Abstract:

【Objective】This study evaluates the yield and nitrogen use efficiency of japonica rice with various panicle types in response to nitrogen application practice and row spacing. We aim to lay a theoretical basis for high-yield and high-efficiency cultivation of rice in Liaoning Province.【Method】A field experiment was conducted in 2019 and 2020 in Shenyang City, using Shendao 9 (a middle-tillering, mid-sized panicle cultivar), Shendao 505 (a relatively high-tillering, small-sized panicle cultivar), and Shendao 527 (a low-tillering, large-sized panicle cultivar) as entries. The study examined the effects of different nitrogen (N) application patterns, including N0 (zero nitrogen), N1 (farmer's practice ), N2 (reduced basal nitrogen), and N3 (reduced and delayed basal nitrogen application), as well as row spacing, including R1 (30 cm row spacing), R2 (25 cm row spacing), and R3 (wide-narrow row spacing, 40+20 cm), on the yield and nitrogen use efficiency of different panicle types of rice.【Result】The results showed that the nitrogen application pattern, row spacing, and their interaction significantly affected grain yield and nitrogen use efficiency of different panicle types of rice. Under N3, Shendao 9 and Shendao 505 showed increased spikelet number per unit area, seed-setting rate, 1000-grain weight, dry matter accumulation, nitrogen accumulation, partial factor productivity (PFP_N), agronomic efficiency (AE_N), and apparent recovery efficiency (RE_N), leading to improvements in yield and nitrogen use efficiency. Shendao 527 achieved high yield under N1 and realized high efficiency under N2. In terms of row spacing, yield, spikelet number per unit area, dry matter accumulation, nitrogen accumulation, PFP_N, AE_N, and RE_N were all highest in R2. Shendao 9 and Shendao 505 obtained the highest yield under N3R2, with yield increases of 18.53% and 14.27%, dry matter accumulation increases of 18.38% and 22.47%, nitrogen accumulation increases of 37.22% and 29.15%, PFP_N increases of 39.30% and 34.25%, AE_N increases of 52.59% and 26.73%, RE_N increases of 27.65% and 17.70%, and a reduction in the contribution rate of soil nitrogen (CRSN) by 15.75% and 8.16% compared to their respective N1R1. Shendao 527 had a higher yield with no significant differences among N1R1, N1R2, and N2R2, but N2R2 performed better in dry matter accumulation, nitrogen accumulation, and nitrogen utilization.【Conclusion】Therefore, the optimal combination of nitrogen application pattern and row spacing for Shendao 9 and Shendao 505 is reduced and delayed basal nitrogen application with 25 cm row spacing. For Shendao 527, the optimal condition is reduced basal nitrogen applicaton with 25 cm row spacing, allowing all three cultivars to achieve high yield and improved nitrogen utilization.

Key words: japonica rice, panicle type, nitrogen application pattern, row spacing, yield, nitrogen use efficiency

摘要：

【目的】研究施氮方式与行距配置对不同穗型粳稻产量和氮素利用率的影响，明确其最佳组合，为辽宁水稻高产高效栽培提供理论依据。【方法】以沈稻9号(穗粒兼顾型)、沈稻505(穗数型)和沈稻527(穗重型)为材料于2019年和2020年在沈阳市进行田间试验，设置N0(不施氮肥)、N1(农户方式)、N2(底氮减施)、N3(底氮减施后移)4种施氮方式和R1(常规行距30 cm)、R2(缩行增密25 cm)、R3(宽窄行40 cm+20 cm) 3种行距配置，分析其对不同穗型粳稻产量及氮素利用率的影响。【结果】施氮方式与行距配置对不同穗型粳稻产量和氮素利用率有极显著影响和互作效应。N3可以通过提高单位面积颖花数、结实率、千粒重、干物质积累量、氮素积累量、氮肥偏生产力、氮肥农学利用率和氮肥回收利用率来增加沈稻9号、沈稻505的产量和氮素利用率，但沈稻527却在N1实现高产，在N2实现高效目标。对于行距配置的响应，3个品种表现大致相同，产量、单位面积颖花数、干物质积累量、氮素积累量、氮肥偏生产力、氮肥农学利用率和氮肥回收利用率均在R2达到最高。施氮方式与行距配置互作显示，沈稻9号和沈稻505在N3R2产量最高，与N1R1相比，分别增加了18.53%和14.27%的产量，18.38%和22.47%的干物质积累量，37.22%和29.15%的氮素积累量，39.30%和34.25%的氮肥偏生产力，52.59 %和26.73%的氮肥农学利用率，27.65%和17.70%的氮肥回收利用率，降低了15.75%和8.16%的土壤氮依存率。沈稻527产量则在N1R1、N1R2和N2R2处理下较高且差异不显著，但比较3个组合的干物质积累量、氮素积累量以及氮素利用率，N2R2表现优异。【结论】在本试验条件下，沈稻9号、沈稻505的最适组合为底氮减施后移和行距25 cm，沈稻527为底氮减施和行距25 cm，此时3个品种高产且氮肥利用率也较高。

关键词: 粳稻, 穗型, 施氮方式, 行距配置, 产量, 氮素利用率