Cattle and pig dung and poultry excreta were used in laboratory experiments to study the effect of different solid manure treatments concerning NH3 losses during storage and after application to soil. Aerobic decomposition (composting) during incubation (storage) resulted in drastically higher NH3 emissions compared with anaerobic decomposition conditions. Application of the aerobically treated materials to soil resulted in low NH3 losses, as NH4-N concentrations were low in these materials. Anaerobically treated materials and non-decomposed poultry excreta gave rise to significant NH3-N emissions as a result of highly increased ammoniacal N concentrations in soil, if applied on the soil surface. Rates of NH3-N volatilization from soil surface-applied manures were closely related to the pH changes taking place on the surface. Maximum pH values attained explained 79% of the variance in the extent of NH3 volatilization. Incorporation of animal dung into soil to 5 cm depth or below reduced ammonia volatilization by 80% compared with surface application.