The effect of combined application of biochar, Azospirillum lipoferum and nitrogen on yield and yield components of rice (Oryza sativa L.) in two flooding and intermittent irrigation methods

The present study investigates the effect of combined application of biochar, Azospirillium lipofrom bacteria and nitrogen in two flooding and intermittent irrigation methods on yield and yield components of rice (Oryza sativa L. cv. ‘Tarom Hashemi’). The experiment is done in split-split plot arrangement based on a complete randomized block design with three replications at the research farm of Sari Agricultural Sciences and Natural Resources University between two consecutive years of 2017 and 2018. The treatments are two irrigation methods (flooding and alternation irrigation regimes) as main plot and nine fertilizers levels (100%, 75%, and 50% nitrogen in combination with control (without biochar), 20 and 10 tons of biochar per hectare) and seedling inoculation with Azospirillum lipoferum (inoculation and non-inoculated control) as sub and sub-sub plots, respectively. According to the significance of the studied factors’ effects on the measured traits, application of 20 tons of biochar along with 75% to 100% of the recommended nitrogen show the greatest impact on rice yield and yield components in both intermittent and flooding irrigation methods. Since, the effectiveness of biochar in imtermittent irrigation is more significant, it can be concluded that the application of 20 tons of biochar per hectare plus 75% to 100% of the recommended nitrogen could greatly compensate the yield reduction due to reduced water consumption in intermittent irrigation, compared to the flooding irrigation.