Document Type : Original Article


Department of Agronomy and Plant Breeding, Rasht Branch, Islamic Azad University, Rasht, Iran


A field experiment was conducted at Rice Research Station of Tonekabon, Iran, to determine the effect of seed inoculation with plant growth-promotingrhizobacteria on rice grain yield and yield components under different nitrogen (N) rates. The experimental design was a Randomized Complete Block with factorial arrangement and three replicates. Factors included seed inoculation with plant growth-promoting rhizobacteria [control (un-inoculated), seed inoculation with Azospirillum lipoferum, seed inoculation with Azotobacter chroococcum, and seed inoculation with a combination of A. lipoferumand A. chroococcum] and N rates (100%, 75%, and 50% of recommended nitrogen rates, i.e. 100, 75 and 50 kg N ha-1, respectively). Results showed that the highest grain yield (7875 kg ha-1) was recorded for plants inoculated with a combination of A. lipoferumand A. chroococcum, while the lowest one was recorded for un-inoculated control plants. Moreover, rice grain yield, panicle number per m2, grain number per panicle, and 1000-grain weight increased by 9%, 9%, 18%, and 6%, respectively, as N fertilizer rate increased from 50 to 100 kg ha-1. The highest grain yield (7875 kg ha-1) was obtained when N was applied at the rate of 75 kg ha-1to seeds inoculated with a combination of A. lipoferumand A. chroococcum.


