氮肥深追可提高玉米对^(15)N的吸收、分配及利用

Improvement of nitrogen fertilizer dressing in deep soil on absorption,allocation and utilization of ^(15)N of maize

【目的】利用15N示踪技术,探索不同追氮方式下玉米植株各组织器官氮素吸收、分配及氮素利用率的情况,为指导寒地玉米高产、高效施肥技术提供理论依据。【方法】试验以玉米品种德美亚3号为试验材料,设置不施氮肥(N0)、浅追施一次(S1)、深追施一次(D1)和深追施二次(D2)4个处理。分析了玉米氮素吸收、分配和利用特性,以及肥料贡献和残留。【结果】氮肥深追施处理玉米不同器官干物质积累量高于浅追,深追二次又显著高于一次(P<0.05);除茎外,深追二次玉米各器官氮素含量均显著高于其它处理(P<0.05);氮肥深追玉米各器官氮素积累量高于浅追,除茎和轴差异不显著外,根、叶和籽粒氮素积累量差异显著(P<0.05);深追处理15N标记氮素含量显著高于浅追(P<0.05),除穗轴外,其它器官间差异达到显著水平(P<0.05);氮素深追15N在玉米根和籽粒分配率高于浅追,在叶和轴内的分配率相反;深追一次15N在茎中的分配率高于浅追,深追二次则低于浅追。氮肥深追与浅追相比,氮素利用率分别显著提高了26.0%和14.1%(P<0.05);氮肥深追二次与一次相比差异也显著(P<0.05);土壤15N残留率深追二次和一次处理分别比浅追一次降低2.1%(P<0.05)和1.2%,氮素损失率分别减少了23.9%和12.9%(P<0.05),肥料氮素贡献率深追二次和一次分别提高了3.6%(P<0.05)和0.6%。【结论】氮肥深追可有效提高玉米的干物质积累、氮素吸收、分配及氮素利用率,降低土壤氮素残留率,提高氮肥的贡献率,且氮肥深追二次好于一次深追。

【Objectives】Using the ^15 N tracing technology, we analyzed effects of different nitrogen topdressing methods on absorption, distribution and utilization of nitrogen of maize in cold zone, and offered theoretical assistance to the reasonable fertilization of the maize.【Methods】Maize cultivar Demeiya 3 was used as material in a field pot experiment, the field experiment was set with the different nitrogen topdressing methods,namely, N0（without N）, once surface topdressing（S1）, once deep topdressing（D1） and twice deep topdressing（D2）. The dry mater biomass and N use efficiencies were analyzed.【Results】Deep dressing of nitrogen were more effective in the biomass accumulation than surface dressing（S1）, and the effect of the D2 was better than that of the D1 treatment（P〈0.05）. The N contents in all the tested organs, except in stem, in the treatment D2 were significantly higher than D1 and S1（P〈0.05）,and the N accumulation in D2 were significantly higherthan in D1 and S1 in all the organs but for stem and shaft（P〈0.05）;The labeling ^15N abundance in D2 and D1 are higher than in S1（P〈0.05） as well, but for axis1（P〈0.05）;The distribution of ^15N in roots and seeds were significantly higher in D2 than in D1 and S1,but those in the leaves and axis were higher in S1 than in D1 and D2;Compared with S1, The use efficiency of 15 N in D2, and D1 were improved by 26.0% and 14.9%respectively（P〈0.05）,the residue of ^15 N decreased by 2.1%（P〈0.05） and 1.2% respectively, and the loss of nitrogen in D2 and D1 were reduced by 23.9% and 12.9% respectively,the contribution of N fertilizer on the increase of n use efficiency were improved 3.6% and 0.6% in D2 and D1 respectively（P〈0.05）.【Conclusions】Twice deep dressing of nitrogen fertilizer performs satisfactory in increasing the absorption and distribution of N in different organs of maize, and increase the usage efficiency of nitrogen and the contribution rate of nitrogen fertilizer to the yield, reducing residues and losses of N in soil. Therefore the measurement should be recommended in the cold area tested.