This paper outlines a combined system for solar desalination and irrigation/drinking water production, where the ground acts as a condenser for humid air flowing inside a system of buried
pipes. In the irrigation system, the condensed freshwater is supplied directly in the root-zone
through perforations in the pipe walls. This subirrigation scheme minimizes crop water consumption and eliminates water losses, such as surface runoff and evaporation. By moderating daily water distribution, the risk of land degradation is reduced, since salt transport to the topsoil by a rising groundwater table is prevented. The perforations also allow the irrigation system to be a drainage system that effectively removes excess soil water from the field. This analytical study is, however, mainly concerned with condensation of humid air in pipes without perforations. The condensed water may instead be collected at the pipe endings and used for drinking.