Judul: The Influence of Compost Enriched with FABA on Soil Chemical Properties and Pineapple Growth at 6 months after planting
Abstrak: PT. Great Giant Pineapple (GGP) merupakan perkebunan nanas terbesar ketiga di dunia yang berlokasi di Lampung Tengah dan telah melakukan budidaya nanas secara monokultur sejak 1980. Budidaya nanas secara monokultur mengakibatkan penurunan kualitas tanah, sehingga diperlukan penambahan pembenah tanah untuk memperbaiki kualitas tanah. Usaha perbaikan tanah yang telah dilakukan PT. GGP masih belum cukup karena bahan organik yang diberikan mengalami penurunan cepat akibat iklim tropis Indonesia, sehingga diperlukan tambahan pembenah tanah lain. Penelitian ini bertujuan mengamati pengaruh aplikasi kompos diperkaya fly ash dan bottom ash (FABA) sebagai alternatif pembenah tanah yang dapat memperbaiki kualitas tanah. FABA adalah limbah hasil pembakaran batubara pada pembangkit listrik tenaga uap (PLTU). FABA dapat membantu memperbaiki kualitas tanah karena mengandung unsur hara makro (K, Na, Ca, Mg) dan mikro (Fe, Cu, Zn, Mn). Penelitian dilakukan dengan perlakuan bahan pembenah tanah kompos, kompos+FABA dengan dosis 50 ton/ha diberikan secara tebar dan 25 ton/ha, 15 ton/ha, dan 5 ton/ha diberikan secara palir untuk mengetahui pengaruh perlakuan terhadap sifat kimia tanah dan pertumbuhan tanaman pada 6 bulan setelah tanam (BST). Parameter karakteristik kimia tanah yang diamati meliputi pH, kejenuhan Al, C-organik, N-total, P, basa-basa dapat ditukar, KTK, dan kejenuhan basa. Aplikasi kompos diperkaya FABA dengan dosis 15 ton/ha secara palir menunjukkan hasil yang berpengaruh nyata dan meningkatkan sifat kimia tanah yaitu C-organik, N-total, P-tersedia, K-dd, Ca-dd, Mg-dd, Na-dd, KTK, dan kejenuhan basa, serta menurunkan kejenuhan Al. Aplikasi kompos diperkaya FABA dengan dosis 50 ton/ha secara tebar menunjukkan hasil yang berpengaruh nyata dan meningkatkan pertumbuhan tanaman yaitu panjang daun-D, lebar daun-D, indeks daun-D, berat batang, dan jumlah daun., PT. Great Giant Pineapple (GGP) is the world's third-largest pineapple plantation located in Central Lampung, Indonesia, which has been practicing pineapple cultivation through monoculture since 1980. Monoculture pineapple cultivation has led to a decline in soil quality, necessitating the addition of soil amendments to improve its quality. Despite the efforts made by PT. GGP to enhance the soil, the organic materials provided have rapidly deteriorated due to Indonesia's tropical climate, thus requiring additional soil amendments. This research aims to observe the effects of applying compost enriched with fly ash and bottom ash (FABA) as an alternative soil amendment to improve soil quality. FABA is a by-product of coal combustion from steam power plants (PLTU). FABA can help improve soil quality because it contains macro nutrients (K, Na, Ca, Mg) and micro nutrients (Fe, Cu, Zn, Mn). The study involved treating the soil with compost, compost+FABA at a rate of 50 tons/ha applied broadcast and 25 tons/ha, 15 tons/ha, and 5 tons/ha applied in bands, to determine the impact of the treatments on the soil's chemical properties and plant growth at 6 months after planting (MAP). The observed soil chemical characteristics included pH, aluminum saturation, organic carbon, total nitrogen, phosphorus, exchangeable bases, cation exchange capacity (CEC), and base saturation. The application of FABA-enriched compost at a rate of 15 tons/ha using the palir method significantly improved soil chemical properties, including organic C, total N, available P, exchangeable K, Ca, Mg, and Na, cation exchange capacity (CEC), and base saturation, while reducing Al saturation. Additionally,
Keyword: Pemanfaatan Limbah FABA, Soil quality, Compost, Soil amendment

Judul: Improvement of Soil Quality at Pineapple Plantation PT. Great Giant Pineapple uses FABA and Lignite Enriched Compost
Abstrak: Penurunan kualitas tanah berupa penurunan kesuburan tanah telah terjadi di PT. Great Giant Pineapple (GGP) akibat budidaya nanas secara monokultur sejak 1980-an. Kualitas tanah bisa diperbaiki melalui bahan pembenah tanah. Aplikasi kompos sebagai pembenah tanah telah dilakukan oleh PT. GGP, namun pengaruhnya belum optimal, sehingga diperlukan penambahan pembenah tanah lain. Contoh alternatif pembenah tanah yang lain adalah limbah abu batubara (fly ash dan bottom ash atau FABA) dan batubara muda (lignit). Penelitian ini bertujuan memperbaiki kualitas tanah secara kimia di perkebunan nanas PT. GGP melalui pemberian kompos diperkaya FABA dan lignit. Penelitian dilakukan secara eksperimental di lahan percobaan Research and Development PT. GGP Blok 86 A menggunakan Rancangan Petak Terbagi. Perlakuan terdiri atas bahan pembenah tanah kompos, kompos+FABA, dan kompos+FABA+lignit yang diaplikasikan secara tebar dan palir. Hasil penelitian menunjukkan bahwa pengkayaan kompos dengan FABA dan lignit meningkatkan beberapa sifat kimia pembenah tanah diantaranya pH, C-organik, P-total, Ca, Mg, K, Mn, dan Cu. Aplikasi kompos+FABA+lignit secara palir lebih baik dalam memperbaiki beberapa sifat kimia tanah di lahan PT. GGP, diantaranya menurunkan kemasaman tanah serta meningkatkan C-organik, N-total, P-total, P-tersedia, K-dd, Ca-dd, Mg-dd, Na-dd, KTK, dan kejenuhan basa. Perlakuan tersebut belum memperlihatkan pengaruh yang lebih baik dalam meningkatkan N-total, P-tersedia dan K-dd dibandingkan dengan kompos murni., Degradation in soil quality, such as a decrease in soil fertility has occurred at PT. Great Giant Pineapple (GGP) due to monoculture pineapple cultivation since the 1980s. Soil quality can be improved by the application of soil ameliorants. The application of compost as a soil ameliorant has been carried out by PT. GGP, but the effect is not optimal, so it is necessary to add other soil ameliorants. Other soil ameliorant alternatives are coal ash waste (fly ash and bottom ash or FABA) and lignite. This study aims to improve soil quality, especially its chemical properties in the pineapple plantation of PT. GGP with the application of FABA and lignite enriched compost. The research was conducted experimentally at the Research and Development experimental area of PT. GGP Block 86 A uses a Split Plot Design. The treatments consisted of compost, compost+FABA, and compost+FABA+ lignite which is a soil ameliorant material that is applied by spreading it and given in the planting row. The results showed that the enrichment of compost with FABA and lignite increased several chemical properties of the soil ameliorants, including pH, C-organic, P-total, Ca, Mg, K, Mn, and Cu. The application of compost+ FABA+lignite, especially in planting rows, was better in improving some soil chemical properties in PT. GGP, among others, reduces soil acidity and increases C-organic, N-total, P-total, P-available, K-dd, Ca-dd, Mg-dd, Na-dd, CEC, and base saturation. This treatment has not shown a better effect in increasing the total N, P-available, and K-dd compared to compost.
Keyword: compost, FABA, lignite, soil ameliorant

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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