Application of Pseudomonas mosselii PR5 Enables Fertilizer Reduction in Rice While Maintaining Yield, Grain Quality,...

The use of inorganic fertilizers in rice farming has led to increased production costs, reduced nutritional value, and it results in major ecological damage. Harnessing plant growth-promoting rhizobacteria (PGPR) offers a promising eco-friendly alternative to conventional fertilization strategies. This study evaluates the potential of Pseudomonas mosselii PR5 as a bioinoculant to enhance rice growth under reduced fertilizer inputs in a pot experiment. Two application methods, seed priming (B1) and seed priming combined with bacterial culture filtrate (BCF) foliar spray (B2), were evaluated across four fertilizer regimes: 0% (F0), 50% (F1), 75% (F2), and 100% (F3) of the recommended dose of fertilizer (RDF). Application of PR5 significantly enhanced rice growth, yield, and yield-related traits across all fertilizer levels and application methods. At 100% RDF, the combination of seed priming with foliar application of PR5 resulted in marked increases in plant height (4.3%), biomass (64.4%), chlorophyll content (47.4%), grain yield (48%), and benefit-cost ratio (67.6%) compared to the 100% RDF alone. Notably, the combined PR5 application at 75% RDF showed similar agronomic performance and yield as in the 100% RDF treatment, indicating 25% less fertilizer requirement for maintaining crop profitability. Multivariate analysis also confirmed a strong association of grain and soil nutrients with the combined application of PR5 at 75% and 100% RDF. PR5 application also boosted both grain nutrient content and post-harvest soil nutrient levels. Thus, this research showed that PR5 application increased crop productivity while improving grain nutritional quality and lowering the need for chemical fertilizers towards sustainable agriculture.