Sub-irrigation

The watering of a turf from below the surface. This may typically be achieved through buried drip-feed irrigation pipe or perforated drainage-irrigation pipes, which are located just below the normal depth of root growth. Water would typically seep sideways and upwards by capillary action and downwards by drainage. The accumulation of salts can be a problem by sub-irrigation, especially if the rootzone is not periodically flushed of salt build-up.