Main Subjects

Araújo, A.E.S, Baldani, V.L.D, Galisa, P.S., Pereira, J.A., & Baldani, J.I. (2013). Response of traditional upland rice varieties to inoculation with selected diazotrophic bacteria isolated from rice cropped at the Northeast region of Brazil. Applied Soil Ecology, 64, 49–55.
Balandreau, J. (2002). The spermosphere model to select for plant growth promoting rhizobacteria. Biofertilisers in Action. Rural Industries Research and Development Corporation, Canberra, 55-63.
Belimov, A.A., Kojemiakov, A.P., & Chuvarliyeva, C.V. (1995). Interaction between barley and mixed cultures of nitrogen fixing and phosphate-solubilizing bacteria. Plant and Soil, 173(1), 29–37.
Choudhury, A.T.M.A. & Kennedy, I.R. (2004). Prospects and potentials for systems of biological nitrogen fixation in sustainable rice production. Biology and Fertility of Soils, 39(4), 219–227.
Choudhury, A.T.M.A. & Kennedy, I.R. (2005). Nitrogen fertilizer losses from rice soils and control of  environment pollution problems. Communications in Soil Science and Plant Analysis,       36(11-12), 1625–1639.
Choudhury, A.T.M.A. & Khanif, Y.M. (2004). Effects of nitrogen and copper fertilization on rice yield and fertilizer nitrogen efficiency: a 15N tracer study. Pakistan Journal of Science and Industrial Research, 47(1), 50–55.
Elbadry, M., El-Bassel, A., & Elbanna, K. (1999). Occurrence and dynamics of phototrophic purple non sulphur bacteria compared with other asymbiotic nitrogen fixers in rice fields of Egypt. World Journal of Microbiology and Biotechnology, 15(3), 359–362.
FAO (Food and Agriculture Organization of the United Nations). (2014). FAOSTAT statistical database. [Online]. Retrieved from
Ferreira, J.S., Baldani, J.I., & Baldani, V.L.D. (2010). Selecao de bactérias diazotroficas em duas variedades de arroz. Acta Scientiarum Agronomy, 32(1), 179–185.
Gomez, K. A. (1972). Techniques for field experiment with rice. International Rice Research Institute, Los Banos.
Isawa, T., Yasuda M., Awazaki, H., Minamisawa, K., Shinozaki, S., & Nakashita, H. (2010). Azospirillum sp. strain B510 enhances rice growth and yield. Microbes and Environments, 25 (1), 58–61.
Islam, M. Z., Yasmin, S., Malik, K. A., Sattar, M. A., & Hafeez, F. Y. (2005, October). Potentials of PGPR to rice production in Bangladesh. In International Seminar on Rice Crop, Lahore, Pakistan (pp. 87-96).
Keyeo, F., Ai'shah, O.N., & Amir, H.G. (2011). The effects of nitrogen fixation activity and phytohormone production of diazotroph in promoting growth of rice seedlings. Biotechnology10(3), 267-273.
Kim, H.Y., Lieffering M., Miura S., Kobayashi K., & Okada M. (2001). Growth and nitrogen uptake of CO2-enriched rice under field conditions. New Phytologist. 150(2), 223–229.
Kumar, V., & Narula, N. (1999). Solubilization of inorganic phosphates and growth emergence of wheat as affected by Azotobacter chroococcum mutants. Biology and Fertility of Soils, 28(3), 301–305.
Ladha, J.K., & Reddy, P.M. (2003). Nitrogen fixation in rice systems: state of knowledge and futureprospects. Plant and Soil, 252(1), 151–167.
Li, Y., Chen, X., Shamsi, I.H., Fang, P., & Lin, Y. (2012). Effects of irrigation patterns and nitrogen fertilization on rice yield and microbial community structure in paddy soil. Pedospher, 22 (5), 661–672.
Liu, Q.H., Wu, X., Li, T., Ma, J.Q., & Zhou X.B. (2013). Effects of elevated air temperature on physiological characteristics of flag leaves and grain yield in rice. Chilean Journal of Agricultural Research, 73(2), 85-90.
Malik, K. A., Mirza, M. S., Hassan, U., Mehnaz, S., Rasul, G., Haurat, J., & Normand, P. (2002). The role of plant-associated beneficial bacteria in rice-wheat cropping system. Biofertilisers in action. Rural industries research and development Corporation, Canberra, 73-83.
Manzoor, Z., Awan, T.H., Zahid, M.A., & Faiz, F. A. (2006). Respons of rice crop (SUPER BASMATI) to different nitrogen levels. Journal of Animal and Plant Science, 16 (1-2): 52-55. 
Mirza, M. S., Rasul, G., Mehnaz, S., Ladha, J. K., So, R. B., Ali, S., & Malik, K. A. (2000). Beneficial effects of inoculated nitrogen-fixing bacteria on rice. The quest for nitrogen fixation in rice, 191-204.
Mukhopadhyay, M., Datta, J.K., & Garai, T.K. (2013). Steps toward alternative farming system in rice. European Journal of Agronomy, 51, 18–24.
Panahi A., Aminpanah H., & Sharifi P. (2015). Effect of Nitrogen, Bio-Fertilizer, and Silicon Application on Yield and Yield Components of Rice (Oryza sativa L.). Philippine Journal of   Crop Science, 40 (1), 76-81.
Pedraza, R.O., Bellone, C.H., de Bellone, S.C., Sorte, P.M.F.B., & Teixeira, K.R.S. (2009). Azospirillum inoculation and nitrogen fertilization effect on grain yield and on the diversity of endophytic bacteria in the phyllosphere of rice rainfed crop. European Journal of Soil Biology, 45(1), 36–43.
Pregl F. (1945). Quantitative organic micro analysis. 4th ED. J. & Achurnil, London.
Rodrigues, E.P., Rodrigues, L.S., Oliveira, A.L.M., Baldani, V.L.D., Teixeira, K.R.S., Urquiaga, S., &    Reis, V.M. (2008). Azospirillum amazonense inoculation: effects on growth yield and N2 fixation of rice (Oryza sativa L.). Plant and Soil, 302(1-2), 249–261.
SAS (2004). SAS Institute, version 9.1.3. Cary, NC, USA.
Sinclair, T.R., & Horie, T. (1989). Leaf nitrogen, photosynthesis, and crop radiation use efficiency: a review. Crop Science, 29(1), 90–98.
Trouwborst, G., Hogewoning, S.W., Harbinson, J., & van Ieperen, W. (2011). Photosynthetic acclimation in relation to nitrogen allocation in cucumber leaves in response to changes in irradiance. Physiologia Plantarum, 142(2), 157-169.
Vessey, J.K. (2003). Plant growth promoting rhizobacteria as biofertilizers. Plant and Soil, 255(2), 571–586.
Weerakoon, W.M.W., Ingram, K.T., & Moss, D.N. (2005). Atmospheric CO2 concentration effects on    N partitioning and fertilizer N recovery in field grown rice (Oryza sativa L.). Agriculture, Ecosystem and Environment, 108(4), 342–349.
Yanni, Y.G., & El-Fattah, F.K.A. (1999). Towards integrated biofertilization management with free living and associative dinitrogen fixers for enhancing rice performance in the Nile delta.   Symbiosis, 27(3-4), 319–331.