施硅对水稻土磷素吸附与解吸特性的影响研究

Effect of supply silicon on adsorption and desorption action of phosphorus in paddy soil

研究了水稻土中施Si对P吸附与解吸特性的影响。结果表明 ,由于土壤中Si、P存在着竞争性吸附 ,当Si施入土壤时 ,它必然占据一部分Si、P共用的吸附点位 ,降低了土壤中P的吸附量。施Si对P解吸量的影响比较复杂 ,在低P浓度 (10、2 0、30mg/kg)时 ,施Si增加了P的解吸量 ;在高磷浓度 (40mg/kg)时 ,施Si后P的解吸量变化不大 ,而P浓度为 5 0mg/kg时 ,P的解吸量随Si的施加呈下降趋势。表明Si减少P吸附量的同时 ,也由于降低了土壤对P的吸附结合能 ,而增加了易解吸P的含量。

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