Infiltration Characteristics of Film Hole Irrigation Under Different Soil Salinity Levels

ABSTRACT With the increasingly severe shortage of agricultural water resources and the problem of land salinization, finding effective irrigation methods to improve soil conditions has become particularly important. The aim of this study was to investigate the effects of initial soil salinity on the infiltration characteristics of film hole irrigation. In this work, indoor soil box infiltration experiments were conducted to study the cumulative infiltration, the wetting front transport distance and the distributions of water–fertilizer–salt at the end of the infiltration process under film hole irrigation with clean water and muddy water with different salt contents. The results revealed that the higher the soil salinity was, the lower the cumulative infiltration per unit area, and the shorter the distance of wetting front transport. The greater the distance from the centre of the film hole was, the greater the soil electrical conductivity, and the lower the water content and nitrate nitrogen content. Compared with those under clean water irrigation, the desalination depth and horizontal desalination distance under muddy water irrigation were lower, and the salt ion content at the film hole was greater. The research results could provide a theoretical basis for further exploration of saline soil film hole irrigation.