Effects of Nitrogenous Fertilizer and Phosphorus Fertilizer Applications on Roots and Seed Yield of Elymus sibiricus

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.