江华国家烟草示范基地土壤磷的吸附与解吸特征

Characteristics of Sorption and Desorption of Phosphate by Soil in Jianghua National Tobacco Demonstration Base

采用恒温培养法研究了湖南永州江华国家烟草示范基地土壤的磷吸附和解吸特性。结果表明,土壤的磷吸附曲线与Langmuir、Freundlich及Temkin等温吸附曲线均达到极显著相关水平,以Langmuir方程的拟合度最高。土壤最大吸附磷量与pH值呈极显著负相关,与有机质呈显著正相关。3个供试土壤磷的最大吸附量(Xm)在1 428.6～2 500.0 mg/kg之间,吸附亲和力常数(K)值介于0.135～0.212之间,磷的最大缓冲容量(MBC)值介于270.3～454.5 mg/kg之间,磷的吸附饱和度(DPS)值介于0.93%～1.67%。随磷的吸附量的增加,解吸量有增加的趋势。

The characteristics of sorption and desorption of phosphate by soil were investigated in Yongzhou Jianghua national tobacco demonstration base under the condition of constant temperature.The results indicated that all phosphate adsorption curves could be well described by Langmuir,Freundlich and Temkin equations with best fitness by Langmuir equation.The maximum amounts of phosphate adsorption by soils were significantly negative correlated with pH,and significantly positive correlated with soil organic matter.The maximum P sorption capacity（Xm） was from 1 428.6 to 2 500.0 mg/kg,constant of P sorption bonding energy（K） was from 0.135 to 0.212;the maximum buffering capacities（MBC） were from 270.3 to 454.5 mg/kg,and degree of P sorption saturation（DPS） was from 0.93% to 1.67%.The phosphorus desorption had increase tended with the increasing phosphorus adsorption.