氮肥运筹对桂两优2号干物质生产及氮肥利用率的影响

【目的】以广西超级稻品种桂两优2号为材料,研究不同氮肥运筹方式对其干物质生产及氮肥利用率的影响。【方法】进行田间试验,设置3个施氮水平,分别为0（N0）、210（N1）和255（N3）kg/ha,两种施氮比例分别为基肥∶蘖肥∶穗肥=5∶3∶2（F1）和4：3：3（F2）,共计5个处理（N0、F1N1、F1N2、F2N1和F2N2）,测定不同处理下桂优2号干物质积累及氮肥利用率。【结果】施氮显著增加了桂两优2号不同生育期干物质积累量,且F2N1和F2N1处理在穗后干物质增加量及其对产量贡献率上均显著高于其他处理;桂两优2号各生育期吸氮量随施氮量的增加而提高,施肥方式F2更有利于桂两优2号对氮素的吸收;相同施肥条件下,F2处理的产量和氮肥偏生产力（NPFP）、氮肥农学利用率（NAE）和氮肥吸收利用率（NRE）均较F1处理有所增加,F2N2处理产量最高,但与F2N1处理差异不显著,而F2N1处理的NPFP、NAE和NRE均达到最高水平。【结论】施氮量210kg/ha（N1）、施氮比例为基肥∶蘖肥∶穗肥=4∶3∶3（F2）处理,可在晚稻实现桂两优2号高产高效,其产量达8170.2kg/ha,NPFP、NAE和NRE分别为38.9kg/kg、12.6kg/kg和41.5%。

Effects of nitrogen management on dry matter accumulation and nitrogen use efficiency of Guiliangyou 2

Objective Super rice Guiliangyou 2 was used to study the effects of nitrogen （N） management on dry matter （DM） accumulation and N-use efficiency in Guangxi Province. Method Field trials with five N treatments three nitrogen rates： 0 （N0）, 210 （N1） and 255 （N 2 ） kg/ha; two N fertilizer distribution ratio： 5：3：2 （F1） and 4：3：3 （F2） for basal, tillering and heading dressings, respectively were conducted. ResultThe results showed that DM accumulation of Guiliangyou 2 at different stages significantly increased due to nitrogen fertilizing. Thus, compared to other treatments, F2N1 and F2N1 treatments raised DM increment after heading and its contribution to yield. The total nitrogen uptake of Guiliangyou 2 increased with the increasing applied N, and F2 treatment was beneficial to improve the absorption of nitrogen from the soil and N fertilizer. With the same N fertilizer rate, a certain increase of NPFP, NAE and NRE in F2 treatments were found compared with F1. Despite F2N2 treatment obtaining the highest yield, there was no significant difference between F2N1 and F2N2 , NPFP, NAE and NRE of F2N1 were the highest. Conclusion F2N1 treatment, with N rate of 210 kg/ha and N fertilizer distribution ratio of 4：3：3 for basal, tillering and heading dressings, could obtain high yield with high N-use efficiency in the production of Guiliangyou 2 sown in late season. The yield of F2N1 treatment was 8170.2 kg/ha. NPFP, NAE and NRE were 38.9 kg/kg, 12.6 kg/kg and 41.5%, respectively.