关键词: 甬优538, 秀水134, 施氮比例, 产量效应

Abstract: By the mixed regression design, the appropriate ratio of applying nitrogen fertilizer for japonica hybrid rice Yongyou 538 and japonica variety Xiushui 134 in different stages in rice field were studied, and the relationship between factors and grain yields were defined initially. The result indicated that effects of nitrogen fertilizer were as follows: culm fertilizer（CF）＞seedling fertilizer（SF）＞base fertilizer （BF）＞booting fertilizer（BOF） in Yongyou 538; SF＞BF＞CF＞BOF in Xiushui 134. There were significant synergy enhancing effects among BF×BOF, BF×SF×CF, BF×SF×BOF, SF×CF×BOF in Yongyou 538; and BF×BOF, SF×CF, SF×BOF, BF×CF×BOF in Xiushui 134. Under the constraint condition of factor （∑Xi=1）, it showed a parabolic curve relationship between single ratio level and yield, in which the largest curve fluctuation of applying nitrogen fertilizer in booting stage was appeared both in Yongyou 538 and Xiushui 134. Therefore, over-applying nitrogen in booting stage should be avoided. The optimum ratio of applying nitrogen fertilizer is suggested as 31.0∶28.8∶21.4∶18.7 for Yongyou 538 and 24.9∶37.3∶11.5∶26.3 for Xiushui 134.

Key words: Yongyou 538, Xiushui 134, ratio of applying nitrogen, yield effect