Judul: Efisiensi Penggunaan Nitrogen Pada Padi (Oryza sativa L.)
Abstrak: Nitrogen fertilizer in the form of urea has become a staple for farmers, especially in Indonesia. Consequently, applying such large quantities of urea cannot be avoided. The understanding of nutrient-use efficiency on paddy-field is needed to increase plant productivity and reduce environmental pollution because of the utilization of luxury urea fertilizer. The objective of this research was to quantify the nitrogen-use efficiency (NUE) on paddy-field. This study was conducted in field and green house. The experiments were carried out in the experimental field at the Indonesian Center For Rice Research (ICRR), Subang-West Java and farmer’s field at Bogor– West Java. The N fertilizer applied in ICRR and farmer field were 225 and 612.25 kg urea/ha, established in experimental plots of about 25 m2. The N fertilizer applied in the green house experiment were 200, 300, 400, 500 and 600 kg urea/ha, respectivelly. The result showed that the NUE and N resorption were higher in ICRR than that of in farmer’s field. The green house experiment showed that the NUE and N resorption were higher under 500 kg urea/ha than other treatments. The plant growth, plant biomass, grain yield, NUET, NUEES, ANUE, PNUE dan N resorption were declined with the high availability in nitrogen-pool and increasing in large quantities at certain doses of N fertilizer.
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Judul: Perbedaan keefisienan pemupukan nitrogen pada tanah tergenang dan kadar air kapasitas lapang pada tanaman padi varietas IR-42
Abstrak: Pada budidaya tanaman padi yang intensif pemberian pupuk merupakan salah satu syarat yang tidak dapat ditinggalkan untuk meningkatkan produkai gabah, terutama pada pemakaian varietas padi unggul yang tanggap terhadap pemberian pupuk. Kebanyakan lahan pertanian untuk tanaman padi, baik lahan sawah maupun lahan kering kekurangan nitrogen. Oleh karena itu pemakaian pupuk nitrogen paling banyak dilakukan. Dengan meningkatnya penggunaan pupuk nitrogen perlu dipikirkan keefisienannya dalam rangka penghematan energi. Lahan sawah merupakan area pertanaman padi yang utama, selain sebagian lahan kering untuk pertanaman padi gogo. Penelitian keefisienan pemakaian pupuk nitrogen lebih banyak dilakukan pada pertanaman padi sawah dibandingkan pada padi gogo. Pupuk nitrogen yang biasa digunakan adalah urea dan amonium sulfat. Kebanyakan petani menyukai pemakaian urea yang diproduksi PT Pupuk Sriwijaya karena telah terbukti dapat meningkatkan hasil gabah. Sedangkan urea yang diproduksi PT Pupuk Kujang pada permulaan berproduksi belum banyak dikenal petani, di samping bukti peningkatan hasil gabah belum meyakinkan petani.
Keyword: Oryza;, Rice production;, Fertilization;, Plant nutrition;, Bogor Agricultural University;

Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
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