ABSTRACT: A research was aimed to decribe the effect from the population density of nitrogen-fixing bacteria of Azospirillum sp. to soybean (Glycine max L. Merr.) vegetative growth. Research was conducted at the Laboratory of Agroecology and Garden Experiment of Agriculture Faculty in Sultan Ageng Tirtayasa University starting from August until October 2013. This research used factor Randomized Completely Block Design (RCBD). The factor was consisted of 6 levels which were without giving Azospirillum sp. (AZ0), population density of Azospirillum sp. 102 cfu/ml (AZ1), 104 cfu/ml (AZ2), 106 cfu/ml (AZ3), 108 cfu/ml (AZ4), 1010 cfu/ml (AZ5). Each one was repeated 4 times with further test of Duncan’s Multiple Range Test 5%. The observation was consisted of several parameters, that were plant height, quantity of leaves, root length, leaf area, crown dry weight and root dry weight. The results showed the two isolates founded of bacteria Azospirillum sp. who was ability to fixating a nitrogen from soybean rhizosphere soil with each given code Azp1 and Azp2. The population density of Azospirillum sp. also showed significantly different at 3, 4 and 5 weeks after planting and high significantly different at 6 weeks after planting of plant height parameters of soybean plants.
Penulis: Dewi Firnia, Kartina AM, Cori Damayanti
Kode Jurnal: jppertaniandd140746