Evaluation and Comparison of the Effects of Different Application Methods and Sources of Nitrogen on Nitrogen Use Efficiency of Hashemi Rice Variety

In order to achieve an effective approach to improve nitrogen use efficiency in rice, a field experiment was conducted based on randomized complete block design with three replications and 13 treatments on a local rice variety, namely, Hashemi, in Rice Research Institute of Iran (Amol) during 2015 and 2016. The treatments included: N0: no N, N1: split application of 55.2 kg ha-1 N from source of urea (recommended for Hashemi variety), (N2, N3), (N4, N5) and (N6, N7) application of 55.2 and 27.6 kg ha-1 N from SCU, USG and AS sources, respectively; N8: application of nitrogen  nanofertilizer; N9, N10 and N11: application of Azospirillium, Azotobacter, and Azospirillium + Azotobacter. In addition to the mentioned sources, in N8 to N11 treatments, 27.6 kg ha-1 N from urea was used. N12: Farmers’ fertilizer practice (Pre planting application of 55.2 kg ha-1 N from urea). Results of the experiment showed that the effect of treatments on the measured traits, except nitrogen content of straw, caused a significant (p<0.05) difference. The highest grain yield was obtained from N6 (4542 kg ha-1). The performance of N5 (deep placement of 27.6 kg ha-1 Nfrom source of USG) was not significantly different from the treatment with the highest grain yield (N6). The highest amount of PFP, AEN and REN was obtained from N5 treatment and the highest PEN and IEN[H1]  was obtained from N10. N5 increased grain yield by 4.6% and recovery efficiency by 59.4% in compared to N12. The highest amount of N uptake (119.5 kg ha-1) was obtained from N4 treatment. Based on the results, it could be concluded that the deep placement of USG fertilizer has relative advantage compared to other N supplying sources because of enhanced amount of N uptake and reduced N losses.



 [H1]Please define these symbols.