Judul: Viabilitas Formula Konsorsium Bakteri Pelarut Fosfat dan Penambat Nitrogen dalam Talek Sebagai Bahan Pembawa
Abstrak: Pupuk hayati dalam bentuk konsorsium bakteri dalam bahan pembawa tertentu lebih efektif dalam memacu pertumbuhan tanaman. Dua isolat bakteri pelarut fosfat dan dua isolat bakteri penambat nitrogen telah diuji kemampuannya dalam melarutkan fosfat dan menambat nitrogen, serta diuji antagonismenya antar isolat. Hasil uji secara in vitro menunjukkan bahwa keempat isolat tidak bersifat antagonis satu sama lainnya. Isolat terpilih dari hasil uji pelarutan fosfat dan penambatan nitrogen, yaitu Serratia marcescens KAHN 15.12 dan Pseudomonas luteola A13 digunakan sebagai konsorsium bakteri dalam pembuatan formula. Pembuatan formula bakteri menggunakan bahan pembawa yaitu talek dengan penambahan CaCO3 dan Carboxymethyl cellulose (CMC). Uji viabilitas formula menunjukkan terjadinya penurunan jumlah sel bakteri setelah 2 bulan penyimpanan. Jumlah sel pada formula konsorsium KAHN 15.12 dan A13 turun sebesar 27%, tetapi masih menunjukkan kemampuan dalam melarutkan fosfat dan menambat nitrogen.
Keyword: Phosphate-solubizing bacteria, nitrogen-fixing bacteria

Judul: Biofertilizer Consortium Formulation and Its Application on Corn Plants.
Abstrak: Pupuk hayati merupakan pupuk yang mengandung mikrob hidup yang dapat membantu penyediaan unsur hara yang dibutuhkan untuk pertumbuhan dan perkembangan tanaman. Penelitian ini bertujuan menguji formula pupuk hayati yang berisi konsorsium bakteri non-aktinomiset, cendawan, dan aktinomiset terpilih dengan bahan pembawa cair, berdasarkan kestabilan viabilitas sel mikrob, dan aplikasinya pada tanaman jagung. Uji efektivitas terhadap tanaman jagung dilakukan di rumah kaca menggunakan rancangan acak kelompok satu faktor antara kombinasi dosis pupuk N, P, K dan pupuk hayati dengan tiga ulangan. Isolat yang digunakan yaitu Bacillus thuringiensis SAHA 12.12, Lactobacillus plantarum IN05, Rhizobium sp. R1KG, Sacharomyces cerevisiae L1, Streptomyces sp. A4J, dan Trichoderma sp. T2J yang dikonsorsiumkan dengan bahan pembawa cair. Formula pupuk hayati disimpan selama 8 minggu dan dilakukan uji viabilitas setiap satu bulan selama penyimpanan. Hasil uji menunjukkan viabilitas mikrob menurun setelah disimpan selama delapan minggu dan penurunan paling tinggi pada Streptomyces sp. Aplikasi formula konsorsium pupuk hayati memberikan pengaruh nyata terhadap panjang akar, diameter batang, bobot kering tajuk, bobot tongkol berkelobot, dan bobot biji tongkol. Pemberian formulasi konsorsium hayati kombinasi perlakuan P1M2 (kombinasi 50% pupuk N, P, K dan 100% formulasi pupuk hayati) dapat mengurangi penggunaan N, P, K sebanyak 50% dari dosis rekomendasi., Biofertilizer is a fertilizer that contains live microbes that help the plants to obtain nutrients needed for growth and development. This study aimed to observe the effectiveness of a biofertilizer formula containing a consortium of selected bacteria, fungi, and actinomycetes with liquid carrier materials to maize based on the stability of microbial cell viability and its application. The experiment was conducted in a greenhouse using a randomized block design with one-factor which consisted of a combination of N, P, and K fertilizers and biological fertilizers with three replications. The isolates used in thus experiment were Bacillus thuringiensis SAHA 12.12, Lactobacillus plantarum IN05, Rhizobium sp. R1KG, Saccharomyces cerevisiae L1, Streptomyces sp. A4J, and Trichoderma sp. T2J which were combined as a consortium with liquid carrier material. The formula was stored during 8 weeks, and every weeks was analyzed to observed its viability. The results showed that microbial viability decreased after being stored for eight weeks and the highest decrease was shown by Streptomyces sp. The biofertilizer consortium formula applied to corn significantly influenced the growth and production, including root length, stem diameter, crown dry weight, husk cobs, and cob seed weight. Biological consortium formulations PIM2 can reduce N, P, and K application up to 50% of the recommended dose.
Keyword: aktinomiset, Bacillus, Jagung, Pupuk hayati, Viabilitas

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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