Judul: Infiltration Capacity and Aggregate Stability on Land with Slot Tillage System Equipped Bund Terrace Variants and their Relationship with Surface Runoff and Erosion
Abstrak: Proses terjadinya erosi sangat berkaitan dengan aliran permukaan. Aliran permukaan mengakibatkan partikel-partikel tanah di bagian permukaan terlepas dan terangkut ke tempat lain. Besarnya aliran permukaan dan erosi dipengaruhi oleh banyak faktor, diantaranya adalah stabilitas agregat tanah dan kapasitas infiltrasi tanah. Oleh karena itu, pengendalian aliran permukaan dan erosi dapat diarahkan pada perbaikan stabilitas agregat dan kapasitas infiltrasi tanah, antara lain dengan pengolahan tanah secara slot till dan berbagai varian teras gulud. Penelitian yang bertujuan mengetahui pengaruh sistem olah tanah slot till dengan berbagai varian teras gulud terhadap kapasitas infiltrasi dan stabilitas agregat tanah serta hubungannya dengan aliran permukaan dan erosi dilakukan di Kebun Pendidikan Cikabayan IPB. Penelitian menggunakan Rancangan Acak Lengkap (RAL) terdiri dari lima perlakuan, masing-masing dengan tiga kali ulangan, yaitu P1) kontrol, P2) slot till, P3) slot till dengan teras gulud, P4) slot till dengan teras gulud diberi mulsa organik pada saluran terasnya, P5) slot till dengan teras gulud diberi mulsa organik dan dibuat Lubang Resapan Biopori (LRB) pada saluran terasnya. Pengukuran infiltrasi dilakukan menggunakan double ring infiltrometer dan stabilitas agregat diukur menggunakan ayakan kering dan basah. Hasil pengamatan menunjukkan bahwa perlakuan slot till dengan berbagai varian teras gulud dapat meningkatkan kapasitas infiltrasi dan stabilitas agregat serta menurunkan aliran permukaan dan erosi. Perlakuan slot till dengan teras gulud serta mulsa organik pada saluran dan LRB (P5) memberikan pengaruh yang lebih signifikan terhadap kapasitas infiltrasi dan stabilitas agregat tanah dibandingkan dengan perlakuan lainnya. Nilai kapasitas infiltrasi dan stabilitas agregat pada bidang olah berkorelasi nyata terhadap aliran permukaan dan erosi., The process of erosion is closely related to surface runoff. Surface runoff causes soil particles on the surface to be detached and transported to other locations. The amount of surface runoff and erosion is influenced by many factors, including soil aggregate stability and soil infiltration capacity. Controlling surface run off and erosion may therefore, be directed to improving the two soil characteristics which can be done by practicing slot tillage in combination with various bund terraces. Research aimed at determining the effect of a slot tillage system combined with various bund terrace on infiltration capacity and soil aggregate stability and their relationship to surface runoff and erosion was conducted at IPB's Cikabayan Education Farm. The research used a completely randomized design consisting of five treatments with three replications, namely P1) control, P2) slot till, P3) slot till with bund terrace, P4) slot till with bund terrace with organic mulch applied on the trench, P5) slot till with bund terrace with organic mulch and biopore infiltration pits on the trench. Infiltration was measured using a double ring infiltrometer and aggregate stability was measured using dry and wet sieves. The results showed that slot till treatment with different variants of bund terrace can increase infiltration capacity and aggregate stability and reduce surface runoff and erosion. The slot till treatment with bund terrace with organic mulch application and biopore infiltration pits on the trench (P5) gave a more significant effect on soil aggregate stability and soil infiltration capacity compared to other treatments. The value of infiltration capacity and aggregate stability in cultivated field was significantly
Keyword: lubang resapan biopori, mulsa organik, sifat fisik tanah, sistem olah tanah, saluran

Judul: Soil Shear Strength Due to Slot Till Processing and Various Gulud Terrace Treatments
Abstrak: Pengolahan dan pengelolaan tanah yang kurang tepat merupakan salah satu penyebab terjadinya pemadatan pada suatu lahan sedangkan kemiringan lereng yang curam merupakan salah satu penyebab terjadinya erosi. Tanah yang padat akan sulit ditembus oleh akar dan cenderung mempunyai kekuatan geser tanah yang tinggi. Erosi dapat terjadi pada tanah yang padat akibat penurunan kemampuan tanah dalam menyerap air terutama pada area berlereng dengan curah hujan tinggi. Salah satu cara untuk mencegah terjadinya erosi adalah dengan menerapkan teknik konservasi seperti pembuatan slot till dan teras gulud. Penerapan teknik slot till dan teras gulud diharapkan dapat mengurangi laju erosi tanah dan memperbaiki sifat fisik tanah sehingga pertumbuhan tanaman tidak terganggu. Penelitian yang bertujuan untuk mengetahui pengaruh pengolahan secara slot till dan berbagai perlakuan teras gulud yang dikombinasikan dengan penambahan mulsa organik dan lubang resapan biopori (LRB) terhadap kekuatan geser tanah serta sifat-sifat fisik tanah dilaksanakan di Petak Erosi Kebun Pendidikan Cikabayan IPB. Penelitian dilakukan menggunakan Rancangan Acak Lengkap (RAL) dengan 5 perlakuan, yaitu perlakuan berupa penanaman menurut kontur dan baris tanaman yang dibuat gundukan sebagai kontrol (P1), slot till (P2), slot till dan guludan bersaluran (P3), slot till dan guludan bersaluran yang diberi mulsa (P4), slot till dan guludan bersaluran yang ditambahkan mulsa serta LRB (P5); setiap perlakuan dilakukan ulangan sebanyak 3 kali. Pengukuran kekuatan geser tanah dilakukan pada 3 kondisi kadar air (rendah, sedang, tinggi) menggunakan alat TORVANE pocket shearmeter dan analisis sifat fisik serta kimia yang berkaitan dengan kekuatan geser tanah dilakukan di laboratorium. Hasil penelitian menunjukkan bahwa kekuatan geser tanah pada lahan dengan perlakuan P1, P2, dan P3 cenderung lebih tinggi dibandingkan dengan P4, dan P5. Kekuatan geser terendah terjadi pada perlakuan dengan penambahan mulsa organik pada saluran (P4) dan disertai LRB (P5). Bobot isi tanah dan ruang pori total berkorelasi positif terhadap kekuatan geser tanah, sedangkan kadar C-organik (bahan organik) berkorelasi negatif terhadap kekuatan geser tanah., Improper soil tillage and management is one of the causes of land compaction while steep slope is one of the causes of erosion. Compacted soil causes roots to have difficulty to penetrate and tends to have higher soil shear strength. Erosion can occurre on compacted soils due to the decrease of the soil’s ability to absorb water especially in a steep slope area with high rainfall. One of the methods to prevent erosion is by applying conservation techniques such as slot tilling and gulud terrace. The application of slot tillage and gulud terrace techniques is expected to reduce the rate of soil erosion and improve soil physical properties so that plant growth is not disturbed. Research aimed at determining the effect of slot tillage processing and various gulud terrace treatment in the form of the addition of organic mulch and biopore infiltration pits on soil shear strength and soil physical properties was conducted at the Erotion Plots of the Cikabayan Experimental Farm of IPB. The research used a Completely Randomized Design (CRD) consisting of five treatments namely control (P1), Slot Tillage (P2), Slot Tillage with terrace bund (P3), Slot Tillage with terrace bund equipped with organic mulch on the trench (P4), Slot Tillage with terrace
Keyword: Gulud Terrace, slot tillage, soil shear strength, physical properties

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