氮磷添加对高寒区老芒麦种子生产的影响OA

To evaluate the effects of nitrogen(N)and phosphorus(P)fertilization on seed yield and yield components of Elymus sibiricus in alpine regions,the cultivar'Qingmu 2'was used as the experimental material.Four N levels(N0:0 kg N/hm2,N1:60 kg N/hm2,N2:90 kg N/hm2,N3:120 kg N/hm2)and four P levels(P0:0 kg P2O5/hm2,P1:30 kg P2O5/hm2,P2:60 kg P2O5/hm2,P3:90 kg P2O5/hm2)were established to assess seed yield and yield components,and economic returns.The results showed that under combined N and P application,spikelet number per reproductive tiller,seed number per spike,spike length,thousand seed weight,and seed yield of E.sibiricus first increased and then decreased with the increasing P application rate.Among all treatments,N1P2(60 kg N/hm2+60 kg P2O5/hm2)showed the best overall performance,with a seed yield of 1 654.69 kg/hm2,representing a 74.8%increase over the unfertilized control.The corresponding economic return reached 12 074.41 CNY/hm2.Structural equation modeling indicated that the positive effect of N and P fertilization on seed yield was mainly mediated through an increase in tiller number.Comprehensive evaluation using the Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)identified N1P2 as the optimal fertilization regime for E.sibiricus seed production in alpine regions.These findings provide a theoretical basis and technical support for effi-cient seed production of E.sibiricus in alpine regions.