Dynamic change of salt contents in rhizosphere soil of salt-tolerant plants Effect of crop rotation on ion accumulation in secondary salinization soil of vegetable field in greenhouse Dynamics of soil salt content in the rhizosphere soils of four salt-tolerant forage species Study on the soluble salt ions contents of Populus alba L.var.pyramidalis growing in salinity soils Protection effect of salt damage by coastal windbreak forest Salt absorption capacities of several annul halophytes