秋播高羊茅生长、生理特性及氮需求对氮肥用量的响应OA

[Objective]To clarify the effects of nitrogen(N)fertilizer application on the growth,physiological characteristics,and nutrient absorption of autumn-sown tall fescue(Festuca arundinacea),and to determine the ap-propriate N application rate and N nutrition diagnosis index.[Method]A field micro-plot experiment was conducted to evaluate the responses of the shoot growth,physiological characteristics,N,phosphorus(P)and potassium(K)up-take,and N use efficiency of F.arundinacea to different N fertilizer application rates(0,6,12,18 g/m2)during the overwintering and regreening stages.[Result]Appropriate application of N fertilizer could improve the chlorophyll content,nutrient concentrations,and uptake of F.arundinacea,leading to increased plant height,leaf number,and til-ler count,thereby promoting the growth of the above-ground part.With the increase of N application rate,the content of soluble protein,soluble sugar,and proline increased,and the content of malondialdehyde decreased,which was ben-eficial to enhance the resistance of plants to low-temperature stress and reduce the damage of low temperature.When the amount of N fertilizer was 12 g/m2,the apparent N use efficiency was the highest,which was 36.76%.The suit-able N fertilizer application range for F.arundinacea growth was 6.5～30.2 g/m2,and the critical N concentration for 80%of the maximum shoot dry matter accumulation was 2.95%.[Conclusion]Nitrogen fertilizer application significantly affects the growth and physiological characteristics of F.arundinacea.Nitrogen fertilizer application rate of 6.5 g/m2 and the N concentration of 2.95%in plant shoot can be used as N fertilizer recommendation and plant N nutrition diagnosis for maintenance and management of F.arundinacea.