磷添加对早熟禾叶片化学计量特征和养分重吸收效率的影响OA

In this study,Poa pratensis var.Qinghai was used as the research subject.The changing trends in leaf stoichiometric ratios and nutrient resorption efficiency under six phosphorus(P)addition levels(30,45,60,75,90,and 105 kg·hm-²,sequentially labeled as P1,P2,P3,P4,P5,and P6)were investigated.The results indicated:(1)The leaf carbon(C),nitrogen(N),and P contents generally exhibited the pattern of senescent stage<full ripeness stage<milky ripeness stage,with the highest accumulation of leaf nutrient con-tents observed under the P3 level.(2)Leaf C/N and C/P ratios generally followed the pattern of senescent stage>full ripeness stage>milky ripeness stage,while the N/P ratio generally showed full ripeness stage>milky ripeness stage>senescent stage.(3)The Nitrogen Reabsorption Efficiency(NRE)was the highest under the CK(control,no P addition)treatment,whereas the Phosphorus Reabsorption Efficiency(PRE)was the highest under the P2 addition level.(4)A generally positive correlation was observed between leaf NRE and stoichiometric ratios,while PRE exhibited a generally negative correlation with stoichiometric ratios in mature leaves and a generally positive correlation with stoichiometric ratios in litter leaves.This study suggests that the appropriate P addition amount is P2-P3(45～60 kg·hm-2).This research provides practical guidance for precision fertilization and scientific management of artificial grasslands in alpine regions.