Judul: Pemanfaatan Bahan Organik Tahap Kedua Terhadap Pertumbuhan Tanaman Kacang Hijau (phaseolus radiatus l. Var. Walet) Di Rumah Kaca
Abstrak: Pereobaan dengan penambahan kompos ke dalam tanah marjinal bersama dengan aplikasi asam humat dan Rhizobium telah dilakukan dalam dua tahap penanaman. Tahap pertama telah dilakukan menggunakan komoditi kacang tanah (Arachis hipogaea var. Gajah). Tahap kedua menggunakan medium sisa tahap pertama dengan komoditi kacang hijau (Phaseo/us radiatus L. var. Walet). Pada tahap kedua ini medium tidak mendapatkan tambahan kompos ataupun asam humat, hanya dilakukan aplikasi Rhizobium baru yang berbeda (khusus untuk kacang hijau).
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Judul: Pengaruh pengurangan radiasi dan dosis pemupukan nitrogen terhadap pertumbuhan, perkembangan, hasil produksi dan bobot biomasa pada tanaman kacang hijau (Phaseolus radiatus L.)
Abstrak: Penelitian dilaksanakan di kebun Percobaan Tanaman Pangan Citayam Bogor yang terletak pada posisi 6°27' Lintang Selatan dan 106°49 Bujur Timur dengan ketinggian tempat 115 m dari permukaan laut selama 2 bulan (Januari sampai Maret 1990). Tujuan dari penelitian ini untuk mengetahui: (1) Hubungan pengurangan intensitas radiasi surya dengan pertumbuhan, perkembangan, hasil produksi dan bobot biomasa tanaman. (2) Efisiensi pemupukan nitrogen oleh tanaman kacang hijau pada berbagai pengurangan intensitas radiasi. (3) Persentase naungan dan dosis pemupukan nitrogen yang optimum bagi pertumbuhan, perkembangan, hasil produksi dan bobot biomasa tanaman kacang hijau. Pemberian naungan mengurangi radiasi yang diterima tanaman sehingga mengakibatkan perubahan unsur-unsur iklim seperti: suhu udara dan kelembaban udara di daerah pertanaman serta proses fisiologis tanaman seperti: pertumbuhan tanaman (tinggi tanamar) dan hasil produksi tanaman. Peningkatan naungan mengurangi radiasi yang diterima lingkungan dibawah naungan sehingga menimbulkan perubahan suhu udara dan kelembaban udara, dimana pada naungan yang lebih rapat rataan kelembaban udara cenderung lebih tinggi dan rataan suhu udara lebih rendah dibanding maungan yang kurang rapat. Peningkatan naungan akan menurunkan hasil tanaman, jumlah polong yang terbentuk dan bobot akar tanaman akan tetapi meningkatkan tinggi tanaman dan luas daun tanaman kacang hijau.
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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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