Abstract: An indica hybrid rice combination Shanyou 63 and a japonica variety Wuyujing 3 were grown in tanks.Three nitrogen(N) levels,0N(0g/m²),NN(normal level of N,4.5g/m²) and HN(high level of N,9.0g/m²),were applied at the beginning of heading,and three soil moisture treatments,WW(well-watered),MD(moderate soil drying,soil water potential at-25kPa) and SD(severe soil drying,soil water potential at-50kPa),were conducted from 7d after heading to maturity.The coupling effects of soil moisture and nitrogen nutrient on rice quality were investigated.The results showed that grain yield,brown rice rate,milled rice rate and head rice rate were the greatest,while chalky grain rate and chalkiness were the lowest,under the MD treatment,irrespective of the N level.The SD treatment significantly reduced grain yield and degraded the milling quality,appearance quality,and eating quality at the 0N level.The differences in grain yield,milling quality,appearance quality and eating quality between SD and WW were not significant at MN and HN levels.This suggests that the interaction between soil moisture and N level affects grain yield and quality of rice,and that soil water potential at-25kPa during grain filling and the N rate at 45kg/hm² applied at the beginning of heading benefit the formation of high-yielding and good quality.

Key words: rice, nitrogen, soil moisture, coupling effect, grain yield, grain quality

摘要： 杂交籼稻汕优63和粳稻武育粳3号种植于土培池，于始穗期进行0N（0 g/m2）、NN（中氮，4.5 g/m2 ）和HN（高氮，9.0 g/m2）3种施氮量处理，于抽穗后7 d至成熟期设置了WW（保持浅水层）、MD（轻度落干，土壤水势保持-25 kPa）和SD（重度落干，土壤水势保持-50 kPa）3种土壤水分处理，研究了结实期土壤水分和氮素营养对水稻产量与品质的交互影响。在各施氮水平下，产量、糙米率、精米率和整精米率均以MD处理最高，垩白粒率和垩白度均以MD处理最低。在0N下，SD处理降低了产量、碾磨品质、外观品质和食味品质；在MN或HN下，SD处理的产量、碾磨品质、外观品质和食味品质与WW的差异不显著或显著优于WW。说明土壤水分和氮素营养对水稻产量和品质的影响存在着明显的互作效应，结实期土壤水势为-25 kPa、粒肥的施氮量为45 kg/hm2，稻米的品质较优、产量最高。

关键词: 水稻, 氮素, 土壤水分, 交互作用, 产量, 品质