Judul: Dinamika Penetrabilitas Tanah pada Berbagai Penggunaan Lahan di Tanah Latosol, Darmaga
Abstrak: Plant roots that functioning to absorb water and nutrients can be inhibited when soil penetrabilty is quite high. Soil penetrability can be affected by soil properties, for example texture, bulk density, organic matter content, soil water content, matrix potential, calcium carbonate, and types of clay mineral. Of the soil properties, there are some that can be influenced by the type of land use. This study examined the penetrability of soil in various land uses. There was a series of observation of soil penetrability and soil properties in a variety of land use conducted in this research in order to study the relationship of soil properties on soil penetration resistance, soil water content relationship with penetrability, and resistance dynamics of land penetration in various land uses. The results showed that the soil texture class in the three land uses was clay. The highest clay percentage was found in grasslands both in the depth of 0-10 cm (82.00%) and 10-20 cm (81.90%). The highest soil bulk density in the depth of 0-10 cm was found in grasslands (1.09 g/cm3) and in the depth of 10-20 cm was found in mixed farms (1.13 g/cm3). The organic matter content in the depth of 0-10 cm was found in mixed farms (4.80%) and in the depth of 10-20 cm was found in secondary forest (3.18%). The index of soil aggregate stability of the three land uses were classified as a very stable class. Soil total pore space in the depth of 0-10 cm was found in secondary forest (61.52%) and in the depth of 10-20 cm was found in grasslands (59.15%). The three land uses had higher micro pore compared to the micro pore them selves. The different properties of soil had different effects on soil penetration resistance. Grassland showed the highest value of soil penetrability because of its high level of soil bulk density and clay. Secondary forest had the lowest soil penetrability value due to its high soil organic matter, low soil density, low micro pore space, and very stable soil aggregates. The relationship of soil penetration resistance with water content in three land uses was presented in power regression models with different determination coefficient. In the depth of 0-10 cm, the relationship had R2 of 0.53 in secondary forest, 0.35 in mixed farms, and 0.19 in grasslands. In the depth of 10-20 cm, the relationship of soil penetrability with moisture content had R2 of 0.29 in secondary forest, 0.26 in garden mix, and 0.11 in grasslands. In the days of no rain, the resistence of soil penetration had increased sharply since the third day in secondary forests, since the fifth day in mixed farms, and since the fourth day in grasslands in 0-20 cm deep. The resistence of soil penetration at each land use after 12 days of no rain increased because the soil was drier and harder, however, it did not inhibit the growth of plant roots.
Keyword: physical properties of soil, land use, penetration resistance, water content, Bogor Agricultural University (IPB)

Judul: Keragaan Infiltrasi Tanah Latosol pada Beberapa Penggunaan Lahan di DAS Ciujung
Abstrak: Land use is an important aspect in maintaining ecosystem sustainability, particularly in the watershed ecosystem. Land use determines to physical, chemical, and biological characteristics of soil. These soil characteristics influence to the growth of plants and the performances of water infiltration into soil. Infiltration is an essential part of the hydrological cycle that has an important role water availability in the soil. Infiltration process have an important role to the distribution of rainfall and control to runoff, flood, erosion and ground water storage and finally will determines the availability of river discharge in dry season. The aims of this research is to assess the performance of soil infiltration in various land use in Ciujung watershed. The study was conducted on three land use types that included plantative forest (HT), dense mixed garden (KCR), and less-dense mixed garden (KCTR). The field observation was done by using the Double Ring infiltrometer method, while the the analysis of the physical and chemical and other soil characteristics were done in the Laboratory of Soil and Water Conservation, Department of Soil Science and Land Resources, Faculty of Agriculture. The results of this research showed that the infiltration rate is strongly influenced by land use. Infiltration rate is the highest and most stable on HT land use, followed by KCR and KCTR. Constant infiltration rate at HT and KCR is belonging to quickly class, while at KCTR is relatively moderate to fast. The magnitude of the rate constant infiltration in HT (23.4 cm h-1) is higher than KCR (13.2 cm h-1) and KCTR (6.0 cm h-1). The high rate infiltration of the soil on the land use of HT support it able to accommodate as much water (6.45 dm3) that higher than at KCR (3,66 dm3) and at KCTR (1.52 dm3). Infiltration rate is influenced by pores with large size (PDSC), while the volume of water infiltration is more influenced by the total porosity of the soil. Besides it is influenced by land use, soil infiltration in the study area is also determined by the physical and chemical characteristic of the soil organic matter, bulk density, total porosity, aggregate stability, macro pores, very fast drainage pore (PDSC), and soil texture.
Keyword: Bogor Agricultural University (IPB), infiltration volume., physical and chemical characterstics of soil, land use, Infiltration rate

Judul: Pengklonan gen VP28 Penyandi Viral Protein-28 dari virus white spot syndrome sebagai langkah awal produksi vaksin rekombinan udang penaeid
Abstrak: Usaha produksi udang dalam negeri saat ini sedang mengalami kendala akibat serangan penyakit white spot syndrome virus (WSSV) pada jenis udang windu (Penaeus monodon). WSSV yang termasuk virus DNA berukuran besar dapat menginfeksi udang dan berbagai jenis crustaceae lainnya. Virus ini merupakan patogen yang sangat ganas dan paling serius menyerang udang. Serangannya begitu cepat, sangat sulit dihentikan dan dapat mematikan 100% udang peliharaan dalam waktu 3-10 hari setelah munculnya gejala klinis. Serangan virus ini juga telah menghancurkan industri udang di berbagai negara. Infeksi WSSV ditandai dengan adanya bintik putih atau bercak putih pada eksoskeleton dan epidermis terutama pada bagian karapas udang. Hingga saat ini belum ada cara tradisionalyang efektif mencegah dan menanggulangi penyakit ini.
Keyword: