Judul: Cempedak Seed Seedball Trial enriched with Trichoderma spp. in West Kalimantan Bauxite Post-mining Land
Abstrak: Kegiatan pertambangan memiliki dampak gangguan lingkungan antara lain hilangnya vegetasi hutan, flora dan fauna serta lapisan tanah pucuk. Perbaikan lahan bekas tambang dapat dilakukan dengan kegiatan revegetasi salah satunya dengan penanaman jenis pohon cempedak (Artocarpus integer). Penggunaan media seedball yang diperkaya Trichoderma spp. diharapkan dapat meningkatkan daya kecambah serta pertumbuhan bibit cempedak. Tujuan penelitian ini yaitu untuk Menganalisis pengaruh seedball yang diperkaya dengan Trichoderma spp. terhadap persen kecambah dan persen hidup benih cempedak dan pertumbuhan bibit cempedak di lahan bekas tambang bauksit. Penelitian ini menggunakan rancangan acak lengkap (RAL) dengan dua belas perlakuan dan lima ulangan. Perlakuan terdiri dari pasangan perlakuan metode penanaman (media seedball dan penanaman secara langsung) dengan berbagai dosis Trichoderma spp. 0 g, 5 g, 10 g, 15 g, 20 g, dan 25 g. Benih cempedak yang ditanam memiliki persen kecambah dan persen hidup sebesar 100% untuk semua perlakuan. Perlakuan K (Trichoderma 25 g dengan seedball) memberikan hasil terbaik pada parameter laju perkecambahan, nilai kecambah, diameter, dan jumlah daun semai cempedak. Perlakuan I (Trichoderma 20 g dengan seedball) menunjukkan respon terbaik pada parameter tinggi semai cempedak.
Keyword: diameter, forest, Trichoderma spp., vegetation

Judul: Seedball and Bioenzyme Application for Land Reclamation Post Limestone Mining, Gunung Putri, Bogor.
Abstrak: Mining causes a decrease in land carrying capacity and soil fertility, so it is necessary to reclaim ex-mining land. To accelerate and reduce the cost of ex-mining land reclamation activities, it is necessary to make technological breakthroughs. Forest rehabilitation using seedball has been widely reported, but has not yet been tested on ex-mining land. Seedball is a technique of seed wrapping to protect seeds from predators and extreme environmental conditions, and provide initial nutrition to seeds after germination. Bioenzymes and manure are needed to support seedling growth in ex-mining lands, which are generally nutrient-poor. The purpose of this study was to find the right composition of seedball ingredients for planting durian (Durio zibethinus), jackfruit (Artocarpus heterophyllus), bisbul (Diospyros blancoi), merbau (Intsia bijuga) and gmelina (Gmelina arborea) seeds on lime ex- mining land, analyzed the effect of seedball and bioenzyme application on plant growth used and analyzed mycorrhizal colonization on plant roots used in limestone ex-mining land. The seedball formulation test used three formulations, namely Formula A (clay and compost), Formula B (clay, compost, and insecticide), and Formula C (clay, sawdust, vermicompost, and bone meal). The design used was a factorial Completely Randomized Design (CRD) with 2 factors. The first factor is the seedball formula, and the second factor is the type of plant where each treatment combination was repeated 3 times. After the best formula was obtained, a planting test was carried out on PT SBI's ex-mining land using the best formula. At the age of 12 weeks after planting (MST) the seeds were given bioenzymes and manure with a Split Plot design. Furthermore, the parameters of germination, germination rate, seedling height, stem diameter, number of leaves, and mycorrhizal colonization on seedling roots were observed by staining method. The result of this research is the best seedball’s formulations is formula C. The results of the planting test on the ex-mining land of PT SBI were the seeds that grow well are jackfruit and merbau. The best fertilization treatment is a combination of bioenzymes and manure. The roots of all plant species in the study area were also colonized by mycorrhizae, and the highest colonization was found in gmelina with a colonization percentage 80.95%. Based on the description above, it can be concluded that the best compositions for making seedballs are clay, sawdust, vermicompost, and bone meal (8:8:2:1), and the seedball technique, application of bioenzymes and manure using jackfruit and merbau types can be used to accelerate the reclamation and rehabilitation of ex-limestone mining land., Pertambangan menyebabkan penurunan daya dukung lahan dan kesuburan tanah, sehingga perlu dilakukan reklamasi lahan bekas tambang. Upaya untuk mempercepat dan menekan biaya kegiatan reklamasi lahan bekas tambang diperlukan terobosan teknologi. Rehabilitasi lahan menggunakan seedball telah banyak dilaporkan, tetapi belum diujicobakan di lahan bekas tambang. Seedball merupakan teknik pembungkusan benih untuk melindungi benih dari predator dan kondisi lingkungan yang ekstrim, serta untuk memberikan nutrisi awal pada benih setelah berkecambah. Bioenzim dan pupuk kandang diperlukan untuk mendukung pertumbuhan bibit di lahan bekas tambang yang miskin hara. Tujuan dari penelitian ini adalah menemukan komposisi bahan pembuat seedball yang tepat untuk menanam
Keyword: seedball, bioenzymes, rehabilitation, degraded land, plant growth

Judul: Model Input-output dalam Masalah Network Flow
Abstrak: Production process is a process, which is done by industry, to transform input into output. According to the type of output and its activity, industry can be classified into various sectors, which are connected to each other. Therefore, a model to analyze the connection among sections is needed. The model is known as input-output model (IO model). IO model presents an IO table, which shows informations about the transaction between goods and services in each economic sector. Furthermore, the IO model also shows that the amount of all input is the same as the amount of all output. In this paper, the transaction of each economic sector in IO table is analyzed using network flow theory. The formulated network flow problem implies that each sector represents partly as a producer and also as a consumer. This paper also solves a minimum cost circulation problem.
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