Adoption of appropriate agronomic practices, such as optimum seeding and nitrogen (N) rates, in synchronization with proper water management practice could help improve yield, water productivity and N use efficiency (NUE) of rice (Oryza sativa L.). Field experiments were conducted at the research farm of the Asian Institute of Technology during the dry seasons (November–March) of 2017–2018 and 2018–2019 to evaluate the effects of seeding (S) (95 [S₉₅], 125 [S₁₂₅] and 155 [S₁₅₅] kg ha⁻¹) and N (0 [N₀], 60 [N₆₀] and 120 [N₁₂₀] kg ha⁻¹) rates under different water regimes (continuous flooding [CF] and safe alternate wetting and drying [AWD15]) on yield, water productivity and NUE of wet direct-seeded rice. Application of 120 kg N ha⁻¹ (N₁₂₀) resulted in the highest grain yield and water productivity (by 76% and 78%, respectively, compared with N₀), which were statistically similar with N₆₀. Less plant population in lower seeding rates (S₉₅ and S₁₂₅) provided better results in terms of vegetative and reproductive growth, grain yield and water productivity. Rice grown under AWD15 resulted in statistically similar grain yield with rice maintained under CF, but there was 40–44% more water savings depending on seeding rates and 68% higher water productivity in AWD15-treated plots. Improving sink capacity and dry matter accumulation is key to ensuring better grain yields even with reduced N and seeding rates under AWD15. A stronger relationship between grain yield and spikelet number panicle⁻¹ as well as between shoot dry matter and spikelet number panicle⁻¹ was observed under CF (r = 0.61 and r = 0.57, respectively) compared with AWD15 (r = 0.45 and r = 0.41, respectively). N₆₀ had significantly higher partial factor productivity (64.6) of applied N than N₁₂₀ (36.4). S₉₅ and S₁₂₅ resulted in a significant improvement in NUE compared with S₁₅₅. This result suggests that desirable grain yield and water productivity as well as better NUE could be achieved by decreasing N rate from 120 to 60 kg ha⁻¹, and thus significant reduction in fertilizer input cost could be possible along with environmental benefits. In addition, decreasing seeding rate coupled with AWD15 is recommended to reduce the input cost and total water input to make the wet direct-seeded rice cultivation system more sustainable and profitable.

采用适当的农艺措施，如最佳播种和氮 (N) 率，与适当的水管理措施同步，可以帮助提高水稻 ( Oryza sativa L.) 的产量、水分生产率和氮利用效率 (NUE )。2017-2018 年和 2018-2019 年旱季（11 月-3 月）在亚洲理工学院研究农场进行了田间试验，以评估播种（S）（95 [S ₉₅ ]、125 [S ₁₂₅ ] 和 155 [S ₁₅₅ ] kg ha ^-1 ) 和 N (0 [N ₀ ], 60 [N ₆₀ ] 和 120 [N ₁₂₀ ] kg ha ^-1) 在不同水分条件下（连续洪水 [CF] 和安全交替干湿交替 [AWD15]）对湿直播水稻的产量、水分生产率和 NUE 的影响。施用 120 kg N ha ^-1 (N ₁₂₀ ) 导致最高的谷物产量和水分生产力（分别比 N _{0 高}76% 和 78% ），这与 N ₆₀在统计上相似。以较低的播种率（S ₉₅和 S ₁₂₅) 在营养和生殖生长、谷物产量和水生产力方面提供了更好的结果。在 AWD15 下种植的水稻与在 CF 下种植的水稻在统计学上产生了相似的谷物产量，但在 AWD15 处理的地块中，根据播种率的不同，节水量增加了 40-44%，水生产力提高了 68%。即使在 AWD15 下减少氮和播种量，提高汇容量和干物质积累是确保更好的粮食产量的关键。与 AWD15（r = 0.45 和 r = ）相比，在 CF（分别为 r = 0.61 和 r = 0.57）下观察到谷物产量和小穗数穗^-1之间以及地上部干物质和小穗数穗^-1之间更强的关系（分别为 r = 0.61 和 r = 0.57） 0.41，分别）。ñ ₆₀施氮的部分要素生产率 (64.6) 显着高于 N ₁₂₀ (36.4)。与 S ₁₅₅相比，S ₉₅和 S ₁₂₅导致 NUE 的显着改善。该结果表明，通过将氮含量从 120 kg ha ^-1降低到 60 kg ha ^-1可以实现理想的谷物产量和水分生产率以及更好的 NUE ，因此可以显着降低肥料投入成本并带来环境效益。此外，建议降低播种量并结合 AWD15 以降低投入成本和总水量投入，从而使湿直播水稻栽培系统更具可持续性和盈利性。