广东省不同母质赤红壤磷的吸附与解吸

PHOSPHATE ADSORPTION AND DESORTION IN LATERITIC REDSOILS FROM DIFFERENT PARENT MATERIALS IN GUANGDONG

研究了广东省４种不同母质赤红壤磷的吸附与解吸特征,结果表明,４种不同母质赤红壤等温吸附方程(Ｌａｎｇｍｕｉｒ方程,Ｆｒｅｎｄｉｌｃｈ方程和Ｔｅｍｋｉｎ方程)的拟合结果都达到了极显著的水平．土壤吸附磷量由大到小的顺序为:玄武岩＞页岩＞花岗岩＞砂页岩．赤红壤对磷的解吸顺序为:玄武岩＜页岩＜花岗岩＜砂页岩,说明粘粒较少的母质土壤对磷的吸附力也小,因此,更容易解吸．提高土壤有机质的含量,可以改善土壤的供磷性能．

The phosphate adsorption and desorption in lateritic red soils from 4 parent materials in Guang-dong were studied in the paper. The results showed that the isothermal adsorption equations of Langmuir equations, Freundlich equations and Temkin equations perfectly modeled the processes of phosphate adsorption in lateritic red soils from 4 parent materials. H2PO4- adsorption capacity in the lateritic red soils was followed by the order of basalt > shale > granite > sandstone. H2PO4- desorp-tion capacity was in following order: basalt < shale < granite < sandstone. The lower the clay con-tent in lateritic red soils was, the smaller the phosphorus adsorption was, the easier the phosphate desorption was. Increasing the organic matter in the soils may improve the supply efficiency of phos-phorus .