【摘要】 2004年至2005年在浙北富阳研究不同施氮水平下分次施氮对单季稻氮素利用率及稻田生态经济适宜施氮量的影响.在单季稻不同生育期内,测定水稻植株叶、茎、穗、根全氮含量和土壤全氮含量并进行统计分析.结果表明,不同施氮水平的水稻产量随着施氮量的增加呈现先增后降的趋势;与低施氮水平相比,高施氮水平对水稻增产和对氮肥吸收利用率差异不显著,反而向环境中输入较多的氮素;2年的试验表明,应调整返青期、分蘖期和孕穗期施氮比例,实现产量和氮素利用效率的同步提高.浙北富阳高肥力稻田中施氮水平需兼顾水稻生产、生态、经济效益的影响,其适宜施氮量为195～232kg·hm-2.更多还原

【Abstract】 The effect of N fertilizer rates on N use efficiency at different growth stages of rice and its eco-economic suitable N application amount in high-yielding paddy field in Fuyang,northern Zhejiang Province were studied from 2004 to 2005. The nitrogen content of rice leaf,stem,spike,root and in soil was determined at different growth stage of rice under N treatments. The results show that rice yield under different N supply levels increased firstly and dropped as the N rates increase. Compared with the low N applied rate,the higher rate of N input produced no significant effect on rice yield and N use efficiency. However,more N was discharged into environment with higher N application. According to the results of N use efficiency at different growth stages of rice in two years,the proportion of nitrogenous fertilizer input should be adjusted at regreening,tillering and booting stage. According to the rice production and eco-economy benefit analysis,the application amount of N between 195-232 kg·hm-2 could be better for maintaining high rice yield and minimizing N loss in paddy field.更多还原