关键词: 桃优香占, 氮肥用量, 农艺性状, SPAD值, 产量

Abstract: To investigate the effects of different nitrogen application rates on yield and agronomic characteristics of cultivar-Taoyouxiangzhan under the rice-crayfish co-culture, 5 nitrogen application rates 0 kg/hm²（N0）, 135 kg/hm²（N1）, 150 kg/hm²（N2）, 165 kg/hm²（N3）, 180 kg/hm²（N4） were conducted in this study. The results showed that the maximum tiller number increased by 30%, the SPAD value of leaves increased by 9.38%, and the above-ground dry matter of the spikes at heading stage and milking stage increased respectively by 37.9% and 41.1%. The effective spikes, seed setting rate and thousand-grain weight were respectively increased by 39.1%, 16.3% and 3.69%. The actual yields under the conditions of N1, N2, N3 and N4 were respectively increased by 57.8%, 54.1%, 69.2% and 61.6% compared to the control. The effect of increasing yield is best under the condition of N3, but excessive nitrogen fertilizer application reduces nitrogen fertilizer utilization rate and causes agricultural non-point source pollution. Therefore, rational application of nitrogen fertilizer is of great significance for improving rice yield and protecting the environment.

Key words: Taoyouxiangzhan, nitrogen application rate, agronomic traits, SPAD, yield