The study is to examine the effect of two soil amendments, namely, Sodium Silicate (Na2SiO3) and Diammonium Hydrogenphosphate ((NH4)2HPO4) on slopeland soil from Tsaotun. The soil was treated with different 0%, 0.1%, 0.5%, and 1.5% concentrations of Si and P. The treated soil samples were stored in plastic bags indoor for 6 months before subjecting them to the fertility with miscible displacement model. The results of the experiment indicated that the K breakthrough curves shifted to the right as the soil samples are treated with Na2SiO3 and (NH4)2HPO4, and V/V0 increased with increasing concentrations of Si and P. The effect of ion adsorption and CEC can be increased as soils treated Na2SiO3 and (NH4)2HPO4. (NH4)2HPO4 has the marked effect.