Judul: Aplikasi pupuk anorganik dan pupuk organik hayati pada budidaya padi sri (System of Rice Intensification)
Abstrak: Excessive use of inorganic fertilizers mainly NPK cause soil degradation, environment pollution, lower yield decreased production, and reduce soil biological activity. System of rice intensification is one method of rice cultivation. SRI main principles are seed transplanting at young age (7-11 days old), transplanting use single seedling methode, seedlings at wide plant spacing ≥ 25x25 cm, intermittent irrigation and field conditions are not flooded, and reduction of chemical fertilizers used and replaced by organic fertilizer. This research was conducted from April 2010 to January 2011 in Situgede Village, West Bogor District, Bogor. The research design used split plot randomized complete block design with three blocks. Two rice cultivation system as the main plot and five combinations of fertilizer application as sub plot. The result showed that the maximum number of tillers on SRI method higher at 25,8 tillers/hill or an increase of 64,33% compared with conventional methods. Wet and dry shoot weight of wet and dry weight of root is greater in successive SRI method of 13,3%, 19,1%, 18,4% and 41,8% compared with the conventional method. The number of productive tillers, grain number/panicle, 1000 grains weight, root wet weight and dry grain at SRI method was higher than those in conventional method respectively 58,6%, 37,0%, 2,5%, 25,1% and 32,6%. Uptake of N and P in the SRI method higher at 72,0% and 100% compared to conventional method. Application 50% inorganic fertilizer + 200 kg bio-organic fertilizer, producing more fresh weight biomass, plant dry weight, wet weight and dry weight, number of productive tillers, 1000 grain weight respectively 13,9%, 42,0 %, 49,8%, 74,0%, 10,7% and 2,48% compared with the dosage recommendations dose or 100% inorganic fertilizer. N, P and K uptake at 50% inorganic fertilizer + 200 kg of bio-organic fertilizer treatment higher (55,6%, 66,7% and 46,2%) than the foal recommendation dose of inorganic fertilizer. Bio-organic fertilizer can be used as substitute of NPK fertilizer.
Keyword: 

Judul: Pupuk hayati terhadap pertumbuhan dan produksi padi sawah (Oryza stiva L.) pada teknik budidaya System of Rice Intensification (SRI)
Abstrak: research was conducted to determine the effect of biofertilizer on the growth and yield of lowland rice in System of Rice Intensification cultivation. Experiment used Split Plot Randomized Block Design. The main plot consists of two rice cultivation (System of Rice Intensification and Integrated Crop Management). There are seven rate of combination of fertilization treatments on each subplot (without NPK fertilizer, biofertilizer and organic fertilizer; 100% NPK dose; 100% NPK dose + biofertilizer; 50% NPK dose + organic fertilizer + biofertilizer; 50% NPK dose + biofertilizer; 50% NPK dose; and biofertilizer). The results showed that reduction dose of NPK fertilizer up to 50% on System of Rice Intensification can increase rice yield either added biofertilizer or without biofertilizer. On the cultivation of Integrated Crop Management, dose reduction of NPK fertilizer up to 50%, decrease rice yields eventhough added biofertilizer. The application of System of Rice Intensification on the rice cultivation produced the plant height shorter significantly, number of productive tillers and wet grain yield more significant than the Integrated Crop Management although dry grain yield was not significantly different
Keyword: 

Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf