[Objectives] Artificial surface application in paddy fields after the transplanting is one of the main reasons resulting in low nitrogen use efficiency.This paper mainly discussed effect of mechanized topdressing polymer-coated mixed fertilizer on rice yield and nitrogen use efficiency.[Methods] The experiments were conducted at Daxing Farm in Heilongjiang Province from 2013 to 2015.Under the same total fertilizer and base fertilizer dosages,the control topdressing was urea broadcasting at tillering stage and heading stage of rice;the treatment topdressing was mechanized topdressing of two kinds of polymer-coated urea,the theoretical release duration was 50 days (OPT1) and 60 days (OPT2),which were mixed with compound fertilizers and applied at 5 cm deep beside the seedling roots.Laboratory and field experiments were conducted to measure the release rate of the polymer-coated urea,nitrogen accumulation and rice yield were analyzed.[Results] The release durations of the two kinds of polymer-coated urea (release rate were 80％) were approximately 40 days and 70 days in 25 ℃ water,respectively,and those in the field were 50 days and 80 days,respectively.Compared with the rice treated with conventional fertilizer practice,the rice treated with mechanical side dressing had shorter time for the reviving of seedlings,and the tiller number at the earlier stage and the highest tiller number were higher,and the rice harvest panicles were significantly increased by 15.8％-21.1％ (P ＜ 0.05),in spite of that rice tiller spike rate was increased slightly.The OPT1 and OPT2 increased rice yields by 13.35％ and 18.69％ (P ＜ 0.05).The mechanized topdressing method increased nitrogen accumulation and dry matter accumulation of rice plants significantly during the whole growth stage.The comprehensive average income was about 3000 yuan/hm2 due to the significant increase of rice yield in OPT1 and OPT2,although a little bit of increase in fertilizer cost.[Conclusions] The mechanized topdressing polymer-coated mixed fertilizer could achieve the goal of deep fertilization in paddy field,increase the rice yield and nitrogen use efficiency.%[目的]追肥表施是稻田氮效率低的主要原因,本研究探讨了深施控释掺混肥对水稻产量和氮效率的影响.[方法]以机插水稻为供试作物,于2013～2015年在黑龙江农垦大兴农场进行田间试验,在肥料总量和底肥用量相同的条件下,设置了常规追肥(在分蘖期和抽穗期追施尿素两次,追施方法为地表撒施,FFP)和机械插秧的同时,在水稻根系侧深5 cm施控释尿素和复合肥处理,供试控释尿素为理论控释期50天(OPT1)和60天(OPT2)两种.在实验室和田间测定了控释尿素的释放情况,调查了水稻氮素积累、产量等指标.[结果]在25℃条件下,两种控释尿素水中释放期(释放率为80％)分别约为40天和70天;在田间对应值分别为50天和80天.与常规施肥相比,OPT1和OPT2促进了水稻快速返青,增加了早期分蘖和最高分蘖数,在水稻分蘖成穗率稍有提高的条件下,OPT1和OPT2处理较FFP处理水稻收获穗数提高了15.8％～21.1％(P＜0.05),水稻产量提高了13.4％～18.7％(P＜0.05).OPT1和OPT2虽然肥料投入稍有增加,由于增产使每公顷增收3000元以上,施用释放期长的控释肥增收效果更好.[结论]机插侧深施用控释掺混肥能保证水稻整个生育期对氮素的需求,成熟期氮积累和干物质积累显著增加.机插侧深施用控释掺混肥实现肥料的深施,增加了水稻产量和氮效率.
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