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: Population and Diversity of Soil Fauna in Gogo Rice Cultivation with Biopore-Technology Application in Cikabayan-Research Farm, 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: 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