Judul: Pengaruh Kaptan, Trass, Dan Pupuk Fosfor Terhadap Kedelai Varietas Orba Pada Podsolik Jasinga
Abstrak: Soybean is one of commodities that is consumed in large quantities by Indonesian peoples. In the year of 2009, total of soybean was needed by Indonesian about 2.2 million tons. At that time the local soybean production was about 974,512 tons, so that the lack of soybean production should be added by imports. One of the main problems of low soybean yield in Indonesia is low of soil fertility. Additional of ameliorant matter such as agricultural lime and Trass, and fertilization are the way to solve the problem of soil fertility. In this case, agricultural lime and Trass act as liming matterial, and Trass also potentially as a source of silicate nutrient for plants. The objectives of this study to know the influence of agricultural lime, Trass and phosphorus fertilizers on soil chemical properties and the growth, nutrient uptake, and yield of soybean in Jasinga’s Podzolic. The experiment was conducted at the Cikabayan Experimental Station and analysis of soil and plant tissue in Soil Chemistry and Fertility Laboratory, Faculty of Agriculture, Bogor Agricultural University. This experiment was conducted in a Completely Randomized Design (CRD) with two factors, the first factor was dosages of ameliorant matter (agricultural lime/Trass) (without amelioran, 1x exch-Al, 2 x exch-Al) and the second factor was dosages of phosphorus fertilizer (without P, 250 kg / ha, 500 kg / ha), and each treatment was replicated three times. The results of the study showed that agricultural lime treatment increased soil pH and decreased exch-Al; while Trass treatment was not significantly affect on pH and exch-Al. Agricultural lime, Trass and P fertilizer treatments increased available soil P. The available P and exchangeable Ca of soil with the treatment of agricultural lime was higher than treatment of Trass. In both ameliorant experiment, P fertilizer treatment significantly increased plant height and leaf number, but in agricultural lime treatment, the increase of plant height and leaf number greater than Trass treatment. Agricultural lime treatment significantly affected the leaf number, whereas Trass was not. All treatments did not significantly affect the fresh and dry weight of stover. While, phosphorus fertilizer treatment significantly increased the fresh and dry weight of roots in Trass experiment . Phosphorus treatment significantly increased of P uptake of soybean in both ameliorant wether agricultural lime or Trass. Agricultural lime treatment significantly increased the Ca uptake of soybeans, while was not for Trass treatment. Trass treatment increased uptake of SiO2, while agricultural lime was relatively small. Increasing dosage of agricultural lime significantly increased the weight of pods and seeds, but Trass dosages was not affected. The average weight of pods and seeds of soybeans on agricultural lime experiment was higher than Trass experiment.
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Judul: Pengaruh pemupukan fosfor dan kalsium terhadap serapan hara dan produktivitas dua genotipe kedelai pada budidaya kering dan jenuh air
Abstrak: The objectives of this research were to study the effect rates of P and Ca fertilizers on productivity and nutrient uptake of two soybean genotypes in dry culture and saturated soil culture, and to compare the nutrient uptake and productivity in soybean dry culture with saturated soil culture. The experimental design was split split plot with three factors i.e. phosphorus, calcium and genotype planted in dry culture and saturated soil culture. Dry culture with phosphorus fertilizer application (72 kg P2O5/ha) increases the number of filled pods and grain weight per plot. Number of pods of Tanggamus variety was greater than Anjasmoro variety. Liming had no effect on productivity. Path analysis showed that largest direct effect to grain weight were plant height and leaf weight. Increased rate of P and Ca fertilizer increased the uptake of P and Ca, but variety Tanggamus is more responsive than variety Anjasmoro. Saturated soil culture with phosphorus fertilizer (72 kg P2O5/ha) and lime (1 ton/ha) increased the number of pods content and grain weight per plot. Variety Tanggamus had higher number of pods and grain weight per plot than variety Anjasmoro. Interaction of phosphorus fertilizer 72 kg P2O5/ha with lime 1 ton/ha increased grain weight per plot. Largest direct effect on increasing grain weight is plant height and the number of branches. Phosphorus application (72 kg P2O5/ha) and liming (1 ton/ha) also give highest uptake of P and Ca. Saturated soil culture technology can be applied to increase soybean nutrient uptake and productivity than dry culture.
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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