Judul: Kombinasi perlakuan waktu tanam Arachis pintoi dan pemupukan fosfor terhadap pertumbuhan serta produksi jagung hibrida CP-I dibawah pertanaman kelapa
Abstrak: Penelitian ini bertujuan untuk mempelajari kombinasi waktu tanam Arachis pintoi dan pemupukan fosfor terhadap pertumbuhan dan produksi jagung Hibrida Cr-I di bawah pertanaman kelapa dst…
Keyword: Zea may, Hibrida, Arachispintoi, Fertilizer

Judul: Pengaruh pemberian pupuk fosfat, pupuk kandang dan kapur terhadap serapan P dan produksi jagung hibrida
Abstrak: Percobaan dilaksanakan pada tanah Hidromorf Kelabu, pada kemasaman (pH) berkisar 5.0 sampai 6.0 di Kebun Percobaan Balai Penelitian Tanaman Pangan Sukamandi. Percobaan disusun dalam bentuk petak terpisah-pisah dengan petak utama pemberian kapur (0 dan 3.50 ton/ha); anak petak pemberian pupuk kandang (0, 5.0 dan 10.0 ton/ha); anak-anak petak pemberian fosfor (0, 75 dan 150 kg P/ha). Seluruh perlakuan diberi tambahan hara berupa N, K, Zn, Cu dan B. jagung yang digunakan adalah jagung hibrida C1 (PT Cargill). Tanaman interaksi ketiganya terhadap Penelitian bertujuan untuk mengetahui pengaruh pemberian kapur, kandang dan fosfor serta pupuk pertumbuhan dan produksi, dan mencari kombinasi yang tepat antara dua atau ketiga faktor tersebut. Diharapkan masukan ketiga faktor tersebut merangsang produksi jagung hibrida, sehingga serapan P yang optimal dan produksi jagung yang tinggi. diperoleh Pemberian fosfor maupun pupuk kandang, pada takaran yang dicoba, merangsang pertumbuhan dengan tingkat kontribusi yang hampir sama. Terhadap produksi, masukan fosfor meningkatkan produksi pipilan kering antara 15.62-31.62 persen. masukan pupuk meningkatkan produksi pipilan kering antara 93.48-137.52 persen. kandang Sedangkan Pemberian kapur tidak memberikan pengaruh yang berarti terhadap pertumbuhan dan produksi jagung terutama bila berdiri sendiri. Hal ini disebabkan pH tanah sebelum percobaan agak mendekati optimum untuk pertumbuhan jagung yaitu 5.20 dan kejenuhan Al pun termasuk rendah yaitu 19.47 persen. Akan tetapi terdapat interaksi antara kapur x pupuk kandang, kapur x fosfor dan interaksi ketiganya. Saat taanaman hari dan 10-12 hari, sedangkan kadar P daun tongkol saat Silking meningkat antara 24.22-51.59 persen. keluar bunga jantan dan betina masing-masing dipercepat antara 11-14 Interaksi pupuk kandang x fosfor meningkatkan produksi pipilan kering antara 97-384 persen dan nilai produksi antara 58-260 persen. Hasil pipilan kering masih menunjukkan persamaan yang linier. Kombinasi perlakuan 10.0 ton pupuk kandang/ha baik dengan fosfat maupun tanpa fosfat memberikan produksi jagung pipilan kering di atas 50 ku/ha.
Keyword: Phosphorus fertilizers, Organic fertilizers, Lime

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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