Judul: The Effectiveness of Biofertilizer Dosage on the Growth of Pineapple Plants (Ananas Comosus L.Merr) in the Vegetative Phase
Abstrak: Tanaman nanas merupakan komoditas unggulan di Indonesia, produksi tertinggi berada di Provinsi Lampung. Penggunaan pupuk anorganik di Lampung sangat tinggi hal ini disebabkan karena tingkat kesuburan tanah yang rendah. Penggunaan pupuk anorganik dapat memberikan dampak buruk pada kesehatan tanah. Pupuk hayati memiliki kandungan mikroorganisme yang dapat memperbaiki kesuburan serta kesehatan tanah. Penelitian bertujuan mengetahui efektivitas dosis pupuk hayati dengan mengurangi dosis pupuk anorganik dan mengetahui pertumbuhan vegetatif tanaman nanas. Pengambilan tanah dilakukan dengan metode komposit pada sub anakan dengan tiga ulangan. Desain penelitian menggunakan RAL (Rancangan Acak Lengkap) uji lanjut DMRT 5% (software R- Studio), dan uji korelasi (Microsoft Excel 2019) dengan sembilan taraf perlakuan tiga ulangan. Sembilan taraf perlakuan tersebut adalah Sembilan taraf perlakuan tersebut adalah P0 (Pupuk kandang - kontrol), P1 (NPK 100% - standar GGP), P2 (Pupuk hayati Provibio 100% + NPK 100%), P3 (Pupuk hayati Provibio 100% + NPK 50%), P4 (Mikoriza 100% + NPK 100%), P5 (Mikoriza 100% + NPK 50%), P6 (Pupuk hayati Provibio 100% + Mikoriza 100% + NPK 50%), P7 (Pupuk hayati Provibio 75% + Mikoriza 75% + NPK 50%), P8 (Pupuk hayati Provibio 50% + Mikoriza 50% + NPK 50%). Hasil penelitian menunjukkan bahwa pemberian pupuk hayati mempengaruhi peningkatan pH, N-total, c-organik, C/N rasio, dan K- total. Total populasi mikrob terbaik pada perlakuan P5 (Mikoriza 100% + NPK 50%) dan P6 (Provibio 100% + Mikoriza 100% + NPK 50%). Sedangkan pada parameter pertumbuhan tanaman nanas, bobot basah, dan bobot kering tidak memberikan pengaruh nyata pada seluruh parameter. Pada parameter kesehatan akar termasuk dalam kategori agak sehat sampai ke sehat. Nilai korelasi tinggi didapatkan antara pH dengan total mikrob sebesar 0,649. Pemberian pupuk hayati pada penelitian ini memberikan hasil yang positif di beberapa perlakuan. Perlakuan dengan dosis pupuk hayati terbaik yang menyerupai hasil dosis standar pemupukan antara lain P5 (Mikoriza 100% + NPK 50%) dan P8 (Pupuk hayati Provibio 50% + Mikoriza 50% + NPK 50%)., Pineapple is a leading commodity in Indonesia, with the highest production in Lampung Province. The use of inorganic fertilizers in Lampung is very high, mainly due to the low fertility level of the soil. The use of inorganic fertilizers can have a negative impact on soil health. Biofertilizers contain microorganisms that can improve soil fertility and health. The research aimed to determine the effectiveness of fertilizer doses and vegetative growth of pineapple plants. Soil samples were taken using composite methods on three seedlings with three replications. The research design used a Completely Randomized Design (CRD) with ANOVA test, DMRT 5% test (R-Studio software), and correlation test (Microsoft Excel 2019) with nine levels treatment of three. Ninth levels treatment are P0 (Pupuk kandang - kontrol), P1 (NPK 100% - standar GGP), P2 (Pupuk hayati Provibio 100% + NPK 100%), P3 (Pupuk hayati Provibio 100% + NPK 50%), P4 (Mikoriza 100% + NPK 100%), P5 (Mikoriza 100% + NPK 50%), P6 (Pupuk hayati Provibio 100% + Mikoriza 100% + NPK 50%), P7 (Pupuk hayati Provibio 75% + Mikoriza 75% + NPK 50%), P8 (Pupuk hayati Provibio 50% + Mikoriza 50% + NPK 50%). The research results show that the application
Keyword: Soil fertility, Soil health, Microorganisms, PH

Judul: Effect of Composition of Compost, Fly ash, and  Mineral Fertilizer on N Availability of Pineapple (Ananas comosus L. Merr)  Growth
Abstrak: Nitrogen merupakan unsur hara esensial bagi pertumbuhan tanaman. Kehilangan nitrogen dalam tanah disebabkan oleh adanya pencucian, penguapan, dan yang terserap oleh tanaman. Penelitian ini bertujuan mengidentifikasi pengaruh persentase kompos dan fly ash terhadap ketersediaan hara N pada pertumbuhan tanaman nanas, serta mengidentifikasi perbaikan pertumbuhan tanaman nanas dan sistem perakarannya akibat aplikasi SRF dibandingkan dengan pupuk standar baku PT. GGP. Penelitian dilaksanakan di Kebun Reasearch and Development PT Great Giant Pineapple, Kabupaten Lampung Tengah pada bulan Oktober 2021 – Januari 2022. Tanaman yang diamati merupakan tanaman nanas klon GP3. Penelitian ini menggunakan 3 komposisi kompos dan fly ash dalam pupuk mineral yaitu tanpa pemberian kompos dan fly ash, 40% kompos dan 20% fly ash, serta 20% kompos dan 40% fly ash masing-masing 4 ulangan. Hasil penelitian menunjukkan persentase kompos dan fly ash tidak berbeda nyata terhadap ketersediaan N dalam tanah, N tercuci, dan N menguap, serta pertumbuhan daun dan akar., Nitrogen is an essential nutrient for plant growth. Loss of nitrogen in the soil is caused by leaching, evaporation, and being absorbed by plants. This study aims to identify the effect of the percentage of compost and fly ash on the availability of N-nutrients on the growth of pineapple plants, as well as identify the improvement of pineapple plant growth and root system due to SRF application compared to standard standard fertilizers of PT. GGP. The research was carried out at the Research and Development Garden of PT Great Giant Pineapple, Central Lampung Regency in October 2021 – January 2022. The plant to be monitored is a GP3 clone of pineapple. This study uses 3 compositions of compost and fly ash in mineral fertilizers, namely without compost and fly ash, 40% compost and 20% fly ash, as well as 20% compost and 40% fly ash with 4 replications each. The results showed that the percentages of compost and fly ash were not significantly different to the availability of N in the soil, leached N, evaporated N, and root and leaf growth.
Keyword: plant vegetative, slow release fertilizers, waste coal

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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