Judul: Analysis of Soil Puddling Method and The Effect  to Soil Physical Properties and Growth of Rice Crops (Oryza sativa L.)
Abstrak: Pelumpuran tanah sawah adalah kegiatan pengolahan tanah dengan cara mencampur tanah dengan air secara berulang-ulang sehingga terbentuk lumpur. Terdapat dua metode pelumupuran yang sering digunakan petani, yaitu metode pelumpuran satu tahap dan metode pelumpuran dua tahap. Tujuan dari penelitian ini adalah menganalisis sifat fisik tanah hasil dari metode pelumpuran satu tahap dan metode pelumpuran dua tahap serta menganalisis pengaruh metode pelumpuran terhadap pertumbuhan tanaman padi. Penelitian dilaksanakan di lahan sawah percobaan Institut Pertanian Bogor, Desa Cikarawang Kecamatan Dramaga Kabupaten Bogor Jawa Barat. Hasil penelitian menunjukan setelah pelumpuran dengan perlakuan metode pelumpuran satu tahap maupun dua tahap terjadi penurunan nilai dry bulk density, peningkatan nilai porositas, dan peningkatan nilai kadar air. Pertumbuhan tanaman padi setelah 60 HST dengan perlakuan metode pelumpuran satu tahap bobot biomassa keringnya 109,84 gram/rumpun, tinggi tanaman 119,76 cm, dan panjang akar 28,40 cm dengan nilai IP sebesar 70,07 % . Pertumbuhan tanaman padi setelah 60 HST dengan perlakuan metode pelumpuran dua tahap 104,20 gram/rumpun, tinggi tanaman 113,78 cm, dan panjang akar 26,36 cm dengan nilai IP sebesar 60,06 %., Soil puddling is soil tilling activities by mixing soil and water to produce mud. There are two puddling methods commonly used by farmers, namely one-stage puddling method and two-stage puddling method. The purpose of this research is to analyze the physical properties of the soil resulting from the two commonly used puddling methods and to analyze the effect of the puddling method on the growth of rice plants. The research was carried out in experimental rice fields, Bogor Agricultural University, Cikarawang Village, Dramaga District, Bogor Regency, West Java. The results showed that after puddling with the one-stage or two-stage method there was a decrease in the value of dry bulk density, increased porosity value, and increased water content value.The growth of rice plants after 60 DAP with the one-stage puddling method had a dry biomass weight of 109.84 grams/clump, plant height 119.76 cm, and root length 28.40 cm with an IP value of 70.07%. The growth of rice plants after 60 DAP with the two-stage puddling method was 104.20 grams/clump, plant height was 113.78 cm, and root length was 26.36 cm with an IP value of 60.06%.
Keyword: puddling, rice growth, soil physical properties, soil puddling method

Judul: Pengaruh Pemberian Mulsa Jerami Padi dan Kepadatan Tanah terhadap Pertumbuhan dan Produksi Padi Gogo (Oryza sativa L.)
Abstrak: Food security issues are strongly associated to the availability of food and land that affecting plant growth and production. Intensive tillage in conventional farming systems results poor soil condition (low fertility and soil physics characteristic, especially soil compaction) that fail to support plant growth. Soil compaction improvement is one of management effort on soil physics properties to obtain more suited physical environment for plant growth especially paddy. This research was aimed to study the effect of rice straw application and soil compaction on soil physics characteristic and to determine the soil bulk density and dose of mulch that effective for paddy growth and yield. Soil compaction treatment was divided into three soil bulk densities i.e. 0.8, 1.0, and 1.2 g/cm3. Each soil compaction was treated by rice straw mulch application in various doses i.e. 0%, 30%, 60%, and 90% of covered surface. Completed random design is used as experimental design and Honesty Significant Different (HSD) is used to identify the effect of treatment. The results showed that the interaction between soil compaction and mulch affect significantly on plant height in 5 weeks after growing, number of tillers in 4 weeks after growing, wet weight of root, wet biomass, weight of dry grain at harvest, time of harvest. Soil compaction was significantly affecting the field capacity water content, soil resistance before planting, plant height at 7 and 8 weeks after growing, number of tillers at 6, 8, and 9 weeks after growing also dry biomass also water content, bulk density and total of pore spaces after planting. Mulch application had only significant effect on plant height at 6 weeks after harvest. Soil bulk density suited for paddy growth and yields is 1.0 g/cm3 with 90% of mulch dose.
Keyword: upland rice, Situ Patenggang, straw rice mulch, soil compaction

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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