Organic matter has a significant effect on P nutrient levels, but the level of adequacy of N and Ca nutrients is still low. This type of organic matter has a noticeable effect on the width of the
Keyword: Pineapple, Bromelain, Bamboo

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.
Keyword: