Abstract: Aiming to the Hetao irrigation area’ s current situation of long-term excessive application of chemical fertilizer and less application of organic fertilizer,this paper discussed the effect of replacing chemical fertilizer nitrogen with organic fertilizer nitrogen on the growth and development,nitrogen efficiency and yield of spring maize,which provided the theoretical basis for exploring the feasibility of combining chemimal fertilizer nitrogen reduction and organic fertilizer nitrogen application in Hetao irrigation area and the proportion of fertilizer reduction.The effect of replacing chemical fertilizer nitrogen with organic fertilizer nitrogen on the growth and development,nitrogen efficiency and yield of maize in Hetao irrigation area of Inner Mongolia was discussed by using field experiments,and by setting up five fertilization models of no nitrogen fertilization(CK),farmers’ conventional fertilization(CF),reduced fertilization(TS),replacing 30% fertilizer nitrogen with organic fertilizer nitrogen on the basis of TS(MF),and replacing 50% fertilizer nitrogen with organic fertilizer nitrogen on the basis of TS(OF).The result revealed that the nitrogen fertilizer application could speed up the maize growth,and the method of replacing fertilizer nitrogen with organic fertilizer nitrogen(MF,OF) was more effective in promoting the growth of maize. In tasseling stage,the leaf area indexes of MF and OF treatments were the highest,which were 60.4%,11.1%,35.6%,and 60.1%,10.9%,35.3% higher than that of CK,CF and TS respectively.In mature period,the OF treatment’s dry matter accumulation was the highest,which was 2.6 times of CK,and was 45.1%,43.0% and 57.7% higher than that of CF,TS and MF treatments respectively.Under the condition of same N application,the nitrogen efficiency and yield of maize could be improved more by replacing chemical fertilizer nitrogen with organic fertilizer nitrogen than only applying chemical fertilizer nitrogen(TS treatment). In terms of photosynthetic characteristics of maize,the effect of MF treatment was more obvious.The yields of MF and OF treatments were not significantly different from that of CF treatment.But the outputs of MF and OF treatments were 162.1% and 161.7% higher than that of CK treatment,32.6% and 32.4% higher than that of TS treatment respectively.The results of comprehensive analysis showed that the growth rate,leaf area index,photosynthetic characteristics,nitrogen efficiency and yield of maize could be significantly improved by replacing part of chemical fertilizer nitrogen with organic fertilizer nitrogen under the same amount of nitrogen application.Replacing 50% chemical fertilizer nitrogen with organic fertilizer nitrogen was a reasonable way of increasing the yield of spring maize and increasing the efficiency of nitrogen fertilizer in Hetao irrigation area of Inner Mongolia.

Key words: Spring maize, Organic fertilizer N, Chemical fertilizer N, Growth rate, Leaf area index;Photosynthetic characteristics, Nitrogen efficiency, Yield, Hetao irrigation area

摘要： 针对河套灌区长期过量施用化肥而较少施用有机肥的现状，探讨了有机肥氮替代化肥氮对春玉米生长发育、氮素效率及产量的影响，为探讨河套灌区化肥氮减量与有机肥氮配合施用的可行性及化肥减量比例提供理论依据。采用田间试验，设置不施氮肥（CK）、农民常规施肥（CF）、减量施肥（TS）、TS基础上有机肥氮替代30%化肥氮（MF）、TS基础上有机肥氮替代50%化肥氮（OF）5种施肥模式，探讨了内蒙古河套灌区有机肥氮替代化肥氮对春玉米生长发育、氮素效率及产量的影响。结果表明，施用氮肥可以加快玉米的生长速度，以有机肥氮替代化肥氮（MF、OF）对玉米生长的促进效果更明显，抽雄期MF、OF处理叶面积指数达到最高，分别较CK、CF、TS处理高60.4%、11.1%、35.6%，60.1%、10.9%、35.3%，成熟期OF处理干物质积累量最高，为CK的2.6倍，并分别比CF、TS、MF处理高45.1%、43.0%、57.7%。相同施氮量下，有机肥氮替代化肥氮比单施化肥氮(TS处理)更能提高玉米的氮素效率及产量，且MF处理提高玉米光合特性的效果较明显。MF、OF处理产量与CF处理没有明显差异，但较CK分别提高162.1%、161.7%，较TS处理分别提高32.6%、32.4%。综合分析，相同施氮量下，有机肥氮替代部分化肥氮能明显提高玉米生长速度、叶面积指数，改善光合性能，提高氮素效率及产量，有机肥氮替代50%化肥氮为内蒙古河套灌区春玉米增产、氮肥增效的合理施肥方式。

关键词: 春玉米, 有机肥氮, 化肥氮, 生长速度, 叶面积指数, 光合特性, 氮素效率, 产量, 河套灌区