An experimental study was carried out to clarify the effects of steady and fluctuating non-isothermal conditions on evaporation of homogeneous and structurally layered soil columns.It was found that there were differences in water losses by evaporation caused by the modes of the nonisothermal conditions and by the depth and aggregate size of the top soil layers. Optimal ranges of aggregate size and depth of the top layer were found.Field applications are discussed.