This experiment aimed to study the efficacy of different nitrogen (N) management approaches in winter rice. The experiment consisted of two rice varieties: 1) BRRI (Bangladesh Rice Research Institute) dhan29-an inbred and 2) Dhanigold-a hybrid, and eight N management approaches: 1) BRRI recommended N (control), 2) Soil analysis based N management, 3) N application based on Agro-ecological zone, 4) 20 kg•N•ha −1 at ≤35 SPAD (Silicon photon activate diode) value, 5) 30 kg•N•ha −1 at ≤35 SPAD value, 6) 20 kg•N•ha −1 at ≤3.0 LCC (leaf colour chart) value, 7) 30 kg•N•ha −1 at ≤3.0 LCC value and 8) Urea Super Granule. Between two varieties, hybrid Dhani gold produced higher grain yield (6.67 t•ha −1 ) than the inbred BRRI dhan29. Application of 20 kg•N•ha −1 at ≤3.0 LCC value gave the highest grain yield (7.10 t•ha −1 ), whereas the lowest grain yield (5.92 t•ha −1 ) was found from the SPAD approach with 20 kg•N•ha −1 at ≤35 SPAD value. In case of treatment interaction highest grain yield (7.34 t•ha −1 ) was found in BRRI dhan29 coupled with 20 kg•N•ha −1 at ≤3.0 LCC value with 18 kg•N•savings•ha −1 over control, maximum gross income (146,800 BDT•ha −1 ) and net benefit (142,120 BDT•ha −1 ), which was statistically identical with the grain yield from the interaction of Dhani gold and 30 kg•N•ha −1 at ≤3.0 LCC value but required 42 kg•extra•N•ha −1 (over control). The lowest grain yield (5.19 t•ha −1 ) was found when Dhanigold was coupled with 30 kg•N•ha −1 at ≤35 SPAD value, while the 20 kg•N•application•ha −1 at ≤35 SPAD value gave moderate yield (6.87 t•ha −1 ) with considerable higher gross (139,600 BDT•ha −1 ) and net (136,090 BDT•ha −1 ) incomes than the control (gross: 121,000 and net: 115,600 BDT•ha −1 ). The results reveal that 20 kg•N•ha −1 at ≤3.0 LCC value appeared as the promising practice for inbred BRRI dhan29, and 30 kg•N•ha −1 at ≤35 How to cite this paper: Jahan, N.A., SPAD value for hybrid Dhanigold in terms of yield, N use efficiency and economic benefit of winter rice.
