广东省主要母质发育水稻土对磷的吸附特性

对广东省5种不同母质上发育的水稻土进行了P素等温吸附试验.结果表明,供试土壤的等温吸附数据与Langmuir、Freundlich和Temkin 3个方程都能很好地拟合,但以Langmuir方程拟合程度最好(相关系数从0.995^**到0.999^**).利用Langmuir方程计算的P最大吸附量(Xm)和吸附强度因子(K)的乘积(KXm:P吸附特性值)可以作为水稻土吸附P素的综合指标,KXm的大小可以表明水稻土施P次序.试验结果还表明供试水稻土对P素吸附存在两种不同的吸附区.

Phosphate adsorption characteristics of paddy soils derived from main parent materials in Guangdong Province

Isothermal adsorption experiment of phosphate on paddy soils drived from five different parent materials in Guangdong Province was carried out. The result showed that the adsorption data of different test soils could be simulated well by Langmuir, Freundlich and Temkin equations, and the Langmuir equation fitted the data best (correlation coefficient r: 0.995-0.999..). As a value of phosphate adsorption characteristics, the product of phosphate adsorption maximum (Xm)and sorption intensity factor(K) calculated by Langmuir equation could be a comprehensive index to characterize the potential phosphate adsorption by paddy soil, and could indicate the order of applying phosphate. The result also indicated that there exists two types of sorption region on the soils tested.