Judul: Formulation and Aplication of Slow Release Fertilizer to Support the Initial Phase of Pineapple Plant in PT Great Giant Pineapple
Abstrak: Peningkatan hasil panen pertanian sangat bergantung pada ketersedian hara nitrogen. Hara nitrogen yang sangat umum digunakan yaitu pupuk Urea. Akan tetapi, urea memiliki sifat yang sangat mudah terdekomposisi akibatnya pemupukan menjadi tidak efisien dan memiliki dampak yang buruk terhadap lingkungan. Upaya untuk mengatasi hal tersebut adalah dengan cara merancang pupuk nitrogen yang tidak mudah tercuci. Penelitian ini disusun menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) dengan lima perlakuan dan Setiap perlakuan diulang dalam empat ulangan yaitu perlakuan B0 (Pemupukan standar PT. GGP), B1 (Pupuk standar 6 bulan GGP + 40% fly ash + 20% kompos + polimer spray), B2 (Pupuk standar 6 bulan GGP + 20% fly ash + 40% kompos + polimer spray), B3 (Pupuk standar 6 bulan GGP + 40% fly ash + 20% kompos + campuran polimer + polimer spray), B4 (Pupuk standar 6 bulan GGP + 20% fly ash + 40% kompos + campuran polimer + polimer spray). Penambahan polimer dan fly ash mengurangi ketercucian hara nitrogen pada perlakuan B1, B3 dan B4., Increasing agricultural yields is highly dependent on the availability of nitrogen nutrients. The most commonly used nitrogen nutrient is urea fertilizer. However, urea is very easily decomposed as a result of fertilization being inefficient and even has a bad impact on the environment.The strategies that can be used to overcome this are by designing nitrogen fertilizers that are not easily washed (slow release fertilizer). This study was structured using a Completely Randomized Block Design (RKLT) with five treatments and each treatment was repeated in four replications, namely treatment B0 (standard fertilization PT. GGP), B1 (standard fertilizer for 6 months GGP + 40% fly ash + 20% compost + polymer spray), B2 (Standard fertilizer for 6 months GGP + 20% fly ash + 40% compost + polymer spray), B3 (Standard fertilizer for 6 months GGP + 40% fly ash + 20% compost + polymer mixture + polymer spray), B4 ( Standard fertilizer for 6 months GGP + 20% fly ash + 40% compost + polymer mixture + polymer spray). The addition of polymer and fly ash reduced nitrogen nutrient leaching in treatments B1, B3 and B4.
Keyword: Fly Ash, Nitrogen, Pineapple, Polymer

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: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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