The presence of surface competing cations and pH are expected to have an influence on the cation adsorption-desorption behavior of soils. In this study, we evaluated the adsorption-desorption behavior of K+in the presence of solution Ca2+(binary) or in the presence of solution Ca2+plus NH4(ternary) and the adsorption-desorption behavior of NH+4in the presence of solution Ca2+(binary) or in the presence of solution Ca2+plus K+(ternary). The soils selected for the study were the Eden, Lowell, and Nicholson soils from Northern Kentucky. These soils are generally known to give poor yield response to fertilizer application. It was shown that potassium adsorption was suppressed by solution NH+4while NH+4adsorption was greatly enhanced by solution K+. Adsorption of K+and NH+4also increased as pH increased. Ammonium desorption, on the other hand, decreased in the presence of solution K+relative to that in the absence of solution K+, increased at the medium pH tested, but decreased at the highest pH tested. Furthermore, in general, fixation accounted for most of the adsorbed K+or NH+4. The results suggested that-predicting exchange or apparent fixation behavior of monovalent cations based on ion size and charge for soils containing vermiculite type minerals is difficult. Experimental exchange data are needed to make accurate binary or ternary cation exchange predictions in such soil systems