Effect of Grain Pre-Planting Inoculation With Biofertilizers on Morphological Traits and Quantitative Yield of Rice Varieties

In recent years, the importance of producing healthy crops has led to special attention to production methods and applied inputs used. For the purpose, a two-year factorial experiment was conducted a randomized complete block design with three replications at the research site of Rice Research Institute, Rasht, during 2019-2020 to reduce the problems caused by chemical fertilizers and replacing them with biological resources. Experimental factors including eight levels of inoculation: control (without fertilization), Pseudomonas, Azospirillium, Azotobacter, Azospirillium and Pseudomonas, Azotobacter and Pseudomonas, Azotobacter and Azospirillium, Azotobacter, Pseudomonas and Azospirillium, and Hashemi and Gilaneh rice varieties were considered. The results showed that the effect of inoculation and variety on yield components and yield of rice varieties was significant at 5% and 1% probability levels, so that the highest plant height (119.6 cm), number of tillers (12.3), number of panicles per square meter (165.1), number of filled grain (126.3) and minimum number of unfilled grain (7) from the combined treatment of Azotobacter and Azospirillium and Pseudomonas were obtained. Also, application of combined treatment of Azotobacter and Pseudomonas and Azospirillium increased 79.3% and 30.6% of paddy yield and biomass of Hashemi variety and increased 90.2% and 55.9% of paddy yield and biomass of Gilaneh variety compared to the control treatment. According to the results, the application of Azotobacter, Azospirillium and Pseudomonas treatment is recommended due to maintaining and improving some chemical properties of paddy soil and compensating for 47.4% and 56.7% yield of Hashemi and Gilaneh rice varieties compared to chemical fertilizer treatment.