Abstract:

The contents of different phosphorus forms in soils of waterlevelfluctuating zone at the estuary of the Maixi river，a tributary of the Baihua Reservoir,were studied using the standard measurement and test (SMT) procedure of phosphorus forms．Correlation coefficient between phosphorus forms and organic matter and pH was analyzed．The results indicated that the total phosphorus (TP) average contents in the soils of A zone was 1 2988 mg/kg， 1 1712 mg/kg in soils of B zone and 1 0762 mg/kg in soils of C zone．The TP content in the soils of A zone was the highest，and the soils of C zone was the lowest．Distribution characteristics of phosphorus forms were different between the soils of A zone，B zone and C zone.The ratio of OP/TP in the C zone (average value 633%) was higher than that in the soils of B zone(average value 607%)，and that in the soils of A zone(average value 592%) was the lowest.The dominant phosphorus forms of IP was Fe/AlP．The average ratio of Fe/AlP /IP was 789%in the A zone,was 642% in B zone, and 54.6% in C zone．The CaP average content in C zone was 1011 mg/kg,which was higher than that in soils of B zone (average content 849 mg/kg) and A zone (621 mg/kg).The average ratio of active phosphorus (OP+ Fe/Al-P) in TP was 738% in soils of A zone and 744% in soils of B zone, whereas the average ratio in soils of C zone was 771%．The active phosphorus would become potential pollution sources of water under appropriate environmental condition，therefore，the potential impact of phosphorus on water eutrophication in soils of waterlevelfluctuating zone could not be neglected