Subsurface Irrigation

1. Filtered, pressure-regulated water is fed into buried mainline and lateral tubing
2. Inline emitters spaced along the buried laterals release water slowly at a controlled rate
3. Water moves through the soil to wet a zone around the buried line, reaching nearby roots
4. The surface generally remains dry, in contrast to surface-laid drip or overhead methods

Subsurface drip irrigation is used for a range of row crops, including maize and cotton, and for some perennial and horticultural plantings, particularly where reducing surface evaporation, freeing the surface for other field traffic, or extending equipment life by avoiding surface exposure to sunlight and machinery is valuable.

Because water is placed at or near the root zone with a dry soil surface above, subsurface drip irrigation can achieve high application efficiency, with generally lower direct evaporation loss than surface or overhead wetting. As with any localized system, the actual efficiency achieved depends on correct design, scheduling to crop water need, and system maintenance.

With the soil surface left dry, subsurface drip irrigation can reduce direct evaporation loss and, by delivering water and fertigated nutrients close to the root zone in controlled doses, can support more efficient nutrient use than broader surface wetting.

Keeping the surface dry also means field traffic, cultivation, and harvest operations can proceed without disturbing tubing that would otherwise be exposed on the surface, which can extend the system’s working life relative to surface-laid drip lines.

Because the tubing is buried, leaks, clogging, or root intrusion into emitters can be harder to detect than with surface drip systems, making water-quality management, filtration, and periodic system checks (such as flow monitoring) particularly important. Installation also requires specialised equipment to bury tubing at a consistent depth, and repairs generally require excavation.