Judul: Amelioration of Compost and Coal Ash on an Ultisol of Pineapple Plantation: Temporal Dynamics of Soil Chemical Properties
Abstrak: Kendala utama sifat kimia Ultisols untuk pertanian meliputi rendahnya pH, bahan organik, KTK, dan ketersediaan hara. Penelitian ini bertujuan mengevaluasi dinamika temporal sifat kimia tanah pada 0, 2, 6, 9, dan 10 bulan setelah ameliorasi (BSA) kompos dan abu batu bara (FABA) pada Ultisol di lahan perkebunan nanas. Penelitian terdiri dari percobaan lapang dan percobaan perkolasi di rumah kaca dengan RAL, keduanya terdiri dari 6 taraf perlakuan yaitu kontrol, kompos 50 ton/ha (KT 50), Kompos+FABA 50 ton/ha (KFT 50), KFA 25, KFA 15, dan KFA 5, T= tebar dan A=alur. Selain amelioran ini, tanah juga dipupuk lengkap. Analisis dengan metode rutin dilakukan terhadap sifat-sifat kimia tanah lapisan 0-20 cm pada 0 dan 2 BSA dari percobaan lapang, pada 9 dan 10 BSA dari percobaan perkolasi, dan pada 6 BSA berdasarkan ekstrapolasi. Perlakuan berpengaruh sangat nyata. Secara umum, sifat-sifat kimia tanah terbaik diperoleh pada perlakuan KFA 25. Kadar hara semakin turun dengan waktu akibat proses pencucian. Pada perlakuan terbaik 10 BSA, kadar C-organik, N-total dan KTK tanah lebih tinggi dari kadar awal meskipun masih tergolong rendah, sedangkan P-tersedia juga lebih tinggi dari kadar awal dan tetap tergolong sangat tinggi. Namun, kadar K-dd, Cadd, dan Mg-dd lebih rendah dari kadar awal dan tetap tergolong sangat rendah. Untuk mempertahankan produktivitas tanaman, maka disarankan untuk memberikan pupuk N dan K serta ameliorasi kompos dan FABA pada 10 BSA., The main chemical constraints of Ultisols for agriculture include low soil pH, organic matter, CEC, and nutrients availability. This study aims to evaluate temporal dynamics of soil chemical properties at 0, 2, 6, 9, and 10 months after amelioration (MAA) of compost and coal ash (FABA) on an Ultisol of pineapple plantation. The study consisted of field and greenhouse percolation experiments, both with CRD consisting of control, 50 ton/ha compost (CB 50), 50 tons/ha compost+FABA (CFB 50), CFR 25, CFR 15, and CFR 5 treatment levels, where B = broadcast and R = row application. Besides, the soil was completely fertilized. Chemical analyses were done using routine methods on soil samples of 0-20 cm layer at 0 and 2, 9 and 10, and 6 MAA, respectively from the field experiment, from the percolation experiment, and based on extrapolation. The treatment’s effects were very significant. In general, the best results were obtained at CFR 25 treatment level. The nutrient status decreased with time due to leaching processes. From the best treatment at 10 MAA, compared to the corresponding initial status, soil organic-C, total-N, and CEC were higher than, although still classified as low, whilst P-availability was also higher than, but still classified as very high. However, the soil exchangeable-K, -Ca, and -Mg were lower than the initial levels and still classified as very low. To maintain plant productivity, it is suggested to apply supplementary N and K fertilizers and compost and FABA ameliorants at 10 MMA.
Keyword: ameliorant, broadcast, leaching, percolation, row

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: 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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