Judul: Perbaikan Tanah Medis Tanaman Jeruk Dengan Berbagai Bahan Organik Dalam Bentuk Kompos
Abstrak: Penambahan bahan organik berupa kompos dapat memperbaiki sifat-sifat tanah, akan tetapi banyak ditinggalkan penggunaannya padahal perannya sangat besar bagi perbaikan tanah. Selain itu, penggunaan bahan yang tidak ditemukan di lapang pun sering terjadi. Penggunaan bahan organik yang mudah diperoleh setempat (in situ) dipandang efektif sebagai bahan pembuat kompos. Penelitian ini menggunakan lima macam bahan organik in situ, dengan tujuan mengetahui kandungan hara dari kompos yang digunakan, melihat pengaruh penambahan kompos terhadap perubahan sifat-sifat tanah dan pertumbuhan tanaman, dan mencari jenis kompos yang memberikan pengaruh terbaik terhadap pertumbuhan tanaman jeruk. Penelitian ini menganalisis sifat kimia, biologi tanah, dan fisika, dan analisis kadar hara tanaman. Hasil penelitian menunjukkan bahwa kandungan hara kompos tergantung dari jenis bahan asalnya. Pengaruh aplikasi kompos terhadap sifat-sifat tanah media tanaman jeruk sudah mulai terlihat sejak tiga bulan setelah aplikasi, di mana terjadi peningkatan ketersediaan hara di dalam tanah. Kompos juga sangat mempengaruhi populasi cacing di dalam tanah, terlihat dari aplikasi kompos jerami padi populasi cacing mencapai 906 ekor/m2, bahkan aplikasi kompos rumput mencapai 1099 ekor/m2. Terhadap sifat fisik, aplikasi kompos memperbaiki porositas trumbuk, dengan perbandingan komposisi pembentuk tanah menjadi lebih baik. Pertumbuhan tanaman selama enam bulan setelah aplikasi kompos sedikit dipengaruhi oleh penambahan kompos yang dapat terlihat dari masih kurangnya perubahan dalam kadar hara tanaman jeruk, namun dari jumlah buah sudah terlihat bahwa aplikasi kompos kotoran sapi dan kompos batang pisang jelas meningkatkan produksi buah.
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Judul: Perbaikan Tanah Media Tanaman Jeruk dengan Berbagai Bahan
Abstrak: Addition of compost can improve the properties of soil, but it is rarely used although it has many benefits to soil. On the other hand, the use of ex situ material has been found in many places. Organic substances that easily available in situ are effective as compost materials. This research used five in situ organic substances with the objectives: to know the nutrient content of compost that have been used, to see the influence of compost addition to soil properties and citrus growth, and to find the compost type that giving the best influence to the growth of citrus crop. This research analyzed the physical, chemical, and biological properties of soil, and analyzed the nutrient content of the crop. The results of this research indicated that the nutrient content of compost depended on its origin. Compost influenced the properties of soil beginning three months after compost application that was showed by the increasing of nutrient availability. Compost also influenced the earthworm population where 906 worms/m2 have been found after six months of application of straw compost, and 1099 worms/m2 after application of grass compost. Compost application influenced physical properties of soil that encourage “the piled soil” (trumbuk) porosity, through improvement the composition of soil. After six month of application, the growth of the citrus plant was slightly influenced by addition of compost, this can be seen from the nutrient content of the plants, but from the amount of citrus fruits were shown clearly that application of cattle dung and banana tree compost could increased the yields.
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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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