Irrigation Strategies Utilizing Subsurface Drip Irrigation.

Subsurface drip irrigation (SDI) is practiced on approximately 60,000 ha in the Texas High Plains region of the USA. Adoption of SDI continues to increase in the region. This has been attributed to record drought in Texas and the US Southwest in recent years, declining irrigation well yields, and evidence that SDI results in reduced evaporative losses and greater partitioning of evapotranspiration to crop transpiration compared with other irrigation methods. These factors result in greater crop water productivity, reduced evaporative cooling, and warmer soil temperatures near the surface, which is critical for cotton plant establishment where heat units are limited. Despite increased SDI adoption, it is still only 3 percent of the irrigated area in the region. Barriers to SDI adoption include larger capital costs, different management practices, and difficulty in crop germination when early season precipitation is lacking. Efforts aimed at reducing these barriers have included government cost share programs, education programs for producers on irrigation management, and research on alternative SDI designs and tillage practices, respectively. Continued adoption of SDI in the region suggests that these efforts may be having impact, but adoption could nonetheless be accelerated by converting the remaining gravity-irrigated land and replacing aging center pivot systems with SDI.