Judul: Isolasi dan seleksi mikrob tanah yang menguntungkan serta pengaruhnya terhadap tanaman kangkung [Ipomoea reptans Poir]
Abstrak: Kesuburan tanah merupakan salah satu kunci penting dalam mencapai keberhasilan produktivitas pertanian. Pemakaian pupuk sintetik secara intensif merupakan kegiatan yang umumnya dilakukan petani untuk meningkatkan kesuburan tanah. Namun hal itu dapat mengakibatkan terjadinya kerusakan lahan dan pencemaran lingkungan. Oleh karena itu, seiring dengan meningkatnya kesadaran masyarakat mengenai pentingnya menjaga kelestarian lingkungan dan kesehatan, maka berbagai alternatif teknologi maju yang ramah lingkungan diusahakan di bidang pertanian. Salah satu teknologi maju yang dimanfaatkan adalah penggunaan pupuk mikrob. Pupuk mikrob mengandung mikrob yang menguntungkan yang berperan dalam menghancurkan limbah organik, membantu penyerapan unsur hara, memfiksasi nitrogen secara biologis, meningkatkan pelarutan fosfat, merangsang pertumbuhan tanaman dan biokontrol patogen. Meskipun demikian, eksplorasi maupun paparan mengenai berbagai potensi mikrob tanah yang menguntungkan bagi pertanian tersebut tergolong masih sangat sedikit, apabila dibandingkan dengan keanekaragaman hayati (biodiversity) mikrob di Indonesia. Oleh karena itu, penelitian ini bertujuan untuk melakukan eksplorasi terhadap mikrob tanah untuk mendapatkan isolat-isolat mikrob tanah yang menguntungkan, dan menguji pengaruh pemberian isolat tersebut terhadap tanaman kangkung (Ipomoea reptans Poir).
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Judul: Isolasi dan seleksi mikrob tanah yang menguntungkan serta pengaruhnya terhadap tanaman caisin (Brassica parachinensis)
Abstrak: Indonesia has soil that is very potential to be explored its microbe. Unfortunately the researchs in regards to the total, type, and the diversity of soil microbe are still rare. Hence the major part of soil miciobe is beneficial to the plant growth and it is required in the sustainability of nutrient cycling process in the nature. LnocuIation of soil microbe is expected to assist enhancing the availability of soiI organic matter and at the end will improve plant growth. This research was aimed to get the best microbe isolates and to study their impact on the growing of caisin plant (Brnssicn pnvnchirzensis). Soil samples for microbe isolation were taken fiom two locations namely Cugenaltg and Cikabayan. There were ten best isolates namely: two isolates of phosphate solubilizing bacteria (BF63 and BF223), two isolates of phosphate solubilizing fungi fFF23 and FF51), two isolates of Pseudomonas (P83 and PI 13), and four isolates of ceIlulose degradation microbe (S31, $33, S52, and S133). All of the ten isolates plus one comparison isolate and co~~txoaft the end were inoculated to the caisin plant. This resemch used Con~plete Random Design (RAL) with 24 treatrneilts, substantially microbe treatment with the full fertilizer dosage and microbe treatment with half fertilizer dosage. The entire treatments were repeated thee times so these were 72 experimental units.
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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