Abstract: The split-plot experiment was designed to study the effects of different nitrogen and phosphorus application rates on seed yield, yield components and root growth in different growing stages of Elymus sibiricus in Hebei Province. Results indicated that nitrogen fertilizer application affected thousand- seed weight significantly (P<0.05). Seed yield reached the highest rate of 592.26 kg穐m^-2 with 90 kg N穐m^-2 nitrogen fertilizer application. When the phosphorus fertilizer application was 90 kg P穐m^-2, seed yield reached the highest rate of 680.61 kg穐m^-2. The phosphorus fertilizer improved seed yield by affecting the amount of tillers per unit area, fertile tillers per unit area and spikelets per inflorescence. Without nitrogen and phosphorus fertilizer application, both total length and surface area of root are high while increasing nitrogen and phosphorus fertilizer applications initially decreased then increased both total length and surface area of root initial. Nitrogen fertilizer alone had no significant affect for average root diameter. Root growth was faster from seedling establishment to heading stage and reached its peak in seed maturation stage.

Key words: Elymus sibiricus L, Nitrogen, Phosphorus, Yield components, Seed yield, Roots

摘要： 试验采用裂区设计,研究不同氮磷处理对老芒麦(Elymus sibiricus L.)种子产量组分、产量以及对不同生育期老芒麦根系生长的影响。结果表明:施90 kg N·hm^-2时,种子产量达到最高为592.26 kg·hm^-2,氮肥对千粒重影响显著(P<0.05);施90 kg P·hm^-2时,种子产量达到最大为680.61 kg·hm^-2,磷肥主要通过影响分蘖数、生殖枝数和小穗数来提高产量;氮磷互作对千粒重影响显著(P<0.05)。不施肥时总根长和根系表面积根生长处于较高的水平,随着施氮量和施磷量的增加,根表面积和总根长均先减小后增加,氮肥对老芒麦根平均直径无显著影响;返青期至抽穗期根系生长速度较快,成熟期达到最大值。

关键词: 老芒麦, 氮肥, 磷肥, 种子产量组分, 产量, 根系