Chemical behavior of heavy metals in rhizosphere Ⅲ. The rhizosphere effect of iron oxide transformation in soils and its ecological significance Phosphorus adsorption and desorption properties of three synthetic iron oxides and their relation to phosphorus adsorption saturation X-ray diffraction and fingerprint establishment of processed product of Haematitum X-ray diffraction and fingerprint establishment of processed product of Haematitum Phosphorus adsorption of iron oxideshumic acid compounds Changes of iron oxides and phosphorus adsorption-desorption in paddy soils under alternating flooded and dried conditions