Changes in the water content of sandy and loamy sandy soils mulched with apolyethylene film to prevent evaporation upon model irrigation

The water content in the profile of sandy soils irrigated with excessive wa ter (to determine the field water capacity within the 2-m layer) and protec ted from evaporation by a polyethylene film remained very unstable within t he period of measurements (15 days). Changes in the water content of a part icular soil layer had different signs; however, the probabilities of an inc rease (or decrease) in the water content were different for different layer s. It is argued that the rise in soil water content is often connected with the process of condensation. This is proved by the absence of a correspond ing decrease in the water content of the upper soil layers.