氮肥运筹方式对油菜产量、氮肥利用率及氮素淋失的影响

通过盆栽模拟试验研究了不同氮肥运筹方式对油菜产量、氮肥利用率、氮素淋失及氮素平衡的影响。试验设5个处理：不施氮肥（CK）,氮肥全部基施（TJ）,氮肥60%基施、40%做越冬肥追施（TJD）,氮肥60%基施、40%做薹肥追施（TJT）,氮肥60%基施、20%做越冬肥、20%做薹肥追施（TJDT）。研究结果表明,氮肥分期施用可明显增加油菜产量,提高氮肥利用率,其中以TJDT处理效果最佳,与TJ处理相比,TJDT处理的产量、氮肥农学利用率及表观利用率分别提高了17.6%、2.1kg·kg^-1氮和4.9%。同时,TJDT处理的氮素淋失量也最小。氮素平衡计算结果表明,不同时期追施氮肥对氮素平衡影响不大,但是均比氮肥集中做基肥施用（TJ）的表观损失明显减小。尽管油菜收获后,各施氮处理土壤氮素均有盈余,但分期施肥盈余量明显高于TJ。研究表明在油菜生产中,氮肥分期施用既能提高油菜籽的产量和氮肥的利用效率,又可获得较好的环境效应。

Effect of nitrogen management mode on yield, nitrogen using efficiency and nitrogen leaching of rapeseed

Pot experiment was carried out to determine the effects of different nitrogen （N） management on rapeseed yield,N efficiency,N leaching and N balance.5 treatments were involved： CK （no N fertilizer）,TJ （N fertilizer all applied as basic manure）,TJD （60% of N fertilizer applied as basic with 40% top-dressed before winter）,TJT （60% applied as basic with 40% were top-dressed at bolting stage）,TJDT （60% applied as basic with 20% top-dressed before winter,and 20% top-dressed at bolting stage）.Results showed that both yield and N efficiency of uptake increased significantly with N fertilizer split application （TJD,TJT and TJDT）.Among these treatments,TJDT was the most beneficial and improved 17.6% of yield,2.1kg·kg^-1 N of agronomic efficiency and 4.9% recovery efficiency than those of TJ treatment respectively.It also had the lowest risk of N leaching than others.The N balance investigation showed that TJ led to loss of N fertilizer.There was no significant difference among N split application modes on N balance.Soil N was surplus from all 5 treatments after canola harvesting,but split modes had much lower N left.It indicated that N fertilizer split application was environmental friendly,its N was highly utilized and increased yield.