Phosphorus contents in the rhizosphere and bulk soil under Amorpha fruticosa established in different years

The rhizosphere and bulk soil of Amorpha fruticosa established in different years were studied.Available phosphorus(P),total P and P fractions were analysed using the method of Hedley which was a soil P classification method revised by Tiessen.Available P levels in the rhizosphere were higher than those out of the rhizosphere.The Y60 had the highest inorganic P content than the other except for H2O-Pi and Conc.HCl-Pi.The NaHCO3-Pi,NaOH-Pi,NaHCO3-Po,NaOH-Po,and Conc.HCl-Po in the rhizosphere were higher than those in bulk soil in different aged Amorphaexcept for NaHCO3-Po in Y28.Available P in the rhizosphere had a significant relationship with Dil.HCl-Pi and Conc.HCl-Po.H2O-Pi and total P had a significant relationship.Available P and pH in the rhizosphere and out of the rhizosphere did not have a significant relationship with total P in the rhizosphere.