The composition of clay minerals and adsorption characteristics on P

K

Cu

Zn

Pb of main orchard soils in Shandong province were studied.The results show that the composition of clay minerals was different between different soil types in Shandong main orchard soils.The kaolinite was the dominant mineral type in brown soils(Hap-Udic Luvisols) with high leaching and lower soil pH. This soil expressed a strong adsorption on phosphorus

but less or weak fixation on potassium.The availablity of phosphorus was relatively low for the Cao soils(Och-Aquic Cambosols) and cinnamon soils(Hap-Usdic Luvisols)

due to the high adsorption

high carbonate content and chemical precipitation action.Because Shajiang black soils(Cal-Aquic Vertosols) contained large amount of montmorillonite and 1.4 nm interlayer minerals

this soils displayed a strong adsorption capacity and crystal lattice fixation on potassium.Therefore

the availability of phosphate and potash fertilizers in Shajiang black soils were lower than that in brown soils.The adsorption ability and capacity on heavy metals of Cu

Zn

Pb in Shajiang black soils and Cao soils was significantly greater than that in brown soils and cinnamon soils

the dominant influence factors were the differences in clay content

clay mineral types and their composition among different soil types.The adsorption capacity on Pb was far greater than that on Zn and Cu in the same soils

which was mainly dependent on the chemical property of these elements and the adsorption characteristics of the colloids.