Effect of Nitrogen Management at the Reproductive Phase in Transplanted Rice

Abstract

Nitrogen (N) is not only a major nutrient but also the most limiting nutrient element for rice cultivation. Efficient N fertilizer management is critical for the economic production of rice and the long-term protection of environmental quality. Considering the above facts, two field experiments were designed at Bangladesh Rice Research Institute (BRRI) farm, Gazipur, Bangladesh during the transplanting Aman season (July to November), 2018-19 and the Boro season (December to May), 2019-20 to study the effects of four different N management on growth, yield attributes, yield and nitrogen uptake by rice variety BRRI dhan75 and BRRI dhan89. The experiment was laid out in a randomized complete block design involving four different N management at different stages (Active tillering, Panicle initiation, Flowering and Heading) replicated three times. Results revealed that 69 kg N ha-1 (29.5 kg as basal + 29.5 kg at 15 DAT + 10 kg ha-1 at heading) would be a better option for higher yield in T. Aman rice While 120 kg N ha-1 (23 kg as basal + 40 kg at 20 DAT + 40 kg at 40 DAT + 17 kg ha-1 at heading) significantly improved growth, yield attributes and grain yield as well as nitrogen uptake by grain and straw. From the results, it can be said that application of N @10 kg ha-1 for T. Aman rice and N @17 kg ha-1 for Boro rice at the heading stage would reduce sterility and give a higher yield than BRRI recommended management. Hence, the study suggests that nitrogen management at the reproductive phase gives better performance to the T. Aman and Boro rice.