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: 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: A Continuous Vaccination Strategy in the SVIR Epidemic Model
Abstrak: Vaccination is conducted to minimize the spread of a disease. The vaccination is usually done several times within a fixed time interval. In the SVIR model, it is assumed that individuals do not get immediate immunity following a vaccination program. So according to process of vaccination on SVIR model, there are two strategies, i.e. the continuous vaccination strategy (CVS) and the pulse vaccination strategy (PVS). In this study, only the CVS strategy in epidemic model SVIR is considered. Results of the study indicate that dynamics of the CVS system depends on the basic reproductive number. If the basic reproductive number is less than one, then the disease-free fixed point is asymptotically stable. It means that the disease will eventually disappear from the population. Conversely, if the basic reproductive number is greater than one, then the endemic fixed point is asymptotically stable, which means that the disease will remain exist in the population. Simulation result shows that the vaccination would minimize the spread of disease by reducing the basic reproductive number. If the time for the vaccinated recipients to obtain the immunity, as well as a possibility of vaccinated recipients to be infected are neglected, then the disease will be eradicated. This condition is called an over-evaluating effect of vaccination.
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