Judul: Effects of Fly Ash-Bottom Ash Application Residues and Bromelain Hydrolyzate Bioherbicide on Weeds, Growth, and Yield in Tomatoes
Abstrak: Pengendalian terhadap gulma dapat dilakukan melalui berbagai cara, salah satunya yaitu penggunaan bioherbisida yang ramah lingkungan. Senyawa yang ada di dalam tumbuhan berpotensi dijadikan sebagai bioherbisida organik. Salah satunya berasal dari limbah nanas berupa enzim bromelain. Penelitian ini bertujuan menganalisis efektivitas bioherbisida berbahan baku limbah bromelain terhidrolisa dalam mengendalikan gulma pada tanaman tomat, mengidentifikasi pengaruh bioherbisida berbahan baku limbah bromelain terhidrolisa dan media tanam Fly ash dan bottom ash (FABA) terhadap pertumbuhan gulma pada tanaman tomat, dan mengidentifikasi pengaruh bioherbisida berbahan baku limbah bromelain terhidrolisa dan media tanam FABA terhadap pertumbuhan dan hasil tanaman tomat. Penelitian dilaksanakan di Kebun Percobaan Leuwikopo dan Laboratorium Ecotoxicology Waste and Bioagent, IPB Dramaga, Bogor, Jawa Barat pada bulan September 2023 hingga Januari 2024. Percobaan pertama dilakukan untuk mengamati pengaruh residu FABA pada media tanam terhadap pertumbuhan vegetatif dan generatif tanaman tomat. Perlakuan residu FABA tidak memberikan pengaruh nyata terhadap pertumbuhan vegetatif dan generatif tanaman tomat. Percobaan kedua dilakukan untuk mengetahui pengaruh bioherbisida hidrolisat bromelain terhadap gulma fase preemergence, early post emergence, dan post emergence. Perlakuan 80% Glifosat + 20% Bioherbisida menghasilkan persen penekanan gulma daun lebar pada fase early post emergence sebesar 19,89% dan sebesar 60,06% pada penekanan gulma Euphorbia hirta. Komposisi residu 0,8 kg FA + 0,2 kg BA + 15 kg tanah memiliki jumlah daun dan luas daun yang paling besar dibandingkan dengan perlakuan lainnya. Komposisi residu media tanam 0,4 kg FA + 0,1 kg BA + 15,5 kg tanah memberikan hasil produksi buah terbaik pada tanaman tomat yang diukur berdasarkan bobot buah per tanaman, bobot setiap buah, dan diameter buah., Control of weeds can be done in various ways, one of which is the use of bioherbicides which are more environmentally friendly. Compounds in plants have the potential to be used as organic bioherbicides, namely pineapple waste, is the enzyme bromelain. The research objectives are to analyze the effectiveness of bioherbicides made from hydrolyzed bromelain waste in controlling weeds on tomato plants, determine the effect of fly ash and bottom ash (FABA) planting media on weed growth on tomato plants, and determine the effect of bioherbicides made from hydrolyzed bromelain waste and FABA planting media on the growth and yield of tomato plants. The research was carried out at Leuwikopo and the Ecotoxicology Waste and Bioagent Laboratory, IPB Dramaga, Bogor, West Java from September 2023 to January 2024. The first experiment was carried out to observe the effect of various concentrations of FABA residue in the planting medium on the vegetative and generative growth of tomato plants. Treatment with various concentrations of FABA planting media residue did not have a significant effect on the vegetative and generative growth of tomato plants. The second experiment was carried out to determine the effect of applying bromelain hydrolyzate bioherbicide on the number of weeds in the preemergence, early post emergence, and post emergence phases. Treatment of 80% Glyphosate + 20% Bioherbicide resulted in a percent suppression of broadleaf weeds in the early post emergence phase of 19.89% and 60.06% suppression of Euphorbia hirta weeds. The residue composition of 0.8 kg FA + 0.2 kg BA +
Keyword: daun lebar, rumput, teki, glifosat, organik, logam berat

Judul: Improvement of Silt Textured Soil from Belitung Island with FABA Enriched Compost and Its Effect on Tomato Plant Growth
Abstrak: Tanah Pulau Belitung secara umum memiliki pH masam dengan rata-rata pH di bawah 5. Pulau Belitung memiliki Pembangkit Listrik Tenaga Uap (PLTU) yang menggunakan batubara sebagai bahan bakarnya. Proses pembakaran batubara menghasilkan residu bahan padat berupa fly ash dan bottom ash (FABA). Sifat kimia FABA menunjukkan bahwa FABA berpotensi dimanfaatkan sebagai pembenah tanah. Pemberian FABA perlu ditambah kompos sebagai sumber bahan organik dan mikoriza untuk meningkatkan efisiensi penyerapan unsur hara. Penelitian ini bertujuan mengidentifikasi pengaruh pemberian kombinasi kompos, FABA dan mikoriza terhadap pertumbuhan tanaman tomat dan karakteristik bahan tanah bertekstur debu dari Pulau Belitung. Penelitian dilakukan dengan membandingkan karakteristik tanah sebelum perlakuan dengan tanah setelah perlakuan dan pengaruhnya terhadap pertumbuhan tanaman tomat. Hasil penelitian menunjukkan bahwa pemberian kompos diperkaya FABA berpengaruh terhadap peningkatan pH, KTK, C-organik dan unsur makro seperti N, P, K, Ca, Mg. Perlakuan terbaik dicapai pada K1D1M1, yaitu dosis 75 ton/ha dengan komposisi kompos 75%, FABA 25%, dan mikoriza 5 g/4 kg., Soil in Belitung Island generally has an acidic pH with an average pH below 5. Belitung Island has an Electric Steam Power Plant that uses coal as its fuel. The coal combustion process produces solid residues in the form of fly ash and bottom ash (FABA). The chemical properties of FABA has the potential to be used as a soil conditioner. The addition of FABA needs to be added compost as a source of organic material and mycorrhizae to increase the efficiency of nutrient absorption. This study aims to identify the effect of combination of compost, FABA, and mycorrhizae on the growth of tomato plants and the characteristic silt-textured soil materials from Belitung Island. The study was conducted by comparing the characteristics of the soil before treatment with the soil after treatment and its effect on the growth of tomato plants. The results showed that FABA enriched compost had an effect on increasing pH, CEC, organic-C, and macro-nutrients such as N, P, K, Ca, Mg. The best treatment was achieved at K1D1M1, which is a dose of 75 tons/ha with a composition of 75% compost, 25% FABA, and 5 g/4 kg mycorrhizae.
Keyword: bottom ash, compost, dust, fly ash, tomato

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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