The order of Df (desorption factor) value was: yellowish red soil>silt-loamy soil>kaoline>perlite>paddy soil (loamy clay) >kieselguhr.

• 解吸因数的大小排列顺序为:黄红壤、粉泥土、高岭土、珍珠岩、青紫泥、硅藻土。