Judul: Pengaruh Nitrogen dan Rhizobium sp. terhadap Pertumbuhan dan Produksi Kedelai Hitam (Glycine soja) pada Budidaya Jenuh Air di Lahan Pasang Surut
Abstrak: This research aims to determine the optimum concentration of nitrogen fertilizer and influence of Rhizobium sp. as inoculant on the growth and production of black soybeans. The experiment was conducted in the tidal swamps of Banyu Urip village, sub District of Tanjung Lago, Banyuasin District, Palembang, South Sumatera Province from May to September 2013. This research used split plot design with three replications. The concentration of nitrogen as the main plot consisted of 0, 5, 10, and 15 g Urea l-1 water and the Rhizobium sp. as a subplot consist of plus Rhizobium sp. and without Rhizobium sp. Saturated soil culture (SSC) technique was used to support the cultivation of soybeans in tidal swamps. The results showed that the effect of the nitrogen concentration of 15 g Urea l-1 water tends to produce the highest productivity up to 3.775 ton ha-1 and more profitable economically. This is supported by leaf N content to be high at 15 g Urea l-1 water up to 4.89%. Addition of Rhizobium sp. is effective enough increase growth and production although not significantly different. The results also indicate that there is interaction of the two treatments on number of leaves at 4 WAP, then there is no interaction was found on the other variables.
Keyword: tidal swamps, saturated soil culture, Rhizobium sp, nitrogen, black soybean

Judul: Pengaruh Pemberian Abu Sekam, P, dan K terhadap Pertumbuhan dan Produksi Kedelai Hitam pada Budi Daya Jenuh Air di Lahan Pasang Surut
Abstrak: The experiment was carried out to evaluate the effect of husk ash, phosphorus, and potassium fertilizer on the growth and production of black soybean under saturated soil culture on tidal swamps. The experiment was conducted in the tidal swamps of South Sumatera Province, Banyu Urip village, sub District of Tanjung Lago, Banyuasin District, Palembang since April to August 2014. This experiment was using Randomize Complete Block Design with three replications. The concentration of husk ash as the first factor consist of 0, 1 000, 2 000, 3 000 kg ha-1, the concentration of phosphorus fertilizer as the second factor consist of 36 and 72 kg ha-1 P2O5, and the concentration of potassium fertilizer as the third factor consist of 30 and 60 kg ha-1 K2O. Saturated soil culture (SSC) technique was used to support the cultivation of soybeans in tidal swamps. The results showed that the effect of husk ash concentration, interactions of husk ash and phosphorus fertilization, interaction of husk ash and potassium fertilization and interaction of husk ash, phosphorus and potassium fertilization increased the ammount of trifoliat leaves. The optimum combination of 1.26 ton ha-1 husk ash, 36 kg ha-1 P2O5 phosphorus fertilization and 30 kg ha- 1K2O potassium fertilization gave the highest productivity by 4.21 ton ha-1and decreased the dose of Phosphorus and Potassium fertilizer
Keyword: Bogor Agricultural University (IPB), under saturated soil culture, potassium, phosphorus, husk ash, black soybean

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