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: Peningkatan populasi dan keragaman fauna tanah melalui pengelolaan hayati tanah pada budidaya System of Rice Intensification (S.R.I.) di Kecamatan Cibungbulang, Kabupaten Bogor
Abstrak: Soil fauna is important component in the soil ecosystem. They play a very important role in organic matter decomposition, nutrient cycling, nutrient availability and uptake, soil physical properties, prevention of nutrient leaching, and maintain plant health through natural predation and parasitism of plant pathogens and pest. Land management practice can affect soil fauna population and diversity, therefore land management should be environmental frindly, in order to preserve the ecosystem and consequently improve diversity of the soil fauna. In the rice field ecosystem, modification of bund distance is one of managements to improve population and diversity of soil fauna. This research aimed to evaluate the effect of different bund distance (4m and 8m) on soil fauna population and diversity in System of Rice Intensification (S.R.I.). S.R.I. is an innovative cultivation technique to increase yields. The basic principles of S.R.I. method are the use of young seedling of 8-12 days old, wide spacing of 30 cm x 30 cm, maintain unflooded soil condition and planting with a single seed. The research was conducted in Cibungbulang sub district of Bogor regency and Laboratory of Soil Biotechnology of Soil Science and Land Resource Department, Bogor Agricultural University. The research used a treatment of bund distance with two levels (4m and 8m) and four replications. The result showed that the abundance and biomass of soil fauna in plot with 4m bund distance (4m plots) were 26259 individual/m2 and 11.7 g/m2, respectively, and plot with 8m bund distance (8m plots) were 8402 individual/m2 and 2.3 g/m2, respectively. Abundance and biomass of soil fauna in 4m bunds were 25343 individu/m2 dan 10.8 g/m2, respectively, meanwhile in 8m bunds were 19611 individu/m2 and 6.4 g/m2, respectively. The cultivation of soybean in the bund was proven to be able to increase soil fauna population in the bund, that can be seen from 0 day to 90th days. Diversity Index calculated according to Shannon Diversity Index showed the low value (< 1.5) in both 4m plots and 8m plots. The most dominant animals in 4m and 8m plots was Collembola, meanwhile in the bunds was Hymenoptera. The rice productivity determined by the parameters of yield (ton/Ha), filled and empty grain percentage (%), and weight of 1000 grains (g) showed a higher value in 4m plots, as compared to 8m plots. The results in 4m plots based on parameters above were 5.08 ton/ha, 82.64 % 17.36 % and 26.87 g, respectively, meanwhile in 8m plots were 4.96 ton/ha, 76.39 %, 23.61 % and 26.29 g, respectively.
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Judul: Kombinasi algoritma sha 1 dan algoritma rsa untuk membentuk tanda tangan digital
Abstrak: Tanda tangan digital termasuk ke dalam teknik kriptografi yang memanfaatkan teknologi kunci publik (enkripsi asimetris). Tanda tangan digital dapat dibuat dengan mengkombinasikan teknik hashing (untuk membentuk message digest dari pesan asli) dan enkripsi asimetris (untuk membentuk kunci publik dan kunci privat). Teknik hashing yang digunakan adalah teknik rashing satu arah dengan menggunakan algoritma SHA 1, sedangkan algoritma RSA digunakan untuk enkripsi asimetris Tulisan ini bertujuan untuk mempelajari, menganalisis, dan mengimplementasikan pembentukan dan verifikasi tanda tangan digital menggunakan dua metode, yaitu dengan mengkombinasikan algoritma SHA 1 dan algoritma RSA dan dengan menggunakan algoritma RSA saja. Analisis yang dilakukan pada kedua algoritma ini meliputi analisis algoritma, dan analisis hasil implementasi. Analisis terhadap algoritma SHA | menunjukkan bahwa algoritma ini memiliki kompleksitas O(n) untuk kasus terburuk. Sedangkan untuk pembentukan kunci publik dan kunci privat dengan algoritma RSA diperlukan beberapa algoritma pendukung, yaitu algoritma Miller Rabin, Witness, Euclid, dan Extended Euclid. Semua algoritma pendukung tersebut memiliki kompleksitas waktu yang sama, yaitu O(k), dengan adalah panjang representasi bit bilangan bulat. Kompleksitas waktu yang didapatkan untuk proses pembentukan tanda tangan digital dengan kedua metode ini adalah sama yaitu O(nk). Untuk proses verifikasi, kompleksitas waktu yang didapatkan dengan menggunakan kombinasi dua algoritma adalah O(1 + k) dan untuk algoritma RSA adalah O(n + k). Pada proses pembentukan tanda tangan digital menggunakan kombinasi dua algoritma yang ditandatangani adalah message digest yang dihasilkan oleh algoritma SHA 1, sedangkan pada algoritma RSA yang ditandatangani adalah pesan itu sendiri. Dari hasil implementasi didapatkan untuk proses pembentukan tanda tangan digital menggunakan kombinasi dua algoritma lebih cepat dibandingkan dengan menggunakan algoritma RSA saja untuk file-file yang berukuran besar, dst
Keyword: Tnda Tangan Digital, Teknik Kriptografi, Enskripsi Asimetris