%0 Journal Article %T Study of nitrogen use efficiency and yield of rice influenced by deep placement of nitrogen fertilizers %A K Mix %A MM Rahman %A MR Islam %A RS Rea %J SAARC Journal of Agriculture %D 2019 %R https://doi.org/10.3329/sja.v17i1.42764 %X Continuous increase of nitrogen fertilizer use adversely affecting the soil health as well as the environment. It necessitates the systematic study of the impact of nitrogen (N) fertilizer use-reduction on crop yield. In this article, the effects of deep placement of nitrogen fertilizers on nitrogen use efficiency (NUE) and yield of rice variety ¡°BRRI dhan46¡± were investigated and compared for three N formulations: urea super granule (USG), NPK briquettes and prilled urea (PU). The experiment was conducted in randomized complete block design (RCBD) with eight N treatments replicated three times. The treatments were applied by varying doses (0, 52, 78 and 104 kg ha-1) of nitrogen fertilizers in a known identical soil and weather condition. Applications of PU, USG and NPK briquettes exhibited significant differences on yield attributes of rice. Results revealed maximum grain yield of 6.391 t ha-1 (54% increases over control) for the dose USG 104 kg ha-1 which is statistically similar to the dose USG 78 kg ha-1 and NPK briquettes 104 kg ha-1. The deep placement of USG and NPK briquettes enhanced both the recovery of applied N and N use efficiency compared to broadcast application of prilled urea. However, USG 78 kg ha-1 showed maximum apparent N recovery, N use efficiency, gross margin and marginal benefit-cost ratio. Thus, an application of 78 kg ha-1 USG can be recommended for profitable cultivation of rice variety BRRI dhan46 %U https://www.banglajol.info/index.php/SJA/article/view/42764