Judul: Pengaruh Kadar Air dan Pemberian Pupuk terhadap Dekomposisi Bahan Gambut
Abstrak: Peat land has often been used for large scale farming and plantation. Thus the technology on its utility has been improved and shows a bright prospect. However, the use of those technology upon the peat land has received many critics. Many scientists suggest that the decreasing of ground water levels in peat land will cause the increase of CO2 emission; the lower the groundwater surface, the more emission will be. However, this theory is only based on chemistry and physics reactions, while in fact the decomposition process is determined by biochemical reactions where microbes hold an important role. The objective of this research is to know the effect of water content combined with the addition of fertilizer on the peat decomposition and its composing materials based on its respirations. The respiration was measured by Jar Method. Respiration measurement was done every 10 days until the level of respiration rate was constant. The result showed that 2 times water holding at field capacity (WHFC) treatment has the highest respiration value as compared with 1 times WHFC and 0.5 times WHFC. The addition of urea fertilizer whether alone or combined with SP-36 has an effect to the value of the respiration. The addition of litters on sieved peat (GS) or the sieved peat combined with woody materials (GBS) also showed high respirations value. The high value of respiration was affected by the population of bacteria and fungi. This is supported by suitable environment and adequate food supply. Result of final analysis after incubation showed C/N and C/P ratio may not figured the rate of decomposition.
Keyword: water content, respiration, peat composing materials, peat decomposition

Judul: Pengaruh Dosis Pupuk Urea dan SP-36 terhadap Dekomposisi Bahan Gambut
Abstrak: Pemanfaatan lahan gambut di Indonesia saat ini meningkat seiring dengan semakin berkurangnya lahan produktif untuk kegiatan pertanian. Namun perkembangan kegiatan tersebut terhambat karena isu pembukaan dan pemanfaatan lahan gambut dapat meningkatkan emisi Gas Rumah Kaca (GRK). Penurunan muka air tanah dan pemberian pupuk pada lahan gambut seringkali dikorelasikan langsung dengan kehilangan gambut akibat peningkatan dekomposisi gambut yang melepaskan CO2 ke atmosfer. Disamping itu, pentingnya peranan mikrob seringkali tidak dipertimbangkan padahal peranan mikrob dalam dekomposisi bahan gambut sangat vital dalam hal total aktivitasnya. Aktivitas mikrob dipengaruhi oleh berbagai faktor seperti nutrisi, pH, kelembaban, dan kandungan senyawa beracun pada lahan gambut. Penelitian ini dilakukan untuk mengetahui pengaruh unsur hara N dan P terhadap aktivitas mikrob dan dekomposisi bahan gambut berkaitan dengan emisi CO2 yang dihasilkan. Aktivitas mikrob dicerminkan dari populasi bakteri dan fungi (metode cawan tuang) dan serta kaitannya dengan respirasi tanah (metode stoples). Hasil penelitian menunjukkan respirasi tertinggi berasal dari serasah. Hal ini disebabkan pada serasah daun Acacia crassicarpa masih terdapat banyak nutrisi dan sumber energi yang dapat dimanfaatkan oleh mikrob sehingga aktivitas mikrob pun meningkat. Hal ini menandakan bahwa kontribusi CO2 yang tinggi dihasilkan dari dekomposisi serasah dibandingkan dengan yang dihasilkan dari dekomposisi bahan gambut. Aktivitas mikrob dan dekomposisi bahan gambut tertinggi ditunjukkan pada penambahan pupuk N yang dilihat dari populasi mikrob dan respirasi yang lebih tinggi dibandingkan penggunaan pupuk N dengan pupuk P. Hasil ini menunjukkan unsur hara N yang menjadi faktor pembatas dari aktivitas mikrob (tanpa mengabaikan peran unsur hara N dan P untuk mikrob) sebagai sumber hara dan pertumbuhannya.
Keyword: aktivitas mikrob, dekomposisi bahan gambut, pupuk, respirasi

Judul: Mitochondrial DNA Gene Organization and Phylogenetic Relationship of Naja siamensis
Abstrak: Naja siamensis is one of Asiatic cobra in the Family of Elapidae, known as a cryptic snake. It has many morphological variations that lead to misidentification. Misidentification can cause the wrong concept in developing antivenom types due to high snakebite cases occur in Thailand. Thus, an accurate species identification using a molecular approach is crucially required. Mitochondrial DNA has been used widely in snake molecular studies. These studies were aimed to determine the arrangement of the N. siamensis partial mitochondrial genes using reptile-oriented primers and to reveal the phylogenetic relationship among other species of Asian cobra. DNA extraction was carried out based on the standard DNA salting-out protocol and was conducted by bioinformatics analysis using BLASTn and MEGA 6 software. Gene annotation was performed against N. kaouthia complete genome. A total of 3121 bp of N. siamensis mtDNA genes were sequenced consisting of partial of six regions: 16S rRNA, ND1, tRNA-Ile, CRII region, tRNA-Leu, tRNA-Gln, and COI genes. The mtDNA gene organization of N. siamensis was predicted to has a similar pattern with the common Elapidae mtDNA gene organization. This study showed that there is a monophyletic form in Naja genus and N. kaouthia is the closest species with N. siamensis based on partial 16S rRNA and ND1 gene.
Keyword: 16S rRNA, Elapidae, ND1, phylogenetic relationship