Abstract: A split-plot experiment was designed with different nitrogen fertilizer and phosphorus fertilizer application in the seed field of Elymus sibiricus L.growing in the Hebei Province.Yield components,seed yield and total root length,total surface area,average diameter and total volume during different stages of Elymus sibiricus were measured to determine optimum treatment of the highest yield and the relationship between root vegetation and seed yield.Results indicated that phosphorus fertilizer application affected both tiller number and fertile tiller number per unit area.Nitrogen fertilizer application affected thousand seed weight.Combined application of phosphorus and nitrogen fertilizer improved the amount of florets per tiller and seed yields per tiller.Under low nitrogenous fertilizer,Elymus sibiricus increases nitrogen uptake by increasing its total root length,root surface area,average diameter and total volume,while nitrogen absorption is plentiful,root growth continues.Root reaction for phosphate fertilizer is similar to that for nitrogenous fertilizer,but root growth is inhibited when phosphate fertilizer is further increased.There is no significant correlation between root and seed yield.

Key words: Siberian wildrye, Nitrogen, Phosphorus, Yield components, Seed yield, Root

摘要： 试验采用裂区设计,通过不同氮磷处理,研究施肥对河北坝上老芒麦(Elymus sibiricus L.)种子产量组分、种子产量以及老芒麦不同生育时期总根长、根表面积、平均直径、总体积的影响,以期确定获得种子高产的最佳施肥处理,并明确根系与种子产量的关系。结果表明:磷肥的效果主要与单位面积分蘖数、单位面积生殖枝数的变化有关;氮肥的效果则主要与千粒重的变化有关;每小穗小花数、每小穗种子数影响实际产量是氮磷共同作用的结果;氮肥不足时,老芒麦通过增加根系总根长、根表面积、平均直径和总体积来增大吸氮量,氮肥充足时,可进一步促进根系生长;根系对磷肥的反应相似,但当进一步增大施磷量时,根系生长受到抑制;根系与种子产量之间没有显著的相关性。

关键词: 老芒麦, 氮肥, 磷肥, 种子产量组分, 种子产量, 根系