Abstract: With the same planting density（3×105hills/hm2 for early rice and 2.5×105 hills/hm2 for late rice）, the effect of rowspacing on the yield of superhighyielding rice was studied at three nitrogen application levels with early rice Ganxin 203 and Luliangyou 996 and late rice Tianyouhuazhan and Ganxin 688 as materials. Narrow rowspacing was favorable for higher yield of the four tested materials with no nitrogen application. With the same nitrogen application levels, medium rowspacing produced higher yield for Ganxin 203, wide or narrow rowspacing for Luliangyou 996 and Tianyouhuazhan, and narrow rowspacing for Ganxin 688. Number of effective panicles was the main factor responsible for the effect of rowspacing on yield for both Luliangyou 996 and Tianyouhuazhan, but number of grains per panicle for Ganxin 203, and seedsetting rate for Ganxin 688. Different responses to rowspacing among different materials could be attributed to the number of grains per panicle and panicle forming rate, which were lower for Ganxin 203 and higher for Luliangyou 996 and Tianyouhuazhan, and to higher leaf area index for Ganxin 688. The appropriate rowspacing was 33.0 cm×10.0 cm or 20.6 cm×16.0 cm for early rice Luliangyou 996, 25.4 cm×13.0 cm for early rice Ganxin 203, 40.0 cm×10.0 cm or 20.0 cm×20.0 cm for late rice Tianyouhuazhan, and 20.0 cm×20.0 cm for late rice Ganxin 688.

Key words: superhigh-yielding rice, early rice, late rice, rowspacing, plant density, yield, nitrogen use efficiency

摘要： 在30万蔸/hm2（早稻）和25万蔸/hm2（晚稻）密度下，以超高产早稻陆两优996、淦鑫203和超高产晚稻淦鑫688、天优华占为试验材料，研究了3个施氮水平下不同行株距配置对超高产早、晚稻产量的影响。不施氮时，供试的4个品种（组合）均在窄行距时产量最高；施氮条件下，淦鑫203在中行距时产量最高，陆两优996和天优华占在宽行距和窄行距时产量较高，而淦鑫688在窄行距时产量较高。不同行株距配置对陆两优996和天优华占产量的影响主要是通过影响有效穗数，对淦鑫203主要通过影响每穗粒数，而对淦鑫668则主要通过影响结实率来实现。品种间对行株距配置响应的差异与淦鑫203的每穗粒数较少、成穗率较低，而陆两优996和天优华占的每穗粒数较多、成穗率较高，淦鑫688的叶面积指数较高有关。早稻陆两优996的适宜行株距为33.0 cm×10.0 cm或20.6 cm×16.0 cm，淦鑫203为25.4 cm×13.0 cm；晚稻天优华占为40.0 cm×10.0 cm或20.0 cm×20.0 cm，淦鑫688为20.0 cm×20.0 cm。

关键词: 超高产水稻, 早稻, 晚稻, 行株距配置, 栽插密度, 产量, 氮肥利用率