Judul: Analisis Produksi Biomassa Tanaman Singkong (Manihot esculenta) Pada Tiga Tanah (Latosol Cikarawang, Regosol Sindang Barang, dan Andisol Sukamantri)
Abstrak: Cassava is a tropical plant that extensively cultivated at Africa, Asia and South America. In the world, Indonesia is the fourth largest of cassava producer after Nigeria, Brazil, and Thailand. In Indonesia, cassava has long been recognized as carbohydrate source as well as food source. For food diversification, cassava is also widely used for snacks. Cassava is used as raw material for tapioca, syrop, sorbitol, monosodium-glutame, ethanol industries, and othe processed forms. However, those utilization limited only from the cassava tuber. Overall potential production of cassava, including tuber, tuber skin, stem, and leaves was studied. Field observation and biomass production measurement of cassava at harvest time (was conducted in three cassava cultivations which different in their soils, i.e. Latosol Cikarawang, Regosol Sindang Barang, and Andisol Sukamantri. At the same time, composite soil sampling for soil fertility analysis was conducted. Laboratory analysis of N, P, and K of soil samples and each of biomass part of cassava was conducted. In addition, tuber was analyzed for its carbohydrates, fats, and protein; while stem was analyzed for its holocellulose and lignin. The results of soil fertility analysis indicated that in general Regosol Sindang Barang has the highest fertility, followed by Andisol Sukamantri and Latosol Cikarawang. The highest overall dry (65ºC) biomass was produced on Latosol Cikarawang 29.8 ton/ha, the highest tuber without skin was produced on Latosol Cikarawang 27.1 ton/ha, the highest trunk and leaves were produced on Andisol Sukamantri 3.2 and 1.3 ton/ha. The highest tuber skin were produced occur in common to Latosol Cikarawang and Regosol Sindang Barang 0.8 ton /ha. Average carbohydrate, protein, and fat of the tuber without skin produced on the three soils were 74.80%, 2.64%, and 0.42%, respectively. Meanwhile, average holocellulose and lignin of the stem produced on the three soil were 49.22% and 20.73%. Total nutrients uptake by the overall biomass on the three soils were in the range of 83.8-166.4 kg/ha, 17.6-54.4 kg/ha, and 106.5-217.8 kg/ha, respectively for N, P, and K. Both tuber without skin and stem of cassava are potential for the future production of bioethanol. In order to maintain soil productivity, it is suggested that the tuber skin and the leaves should be returned to the soil. If the tuber skin and the leaves both were returned to soil, it is equivalent with 44.2-74.3 kg Urea/ha, 16.6-26.7 kg SP-36/ha, and 38.6-85.1 kg KCl/ha.
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Judul: Pertumbuhan dan Produksi Ubi Kayu (Manihot esculenta Crantz) pada Sistem Tumpang Sari dengan Bengkuang (Pachyrhizus erosus L.).
Abstrak: Produksi ubi kayu di Indonesia mengalami peningkatan produksi 10 tahun terakhir dari 19,32 juta ton pada tahun 2005 menjadi 21,79 juta ton pada tahun 2015. Luas areal panen turun dari 1,21 juta ha menjadi 949 ribu ha. Lahan produktif di Indonesia semakin berkurang dari tahun ke tahun. Produksi tanaman mengarah pada lahan marjinal dengan hara atau kesuburan yang rendah. Peningkatan produksi dan perbaikan hara perlu dilakukan, salah satunya dengan penanaman ubi kayu secara tumpang sari dengan tanaman kacang-kacangan. Penelitian ini bertujuan mengetahui pertumbuhan dan produksi beberapa varietas ubi kayu pada sistem tumpang sari dengan bengkuang. Tiga varietas ubi kayu (Mangu, Gajah dan Adira 1) ditanam monokultur dan tumpang sari dengan bengkuang. Varietas berpengaruh terhadap pertumbuhan ubi kayu seperti tinggi tanaman, diameter batang, jumlah daun segar, jumlah daun gugur, bobot basah dan kering daun gugur. Ubi kayu pada sistem tanam tumpang sari mempunyai tinggi tanaman dan diameter batang yang lebih besar. Perlakuan sistem tanam tumpang sari meningkatkan jumlah umbi pertanaman, bobot basah dan kering brangkasan dan varietas adira mempunyai bobot basah dan kering tertinggi. Sistem tanam tumpang sari antara ubi kayu dan bengkuang tidak mampu meningkatkan produktivitas ubikayu. Hasil umbi ubi kayu terbesar terdapat pada varietas Mangu yaitu 4,27 kg tanaman-1 atau 34,16 ton ha-1 Interaksi varietas dan sistem tanam tidak menghasilkan pengaruh terhadap pertumbuhan dan produksi ubi kayu maupun bengkuang. Penanaman ubi kayu secara tumpang sari mampu menaikkan nilai unsur hara N, P, K dan Al., Productivity of cassava in Indonesia increased in last 10 years from 19,32 million ton hectare-1 in 2005 to 21,79 million ton hectare-1 in 2015. However the cassava field decreased from 0.949 to 1.21 million ha. Productive land in Indonesia is decreasing almost every year. Planting in the marjinal land with low nutrient contents will cause low productivity of casava. One of the way to increase productivity and nutrient content is an intercropping casava and legume. In this study, three variety of cassava were used are Mangu, Gajah and Adira-1. The variety was planted in monoculture and intercropping. Variety affect in plant height, stem diameter, number of attached leaves, number of fallen leaves, fresh and dry weight of cassava leaves. The casava intercropped have the plant height and stem diameter more than in the monoculture, but intercropping between cassava and yam bean did not increase cassava productivity. The treatment of intercropping system increased number of cassava tuber per plant, fresh and dry biomass of cassava and Adira has fresh and dry biomass biggest. The highest tuber of cassava produced by Mangu variety with 4,27 kg per plant or 34,16 ton per hectare. The interaction of variety and cropping system not affect in the growth and production of cassava and yam bean. The intercropping system in casava increase amount of Nitrogen, Pottasium, Kalium and Al in the soil.
Keyword: cassava, growth, intercropping, production, yam bean

Judul: Query Expansion based on Bilingual Dictionary Using Conditional Probability
Abstrak: Query expansion is a technique that can be used to bridge vocabulary gaps between queries and documents in the collection. With query expansion, user will be helped to formulate queries well so that user will optimize the search result. In this study, the expansion term was resulted from the translation of bilingual dictionary. Subsequently, several terms of expansion were elected based on the closeness of its relationship with the original query. This research showed that conditional probability can be used to select expansion term in bilingual translation method query expansion. The result of 1000 documents was more than 97% relevan document can be retrieved by this system. The more expansion term used, the larger number relevan document was retrieved.
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