Enhancing Nitrogen Use Efficiency and Grain Yield in Dry Season Rice Through Optimized Fertilizer Management

Nitrogen (N) is one of the most critical nutrients limiting rice productivity, yet despite numerous management strategies, its use efficiency in Oryza sativa L. remains low, particularly in the dry season where effective application methods are still inadequate. A field study was carried out to explore how different nitrogen (N) application techniques influence the yield and nitrogen use efficiency (NUE) of dry season rice (BRRI dhan29). The experiment followed a randomized complete block design (RCBD) with three approaches to N fertilization-broadcasting, deep placement, and fortification-each tested across three replications. We observed that the deep placement method consistently produced the highest concentrations of both NH4+-N and NO3--N at soil depths of 0-15 cm and 15-25 cm, whereas broadcasting resulted in the lowest levels. Grain yield increased up to 9.68% in fortification and 17.74% in deep placement method as compared to broadcasting method. Deep placement method also reported the highest nutrient uptake (kg ha-1) (N-115.6, P-32.4, K-94.2 and S-21.5), whereas broadcasting had the lowest values. Similarly, NUE was also found maximum in deep placement method and increased 7.72% in fortification and 12.88% in deep placement as compared to broadcasting method. From these results, applying nitrogen through deep placement appears to be the most effective approach for boosting both yield and nitrogen use efficiency in dry-season rice (BRRI dhan29).