不同供磷水平对紫穗槐生长及根系形态的影响

Effects of phosphorus fertilizing on growth and root morphology of Amorpha fruticosa

以紫穗槐(Amorpha fruticosa)为材料,利用土培法研究不同供磷水平对其植株生长和根系形态的影响,以期为在黄土高原确定适宜的建植地区及建植过程中合理的磷肥施用量奠定基础。结果表明,52.5mg·kg-1供磷水平下,紫穗槐植株株高、地径、总生物量、地上部及根系生物量均最大,叶片生长良好;根系平均直径、根系总长、根系总表面积和总体积最大,根系发育最好。17.5mg·kg-1低磷水平下,根冠比最大,通过维持较大比例的根系来响应低磷环境。供磷水平过低或过高对紫穗槐生长均产生不利影响,52.5mg·kg-1是紫穗槐生长的最适土壤磷浓度。紫穗槐对土壤磷素水平要求较低,能够在较为贫瘠的土壤中生长良好。

The soil culture experiments were employed to study the effects of different phosphorus levels on the growth and root morphology of Amorpha fruticosa,and provided the reference for the determination of the suitable planting areas and phosphorus application in the Loess Plateau region.The results showed that the growth of leaf and the development of root were the best with 52.5mg·kg-1 phosphorus treatment based on the results that both the characters of plant growth,including plant height,ground diameter,total biomass,shoot and root biomass,and characters of plant root morphology,including average diameter,total length,total surface area and total volume were the largest.The root-shoot ratio reached the largest with 17.5mg·kg-1 low phosphorus treatment which suggested that A.fruticosaresponded to low phosphorus stress through maintaining large proportion of roots.Phosphorus level of 52.5mg·kg-1was the optimal soil phosphorus concentration for the growth of A.fruticosa.A.fruticosa could grow well in the soils with low phosphorus content.