Judul: Populasi dan Keragaman Fauna Tanah Pada Areal Pertanaman Padi Gogo Dengan Teknologi Peresapan Biopori di Kebun Percobaan Cikabayan IPB
Abstrak: Population and diversity of soil organisms can negatively affected by intesive tillage in dry land agriculture because they are very susceptible to land management activities. The most susceptible organisms to soil tillage are organisms with larger body size, such as soil animals. Minimum tillage is therefore needed to reduce the negative impacts of intensive-land preparation. Minimum tillage is the efforts to minimize the change of soil physical, chemical and biological characteristics due to intensively soil tillage which is suited to principles of soil and water conservation. The minimum soil tillage is expected to be able to provide a space for soil fauna to live and grow. The research was aimed to study the population and diversity of soil fauna on five different land treatments based on soil and water conservation systems, namely: 1). Control (T0), 2). “Gulud” Terrace with Conventional Ditch (T1), 3). “Gulud” Terrace with Conventional Ditch Combined by Biopore-Infiltration Hole (T2), 4). “Gulud” Terrace with Biopore-Infiltration Ditch (T3), 5). Biopore-Infiltration Ditch Combined by Biopore-Infiltration Hole (T4), in Cikabayan-Research Farm, IPB with two different slopes (5% and 15%). Soil fauna was extracted from soil samples using Berlese Funnel Extractor, meanwhile for larger animals were used Hand Sorting Method. The research results indicated that land with 5% slope had a highest soil fauna abundance in the T4-treatment, and followed by the treatment of T3, T2, T1 and T0, respectively (first period). In the second period, the highest soil fauna abundance was indicated by the treatment of T2, and followed by T4, T3, T1 and T0, respectively, meanwhile in the third period the highest soil fauna abundance was shown by the treatment of T2, and followed by T4, T1, T3 and T0, respectively. Land with 15% slope showed that the highest soil fauna abundance was the T4-treatment, and followed by the treatment of T3, T0, T2 and T1, respectively (first period). In the second period, the highest soil fauna abundance was indicated by the treatment of T3, and followed by T4, T2, T0 and T1, respectively, meanwhile in the third period the highest soil fauna abundance was shown by the treatment of T3, and followed by T2, T4, T1 and T0, respectively. The results indicated that treatments which were able to increase soil fauna abundance were T2 and T4, i.e. treatment with vertical mulch, biopore-infiltration ditch combined by biopore-infiltration hole. Treatments of T2 and T4 had a higher amount of organic material as a sources of food for soil fauna compared to the other treatments, thus it could be able to atrract soil fauna. The diversity of soil fauna which describes number of taxa (group) in a habitat was calculated based on Shannon’s Diversity Index. The treatment that showed highest soil fauna diversity was treatment of T3 and T4. In the land with 5% slope, soil fauna was dominated by Centipede, meanwhile land with 15% slope was dominated by Hymenoptera.
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Judul: Aplikasi Teknologi Sistem Peresapan Biopori Untuk Mencegah Aliran Permukaan Dan Erosi Serta Peningkatan Produksi Tanaman Pada Tanah Latosol Darmaga
Abstrak: Surface runoff and erosion are the main problem causing land degradation on sloping upland agriculture. Biopore infiltration system is one of water harvesting technology developed on arid region. The experiment aimed at studying the effect of biopore infiltration system to control surface runoff and erosion on sloping upland. The research was conducted in Cikabayan experimental farm, University Farm, Bogor, and in ITSL Laboratory, Faculty of Agriculture, Bogor Agricultural University. The Research was done from January 2009 until March 2010. The objective of this research to study the effectiveness of the biopori infiltration system in preventing damage to land by surface runoff and erosion, as well as in improving agricultural production on upland. Completely randomized block experimental design was used to analyze data collected from five treatments arranged randomly in three blocks as replications. Applied treatments were: control (T0); ridge terrace with contour channel according to the size of a width of 20 cm and 15 cm deep in intervals of 2 m (T1); T1 treatment combined with vertical mulching 4 tons of rice straw/ha (T2); T1 treatment combined with 2 infiltration hole in the contour channel at intervals of 1 m, diameter 8 cm and 100 deep, filled with rice straw (T3); and combinations of treatments T2 and T3 (T4). Research results indicated that each treatment very significantly prevents runoff and erosion for corn planting season and upland rice planting season compared to treatment T0. All treatments tends to increasing plant heigh of maize and upland rice except treatment of T2 at corn planting season to treatment T0. Treatment T2, T3, and T4 very significantly increase number of produvtive tillers compared to treatment T0. All treatments tends to increasing dry seed wight compared to T0 except treatment of T4 which is real increased dry seed wight. Treatment with vertical mulch (T2, T3, and T4) had higher seed wight if it is compared to treatment without vertical mulch (T1). All treatments very significantly increase dry rice grain wight if it is compared to T0. Treatment of T3 and T4 tends to produce higher rice grain if it compared to treatment of T1 and T2. Treatment with vertical mulch (T2, T3, and T4) very significantly increased the weight of dry straw if it is compared to treatment T0.
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Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular