Judul: Pupuk hayati Azotobacter dan mikrob pelarut fosfat untuk meningkatkan pertumbuhan jagung (Zea mays L.) pada ultisol darmaga
Abstrak: Many efforts had been doing to increase the production of agricultural . One of them was uing the prime variety followed by increased of chemical fertilizer. Utilization of biofertilizer that contained by Azotobacter and Phosphate Solubilizing Microbe were giving more advantages for the users. Except could be increase the readiness of N and P in soils, using Azotobacter and Phosphate Sohbilizing hficrobe inoculants can also reduce the production cost as well as reduced the environmental pollution. The aim of this research was to selected the effective of Azotobacter and Phosphate Solubilizing Microbe which able to improve the growth of maize also uptake nutrition N and P of Ultisols Darmaga. It was isolated from estate palm oil soils of PT. Mitra Ogan and Tea Plantation of PT. Mitra Kerinci, Sumatera Barat. Maize seeds Pionner-12, Ultisols Darmaga, chemical ferlitizer (Urea 41.09 % N, SP-36 16.47 %J P2Os and KC1 50.61 % K2O) were used in this rcsearch.
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Judul: Pertumbuhan dan Potensi Produksi Tanaman Padi dan Jagung Pada Tanah Podsolik Merah Kuning yang Diperkaya Pupuk Hayati
Abstrak: Yellow Red Podzolic soil (YRP) is one of the low fertility soil. The fertility of YRP soil could be increased using the biofertilizer because it can improve soil fertility, plant growth and yield. The objective of this study were to analyze the growth of plant and production potential of rice and maize on YRP soil, which enriched by biofertilizer. The biofertilizer used in this research were Plant Growth Promoting Rhizobacteria (PGPR) (Azotobacter sp., Azospirillum sp., Bacillus subtilis and Pseudomonas beteli), arbuscular mycorrihzal fungus (AMF) that was Glomus manihotis, endophytic that was Aspergillus niger, and an anorganic fertilizer used NPK Pelangi. The experiment used Complete Randomized Design with ten levels of treatment for rice and thirteen levels of treatment for maize, all in five replication. Rice cultivated on a pot which filled by 8 kg of soil. Maize cultivated on a poliybag (40 cm x 40 cm) filled by 10 kg of soil. The result showed that the aplication of biofertilizer (PGPR + endophytic) with reduced NPK up to 50% was not different than control (NPK 100% + compost without PGPR) to support plant growth and yield of rice. While maize showed that the aplication of biofertilizer (PGPR + endophytic + AMF) with reduced NPK up to 50% showed significantly increase height of plant, round of stem and length of ear than control (NPK 100% + compost without PGPR). This research suggest that enriched of podzol soil with biofertilizer could reduce application of anorganic fertilizer (NPK) up to 50% of recomendation doses.
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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