US Patent 6959882 Watering and aerating soil with a drip line

When the dripline used for watering soil, low pressure air in the range 10–100 inch water column is flowed through a buried dripline, in alternation of with flow of water at 5 psig or more. The flow of air provides oxygen to the soil, and more widely and evenly disperses the water within the soil, and impedes or counters saturation. A buried dripline runs in a U-shape path, so that low pressure and flow of air from emitters near the dripline terminal end is compensated for by higher pressure and flow of air near the inlet end. Flow of low pressure air or other gas, which pushes water from the dripline and surrounding soil, enables use of driplines in soil subject to freezing.