Judul: Pengaruh Trass dan Kombinasinya dengan Abu Volkan terhadap Sifat Kimia Tanah dan Pertumbuhan Padi pada Tanah Gambut dari Kumpeh, Jambi
Abstrak: Nowadays in Indonesia, the problem of food crisis is still happening, due to increasing of population annually, needs to increase food availability. On the other hand, the productive land for agriculture have limitations because the large land conversion to non-agricultural land. The use of marginal land such as peat is an attempt to overcome the limited productive land for growing rice. Peat soils have low soil fertility level and acid soil reaction in nature. The conditions of peat soils require amelioration to improve soil fertility. The ameliorants that have potential to increase soil fertility are trass and volcanic ash. The purpose of this research was to examine the effects of trass and its combination with volcanic ash on soil chemical properties and rice growth. The research was conducted in a pot experiment using peat soils from Kumpeh, Jambi. Doses of trass as a single factor treatment were 0, 3, 6, and 9% or 0, 90, 180, and 270 gram/pot, and doses of the combination treatments between trass and volcanic ash were 0+7.5, 1.875+5.625, 3.75+3.75, 5.625+1.875, and 7.5+0% or 0+225, 56.25+168.75, 112.5+112.5, 168.75+56.25, and 225+0 grams/pot, the all treatments compared to standard fertilization. The research design was used Completely Randomized Design (CRD). The results showed that giving the trass as a single factor significantly increased the soil pH, Exchangable Al and Mg, available Zn and Mn, plant height, productive tillers, plant biomass, uptake of K, Si, and plant Zn. The combination trass with volcanic ash significantly increased the soil pH, Exchangable Al, total-N, Exchangable Na, available Zn and Mn, plant height, productive tillers, plant biomass, uptake of P, K, Si, and plant Zn. Beside that, combination trass with volcanic ash significantly improved the efficiency of P and K fertilization
Keyword: 

Judul: Pemanfaatan Trass sebagai Pupuk Silika dan Pemberian Dolomit untuk Padi di Tanah Gambut dari Kumpeh, Jambi
Abstrak: High number of population in Indonesia demanding a high amount of rice production to fulfill the food needs as well. Changes of land use from agricultural to non-agricultural land, reducing the ability of rice production. Utilization of peat land for agriculture is an alternative to increase rice production. However, the use of peat land for agriculture will be faced with several constraints such as the low availability of macro and micro nutrients, including deficiency of Mg and Si. Peat soil parent materials derived from organic materials that have a low content of Si. In this study trass and dolomite is used as a source of Si and Mg. This study aimed to know the effect of trass and dolomite as source of Si and Mg on growth and uptake of Si and Mg by paddy, and change the chemical properties of peat. The trial was conducted in the greenhouse and Soil Chemistry and Fertility Laboratory at the Cikabayan Experiments Station and of Department of Soil Science and Land Resources, Faculty of Agriculture, IPB. This trial was done from February to July 2012. Factorial completely randomized design was used in this trial. Trass treatment consist of T0 (without Trass), T1 (2.5% w/w), T2 (5% w/w), T3 (7.5% w/w), whereas the dolomite treatment consist of D1 (1.6 ton/ha), D2 (4.8 tons/ha), D3 (8 tons/ha). The treatment is combination of these two factors resulting 12 combined treatment and 3 repeated in order to get 36 units of trial. Dolomite was significantly affect on plant height, while trass either singly or in combination with dolomite was not. Trass and dolomite singly and in combinations was significantly affect to the number of tillers. Highest plant height and tillers was about 50.1 cm and 10 achieved in T3D3. It was concluded that trass can be used as Si fertilizer. Mg uptake by paddy was increased with increasing doses of dolomite also for Si uptake with increasing of Trass dose. Change of Mg uptake from D1 to D2 and D2 to D3 was 0.26 g/pot and of 1.23 g/pot. Change of Si uptake by paddy from T0 to T1, T2, T3 were 0.34, 11.42 and 43.72 g SiO2/pot respectively. Dolomite was significantly increased of soil pH. Highest and lowest pH values is 5.55 and 4.10 obtained in the treatment T0D3 and T3D1. Dolomite was increased of exchangeable Mg in peat. Change a exchangeable of Mg from D1 to D2 and D3 is 2.29 and 13.76 me/100g respectively. Total of peat SiO2 was increased with increasing dose of Trass. Trass and Dolomite either singly or in combination was significantly affect on availability of SiO2 in peat. Highest available levels of SiO2 was obtained on T3D1 treatment about 61.50 ppm.
Keyword: 

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular