不同施氮水平对杂交水稻群体特征和产量的影响

Effect of N Application with Different Level on Characteristic and Yield of Hybrid Rice Population

[目的]探索超高产条件下水稻氮素需肥规律和各群体质量指标。[方法]以杂交水稻Q优1号为试材，251．7kg／hm^2为标准施氮量（ST），设5个施氮处理，在田间精确定量栽培条件下比较不同施氮量对水稻产量和群体质量的影响。[结果]在ST±15％的施氮范围内，单位面积穗数变化不大，低于或高于此范围，单位面积穗数均降低。施肥处理中每穗颖花数相差不大，结实率和千粒重都以ST处理为最高。高峰苗数及有效穗薮以ST-15％的氮肥用量处理为最高。成穗率以ST和ST＋15％的氮肥用量处理较高。最大叫、茎鞘叶物质输出量和茎鞘叶物质输出率以ST施氮量为最高，对稻谷产量贡献率以ST-15％施氮量为最高。ST与ST＋15％的施肥处理上5叶表现出高产的叶长次序。齐穗-成熟期的干物质积累量以ST施氮量为最高。[结论]Q优1号获得高产的适宜用氮量为256．4kg/hm^2。

[ Objective ] The purpose was to explore N fertilizer need law and various population quality indices under super-high yield. [ Method] With hybrid rico variety Qyou 1 as tested material and 251.7 kg/hm^2 as standard N application rate （ST）, 5 treatments of N application were set up to compared the different N application rate on the yield and population quality in rice under precise quantity planting. [ Result] The ears per unit area varied slightly in N application range of ST ± 15% and all decreased below or over this N application range. Among 5 treatments of N application, the spikelet number per ear differed lilltle, the seed setting rate and 1 000-grain weight were highest in ST treatment, the seedlings in peak stage and effective ears were highest in ST- 15% N application treatment, the earbearing tiller rate was highest in ST and ST＋15% N application treatment, the maximum LAI and storage material output amount and output rate in the stem-leaf sheath were highest in ST N application treatment and the contribution to rico yield was highest in ST - 15 % N application treatment. The leaf length order of 5 leaves in wheat showed high yield trend in ST and ST ＋ 15 % N application treatment. The dry matter accumulation from full heading to mature stage was highest in ST N application treatment. [Conclusion]The optimum N application rate for getting high yield in Qyou 1 was 256.4 kg/hm^2.