Infiltration with controlled air escape

Infiltration into the soil is restricted if the movement of displaced air is hampered. In this study, separate infiltration experiments were performed where the air could escape only through capillary glass tubes (three different diameters were used). Control experiments, where the air movement was not restricted, were performed also. During the experiments both air pressure and the cumulative infiltration were measured. Air pressure measurements showed a rapid rise to a maximum after the water was ponded, followed by a gradual decrease. A first aim of this study was to show that even for a small increase in pressure relative to the case where the air was free to escape, e.g.,