对目前主推的高产杂交水稻氮利用率进行大田评比试验。结果表明，在中低氮条件下杂交水稻协优52、Y两优2号表现出较高的产量与氮利用率；协优52、Y两优2号产量均较对照增加5%以上，氮利用率协优52增加10%以上、Y两优2号增加5%以上。高产杂交水稻产量与单位面积有效穗数受氮肥影响较大。在中低氮条件下，单位面积有效穗数少、氮积累总量低而单株稻谷质量高的杂交组合具有较高的氮利用率。

NUE（nitrogen use efficiency） of the main released high yield hybrid rice combinations were tested on the field. The results indicat that Xieyou 52 and Y liangyou 2 showed higher yield and NUE than other hybrid rice combinations, under low and medium nitrogen condition. Compared with the control, the yield of Xieyou 52 and Y liangyou 2 increased by more than 5%; NUE of Xieyou 52 increased by more than 10% and Y liangyou 2 increased by more than 5%. The yield and effective panicles of high yield hybrid rice are greatly influenced by nitrogen.Under low nitrogen condition, the hybrid combinations of fewer effective panicles, lower nitrogen accumulation and higher grain weight per plant shows higher nitrogen use efficiency .