Movement of NH3plus NH4+from nitrogen fertilizers, band placed either as crystals or as granules in alkaline soils, was determined. The pH values of these soils, whereof the clay contents ranged from 7,6 to 49,9%, were adjusted to approximately 8,8. Fertilizers like (NH4)2SO4, LAN, urea, MAP and DAP were band placed in these soils with different water contents at different bulk densities. The application level was equivalent to 60 kg N ha−1. After a contact period of 14 days the movement of NH3plus NH4+was determined. The distances that NH3plus NH4+moved from the plane of application varied between 45 and 100 mm. The results indicate that the movement of NH4+was small compared to the movement of NH3. The major factor that controlled the degree of NH3movement in soil was the quantity of NH4+converted to NH3. The conversion of NH4+to NH3was governed by the variable soil properties and the type of fertilizer. Both diffusion and convection contributed to the movement of NH3.