Effect of Azospirillum at different levels of nitrogen on yield of rainfed transplanted rice (Oryza sativa)

An experiment was conducted at Agricultural Research Station (Paddy), Sirsi, during the rainy seasons of 1997 and 1998, to know the efficacy of Azospirillum in conjunction with inorganic nitrogen on yield of rice (Oryza sativa L.). The experiment consisted of 8 treatment combinations of 2 levels of Azospirillum (no Azospirillum and Azospirillum) and 4 levels of nitrogen (0,50,75 and 100% recommended dose of nitrogen). On an average over 2 years, the grain yield of rice increased significantly with Azospirillum treatment (4,957 kg/ha) compared to no-Azospirillum treatment (4,394 kg/ha). Similarly, the grain yield of rice increased significantly with increased levels of nitrogen. The grain yield recorded with Azospirillum + 75% recommended dose of N (5,330 kg/ha) was significantly higher over that of no Azospirillum + 100% recommended dose of N (5,146 kg/ha) but was on a par with that of Azospirillum + 100% recommended dose of N (5,460 kg/ha).