Grain Filling Rate and Nutrient Uptake of Rice as Influenced by Bacterial Inoculation

Abstract

A pot experiment was conducted in the presence and absence of nitrogen in order to evaluate the influence of Azospirillum lipoferum on grain filling rate and nutrient uptake of rice. Soil samples were collected from the Dhamrai series of Young Brahmaputra Floodplain soil. The bacterial strain Azospirllum lipoferum was isolated from the rice rhizosphere of the same soil. Each pot contained 10 kg well sieved soil and four hills of rice plant in the each pot were transplanted. In inoculated treatments, each rice grain was treated with 10⁶ cells of Azospirillum lipoferum before being sown in the seedbed. Once more each seeding was treated at least 10⁶ cells of bacteria before transplantation. Nitrogen as urea was applied at the rate of zero nitrogen (0 kg/h), 45 ky/h and 90 kg/h. Phosphorus, potassium and sulphur were applied at the rate of 60 kg/h, 40 kg/h and 10 kg/h, respectively as the basal doses. The grain filling rate, uptake of N, P, K and rice yield increased remarkably due to inoculation with Azospirillum lipoferum.