|Camp Jr, Carl|
Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/22/1998
Publication Date: N/A
Interpretive Summary: Drip irrigation development began with availability of plastics following World War II. On-farm use of drip irrigation on the soil surface and refinement of various system components occurred in Israel during the next two or three decades. Subsurface drip has been part of drip irrigation development in the USA since its beginning about 1960, but its use has accelerated since 1980 with availability of reliable equipment. Published research results show that yields of over 30 crops with subsurface drip are equal to or greater than other irrigation methods, including surface drip, and usually require less water. The drip tubes may be installed 2 to 70 cm deep and 0.25 to 5 m apart, depending primarily upon the crop. One advantage of subsurface drip is that the tubes remain in the soil for 10 years or more, provided the tube does not interfere with any required tillage. The longer system life is critical to making the operation profitable. Nutrients and pesticides are easily applied to crops by injecting them into the irrigation system as frequently as required. Proper system design and management are critical and include good water filtration, water treatment if necessary, frequent system flushing to remove particles, and preventing roots from plugging the system emitters. These systems can use wastewater, including water from home sewage treatment systems, to irrigate home and commercial lawns and landscapes. Overall profitability depends on local conditions.
Technical Abstract: A comprehensive review of published information on subsurface drip irrigation was performed to determine the state of the art on the subject. Subsurface drip irrigation has been a part of drip irrigation development in the USA since its beginning about 1960, but interest has escalated since the early 1980s. Yield response for over 30 crops indicated that crop yield for subsurface drip was greater than or equal to that for other irrigation methods, including surface drip, and required less water in most cases. Several irrigation scheduling techniques, management strategies, crop water requirements, and water use efficiencies were discussed. Injection of nutrients, pesticides, and other chemicals to modify water and soil conditions is an important component of subsurface drip irrigation. Uniformity measurements and methods, assessment of root intrusion, and estimates of system life were also discussed. Sufficient information exists to provide guidance on design, installation, and management of these systems. Relative advantages and disadvantages of these systems are compared with those of other systems. Subsurface drip is more efficient than other systems if water and nutrient applications are managed properly. Wastewater application, especially for turf and landscape plants, may offer great potential. Profitability and economic aspects have not been determined conclusively and will depend on local conditions and constraints, especially availability and cost of water.