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

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 52.5 mg·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 17.5 mg·kg-1 low phosphorus treatment which suggested that A. fruticosa responded to low phosphorus stress through maintaining large proportion of roots. Phosphorus level of 52.5 mg·kg-1 was the optimal soil phosphorus concentration for the growth of A. fruticosa. A. fruticosa could grow well in the soils with low phosphorus content.