半湿润农田生态条件下施氮对不同冬小麦品种氮素转移的影响

在年均降水量632mm的黄土高原南部半湿润红油土上进行田间试验,以NR.94059、430、偃师9号、小偃6号、陕229、西农2208、矮丰3号和商188为供试材料,研究在不施氮和施氮(N.90.kg/hm2)条件下不同冬小麦品种灌浆期氮素转移的差异。结果表明,小麦氮转移量(NT)和氮转移效率(NTE)在不同品种间差异不显著,而茎鞘氮转移效率(NTES)在品种间存在显著差异(P0.05),施氮对这些指标没有显著影响。转移氮对子粒氮贡献率(NCR)在不同品种间差异显著(P0.05),而施氮对NCR没有显著影响。不同品种间NCR从大到小的顺序为NR9405、西农2208、矮丰3号、商188、偃师9号、9430、小偃6号、陕229。氮收获指数(NHI)具有显著的品种差异,NHI从大到小的顺序为陕229、9403、矮丰3号、西农2208、偃师9号、商188、NR9405、小偃6;陕229和9403的NHI超过80%,分别为81.76%和81.02%;小偃6号仅为76.62%。不同品种的氮素利用效率(NUE)存在极显著差异(P0.001),以偃师9号最高,为37.25.g/g,小偃6号最低,为29.29.g/g;施氮对NHI和NUE无显著影响。子粒含氮量与NUE间呈极显著负相关关系(r=0.918,P0.001),表明对同一个品种难以同时提高NUE和子粒含氮量。

Effect of N fertilization on N translocation of different winter wheat cultivars during grain filling period in sub-humid farmland ecologic system

A field experiment was carried out on a Hongyou soil located in the south part of loess plateau with annual precipitation being 632mm. Eight winter wheat cultivars, named NR 9405, 9430, Yanshi No.9, XiaoyanNo.6, Shan 229, Xinong 2208, Aifeng No.3 and Shang 188, were used as indicating crops to study the effects of N fertilization on nitrogen translocation at grain filling period. The results showed that there were no significant difference on nitrogen translocation (NT), nitrogen translocation efficiency (NTE) between different cultivars,however, nitrogen translocation efficiency on haulm and contribution of transfer nitrogen to grain (NCR) showed a significant variation between different cultivars (P<0.05). Results also showed that N application had no effect on those index. NR 9405 had the highest NTE being 76.65%, while Shan 229 was lowest which was 66.82%. Nitrogen harvest index(NHI) of Shan 229 was the highest, followed by NR 9403, Aifeng 3, Xinong 2208, Yanshi 9, Shang 188, NR 9405 and Xiaoyan No.6 sequentially. There was a significant difference on NUE between different cultivars (P<0.001), among which Yanshi 9 was the highest being grain 37.25 g/g N, and Xiaoyan No.6 was the lowest being grain 29.29g /g N. NHI and NUE was not changed with the N application. There was a significant negative correlation between N content in grain and NUE which indicated that it was impossible to increase NUE and grain nitrogen concentration simultaneously as to one variety.