Domestic Subsurface Irrigation
Domestic Subsurface Irrigation Systems
Subsurface Drip Irrigation (what is it)
Domestic Subsurface drip irrigation better knows as (SDI) applies water to the root zone of the turf using buried polyethylene tubing.
The drip tube comes in different diameters in order to maintain acceptable irrigation uniformity. Smaller tube like 13mm is used for short runs up to 60 meters in domestic subsurface systems. Where 16mm is used mainly for commercial subsurface irrigation applications.
The main advantage of subsurface irrigation over other types of irrigation is that it is more efficient. I order to archive this it must be properly designed, installed and managed. Only then it can be more efficient than other forms of irrigation.
The aim of the irrigation system is to apply the water efficiently to the root zone. Therefore the depth of burial is determined by the root zone depth. some water from the emitter will travel upwards (by capillary action), some sideways, but the majority of water will travel downwards (under gravity).
The drip tube installed below the root zone will waste the majority of water it applies. Drip tube installed too close to the surface runs the risk of water ‘breaking” through to the surface.
This will cause uneven evaporation losses (in-efficient watering) and promote weed growth and lawn diseases.
Soil Type Line Spacing Drip Spacing Depth
Medium Sand 30cm 30cm 100mm
Loam 30cm 30cm 100mm
Clay Loam 40cm 40cm 100mm
Incorrectly Installed Tube
Domestic subsurface irrigation installed like this will only encourage shallow roots and runs the high risk of water breaking through the surface.
Drip-line Placement from Edges:
Consideration of drip-line location is necessary when laying out zone edges. Hardscape materials act as heat collectors and cause turf edges to dry out before the center of the turf, making it essential to compensate by placing the first drip-line no more than 50mm -100mm from the turf edge.