Role of Pseudomonas lini and Brevundimonas nasdae to Enhance Nitrogen Use Efficiency (NUE) and Yield of Oryza sativa L

Abstract

Regular application of synthetic chemicals in rice ecosystem led to loss of nitrogen (N) and affected the native microbial communities. Controlled release fertilizers (CRFs), a solution to poor nitrogen use efficiency (NUE) of urea and associated environmental implications while diminished economic advantages by high CRF use, is major obstacle that still exists. Reviving the diazotrophic native bacteria from rice cultivated locations should be the alternate for bounciness of potential bioinoculants for better performance and yield enhancement. In the present investigation, two potential nitrogen fixing bacteria, Pseudomonas lini GHM32 and Brevundimonas nasdae GHM62 isolated from rice rhizosphere on Rennie medium. These two bacteria were evaluated for yield and NUE in field studies in a randomized block design with treatments, T₁- 100% recommended dose of nitrogen through neem coated urea (RDN), T₂- 50% RDN, T₃- 50% RDN + P. lini GHM32, T₄- 50% RDN + B. nasdae GHM62 and T₅- co-application of both bacterial isolates during Rabi-2020-21 (dry season) and Kharif-2021 (wet season). Experimental results for plant height, chlorophyll, nitrogen content and yield in T₃ were on par T₁. Nitrogen use efficiency indices, such as partial factor productivity (PFP), nitrogen use efficiency (NUE) and nitrogen requirement (NR) of T₃ were at par T₁ throughout the experimental period. This is the first report with field trials on P. lini and B. nasdae as potential diazotrophic bacterial application by reduction in application of inorganic N fertilizer through neem coated urea with a focus on NUE indices and yield improvement of rice.