磷添加对不同品种首蓿生物量及根系可塑性的影响

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中图分类号：S541 文献标识码：A 文章编号：1007-0435（2026）02-0392-11

Effects of Phosphorus Addition on Biomass and Root Plasticity of Different AlfalfaVarieties

FENG Zi-xuan，XU Zi-ying，MA Hong-yan， JING Jing-ying （College of Grassland Science and Technology，China Agricultural University，Beijing lOol93，China）

Abstract： To investigate the responses of alfalfa root morphological traits to phosphorus supply，a total of 31 plant materials were selected comprising 3O varieties of Medicago satiua L. and one variety of Medicago falcata L.，and three levels of phosphorus addition treatments were set up at P5（5mg⋅kg-1KH2PO4） ， Δ20（20mg⋅kg-1 KH2PO4） ，and P50 （ 50mg⋅kg-1KH2PO4） . To screen low phosphorus tolerant alfalfa varieties with high phosphorus use eficiency，we measured the aboveground and belowground biomass and root morphological indices for the 3l alfalfa varieties.The results indicated that theaboveground and belowground biomass of alfalfa were lowest under P5 treatment. With increasing phosphorus supply，the aboveground biomass of alfalfa significantly increased，reaching its highest level under the P50 treatment. Under the P20 and P50 treatments，the root biomass of alfalfa was significantly higher than that under P5 ，but there was no significant difference between P20 and P50 However， the root morphology showed significant variation among diferent varieties. Among them，‘HD' ‘Algonguin’‘Magna Graze I'’ and‘Longmu 8O1’ had higher biomass than other varieties，and exhibited greater root morphological plasticity with higher root length，root volume，root surface area，and root diameter，which demonstrated tolerance to low phosphorus condition.The results provide a scientific basis for opti mizing alfalfa cultivation and improving phosphorus fertilizer utilization effciency.

Key words： Phosphorus level;Alfalfa; Root morphology;Phosphorus-efficient varieties

苜蓿是一种多年生优质豆科牧草，因其蛋白含量高、产草量高而有着"牧草之王"的美称[1。（剩余19375字）