Abstract:In this paper, effect of supply silicon on adsorption and desorption action of phosphorus in paddy soil was studied The results showed that supplying silicon to the soil decreased the amount of adsorption for phosphorus because of competitive adsorption between silicon and phosphorus It was relatively complex that application of silicon affect phosphorus desorption Supplying silicon increased phosphorus desorption in 10,20 and 30 mg/kg phosphorus concentration, and phosphorus desorption hardly changed in 40 mg/kg phosphorus concentration, but supplying silicon decreased phosphorus desorption in 50 mg/kg phosphorus concentration This showed that application of silicon reduced phosphorus adsorption, and enhanced easily desorbed phosphorus content Supplying silicon improved phosphorus desorption rate in soil