Judul: Aplikasi Inokulan Bradyrhizobium japonicum Pada Tanaman Kedelai Varietas Wilis di Tanah Asam
Abstrak: Kedelai tidak memiliki wilayah produksi yang permanen di Indonesia, sehingga mudah terdesak oleh tanaman lain yang bernilai ekonomi lebih tinggi. Produksi kedelai memerlukan tambahan area tanam kedelai. Area perluasan tersebut antara lain di lahan dengan produktivitas rendah, seperti tanah asam dengan kandungan Al yang tinggi. Bradyrhizobium japonicum (BJ) merupakan bakteri penambat nitrogen yang dapat memacu pertumbuhan dan produksi kedelai. Penelitian ini bertujuan mempelajari pengaruh inokulan B. japonicum toleran asam-Aluminium terhadap pertumbuhan dan produksi kedelai varietas Wilis yang ditanam pada tanah asam. Penelitian dilakukan di lahan Cikabayan IPB Darmaga, Bogor. Perlakuan terdiri atas tanah asam sebagai kontrol; BJ 11 (19) hasil mutagenesis transposon; BJ 11 (wt) tipe liar; BJ 11(19) + kompos; BJ 11 (wt) + kompos, dan kompos tanpa Bradyrhizobium japonicum. Hasil yang diperoleh menunjukkan bahwa perlakuan BJ 11(wt) + kompos dapat meningkatan tinggi tanaman dan jumlah biji dibandingkan dengan kedelai tanpa perlakuan Bradyrhizobium japonicum. Kata kunci: Bradyrhizobium japonicum, Kedelai varietas Wilis, Tanah Asam, Kompos, Mutagenesis transposon
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Judul: Pertumbuhan dan produksi kedelai Wilis yang diinokulasi dengan Bradyrhizobium japonicum dan pemberian pupuk kimia di tanah asam
Abstrak: Soybean (Glycine max) is an important agricultural commodity that has a high economic value. The increasing in soybean consumption should be fulfilled with the expansion of agricultural land in low productivity areas and increasing production. This may be done by using marginal land and increasing production with fertilizer application. Bradyrhizobium japonicum is a N-fixing bacteria can promote soybean growth with its symbiosis. Two isolates of B. japonicum (BJ 11(19) and BJ 11(wt)) were used as inoculants for soybean. BJ 11(19) was resulted by transposon mutagenesis, whereas BJ 11(wt) was wild type bacteria. The objective of this study was to investigate growth and production of soybean var. Wilis inoculated by B. japonicum and fertilizer application in the acid soil. Soybean were inoculated with BJ 11(19) and BJ 11(wt) combined with compost and N fertilizer. The results showed that application of B. japonicum, compost, and N fertilizer significantly affected the plant height, wet and dry weight of shoots and roots, nodules number, wet and dry weight of nodules, nitrogenase activity, number of pod and seed, seed weight, weight of 100 seeds, and N concentration of seeds.
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Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology