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: Improvement of Soil Quality at Pineapple Plantation PT. Great Giant Pineapple uses FABA and Lignite Enriched Compost
Abstrak: Penurunan kualitas tanah berupa penurunan kesuburan tanah telah terjadi di PT. Great Giant Pineapple (GGP) akibat budidaya nanas secara monokultur sejak 1980-an. Kualitas tanah bisa diperbaiki melalui bahan pembenah tanah. Aplikasi kompos sebagai pembenah tanah telah dilakukan oleh PT. GGP, namun pengaruhnya belum optimal, sehingga diperlukan penambahan pembenah tanah lain. Contoh alternatif pembenah tanah yang lain adalah limbah abu batubara (fly ash dan bottom ash atau FABA) dan batubara muda (lignit). Penelitian ini bertujuan memperbaiki kualitas tanah secara kimia di perkebunan nanas PT. GGP melalui pemberian kompos diperkaya FABA dan lignit. Penelitian dilakukan secara eksperimental di lahan percobaan Research and Development PT. GGP Blok 86 A menggunakan Rancangan Petak Terbagi. Perlakuan terdiri atas bahan pembenah tanah kompos, kompos+FABA, dan kompos+FABA+lignit yang diaplikasikan secara tebar dan palir. Hasil penelitian menunjukkan bahwa pengkayaan kompos dengan FABA dan lignit meningkatkan beberapa sifat kimia pembenah tanah diantaranya pH, C-organik, P-total, Ca, Mg, K, Mn, dan Cu. Aplikasi kompos+FABA+lignit secara palir lebih baik dalam memperbaiki beberapa sifat kimia tanah di lahan PT. GGP, diantaranya menurunkan kemasaman tanah serta meningkatkan C-organik, N-total, P-total, P-tersedia, K-dd, Ca-dd, Mg-dd, Na-dd, KTK, dan kejenuhan basa. Perlakuan tersebut belum memperlihatkan pengaruh yang lebih baik dalam meningkatkan N-total, P-tersedia dan K-dd dibandingkan dengan kompos murni., Degradation in soil quality, such as a decrease in soil fertility has occurred at PT. Great Giant Pineapple (GGP) due to monoculture pineapple cultivation since the 1980s. Soil quality can be improved by the application of soil ameliorants. The application of compost as a soil ameliorant has been carried out by PT. GGP, but the effect is not optimal, so it is necessary to add other soil ameliorants. Other soil ameliorant alternatives are coal ash waste (fly ash and bottom ash or FABA) and lignite. This study aims to improve soil quality, especially its chemical properties in the pineapple plantation of PT. GGP with the application of FABA and lignite enriched compost. The research was conducted experimentally at the Research and Development experimental area of PT. GGP Block 86 A uses a Split Plot Design. The treatments consisted of compost, compost+FABA, and compost+FABA+ lignite which is a soil ameliorant material that is applied by spreading it and given in the planting row. The results showed that the enrichment of compost with FABA and lignite increased several chemical properties of the soil ameliorants, including pH, C-organic, P-total, Ca, Mg, K, Mn, and Cu. The application of compost+ FABA+lignite, especially in planting rows, was better in improving some soil chemical properties in PT. GGP, among others, reduces soil acidity and increases C-organic, N-total, P-total, P-available, K-dd, Ca-dd, Mg-dd, Na-dd, CEC, and base saturation. This treatment has not shown a better effect in increasing the total N, P-available, and K-dd compared to compost.
Keyword: compost, FABA, lignite, soil ameliorant

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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