Judul: The Effect of Providing Compost Enriched with Fly Ash Bottom  Ash on the Soil Biological Properties in Pineapple Plantations
Abstrak: Pemanfaatan pemberian pembenah tanah berupa kompos yang diperkaya fly ash bottom ash (FABA) merupakan salah satu solusi alternatif untuk mempertahankan populasi organisme di dalam tanah. Pemberian kompos diperkaya FABA dapat memperbaiki sifat-sifat tanah. Penelitian ini bertujuan mengukur pengaruh pemberian bahan pembenah tanah dalam hal ini kompos diperkaya FABA terhadap kesuburan biologi tanah, yaitu mikrob tanah, respirasi tanah dan cacing tanah. Dalam penelitian ini, perlakuan pembenah tanah menggunakan kompos, serta kompos+FABA dengan dosis masing masing petak sebanyak 5, 15, 25 ton/ha yang diberikan secara palir (P) dan 50 ton/ha diberikan secara tebar (T). Parameter total mikrob dan respirasi tanah dianalisis menggunakan contoh tanah yang diambil secara komposit. Populasi cacing tanah dilakukan pada setiap petak dan diambil 3 titik pengamatan secara zigzag. Hasil pengamatan total mikrob tanah menghasilkan jumlah total mikrob tanah dan respirasi tanah paling tinggi dijumpai pada perlakuan kompos+FABA 50 ton/ha yang diberikan secara tebar. Pengamatan jumlah cacing tanah dan biomassa cacing tanah paling tinggi terdapat pada perlakuan kompos+FABA 25 ton/ha yang diberikan secara palir. Pemberian pembenah tanah berupa kompos diperkaya FABA mampu meningkatkan mikrob tanah, cacing tanah dan respirasi tanah dibandingkan perlakuan lain seperti kompos dan kontrol.
Keyword: microbial activity, earthworms, soil microbes, row treatment, soil respiration, spread treatme

Judul: The Influence of FABA Enriched Compost Utilization on Soil Chemical Properties at Pineapple Plantation PT. Great Giant Pineapple
Abstrak: Penurunan sifat-sifat kimia tanah di PT. Great Giant Pineapple (GGP) terjadi akibat budidaya monokultur jangka panjang, penggunaan pupuk kimia secara intensif, serta jenis tanah yang didominasi oleh Ultisol. Perbaikan kualitas tanah dapat dilakukan melalui pemberian bahan pembenah tanah. Usaha perbaikan telah dilakukan oleh PT. GGP melalui pengembalian bahan organik sisa panen serta pengaplikasian kompos, namun hasil yang diperoleh belum terlihat nyata sehingga diperlukan kompos yang diperkaya dengan bahan pembenah tanah lain. Pemanfaatan limbah abu batubara atau fly ash-bottom ash (FABA) sebagai bahan pembenah tanah yang dikombinasikan dengan kompos dapat memperbaiki kualitas tanah dengan lebih efektif. Percobaan melalui pemberian kompos+FABA secara tebar dengan dosis 50 ton/ha dan secara palir (jalur tanam) dengan dosis 25 ton/ha, 15 ton/ha, dan 5 ton/ha dilakukan untuk mengetahui pengaruh perlakuan terhadap sifat kimia tanah. Parameter karakteristik kimia tanah yang diamati meliputi pH, kejenuhan Al, C-organik, N-total, P-total, P-tersedia, basa-basa dapat ditukar, KTK, dan kejenuhan basa. Aplikasi kompos diperkaya FABA secara palir dengan dosis 25 ton/ha berpengaruh nyata dan menghasilkan sifat kimia tanah terbaik, diantaranya meningkatkan C-organik, N-total, P-total, P-tersedia, K-dd, Ca-dd, Mg-dd, Na-dd, KTK, dan kejenuhan basa, serta menurunkan kejenuhan Al., Degradation of soil chemical properties at PT. Great Giant Pineapple (GGP) occurs as a result of long-term monoculture cultivation, intensive use of chemical fertilizers, and soil types which are dominated by Ultisols. Soil quality improvement can be done through the application of soil ameliorants. PT. GGP has made efforts to improve soil quality by returning organic matter and applying compost, but the results have not been obvious so compost must be enriched with other soil ameliorants. Utilization of coal ash waste (fly ash-bottom ash or FABA) as soil ameliorant combined with compost can improve soil quality more effectively. Experiments were carried out by applying compost+FABA in broadcast technique at dose of 50 tons/ha and palir technique (planting lines) at doses of 25 tons/ha, 15 tons/ha, and 5 tons/ha to determine the effect of treatment on soil chemical properties. Parameters of soil chemical properties were observed for pH, Al saturation, organic-C, total-N, total-P, available-P, exchangeable bases, CEC, and base saturation. Application of FABA enriched compost in palir technique at dose of 25 tons/ha had a significant effect and produced the best soil chemical properties, including increasing organic-C, total N, total P, available P, exchangeable-K, -Ca, -Mg, and -Na, CEC, base saturation, and also decrease Al saturation.
Keyword: FABA, kompos, pembenah tanah, ameliorant, compost

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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