Submitted to: International Congress on Irrigation and Drainage
Publication Type: Proceedings
Publication Acceptance Date: 2/1/2005
Publication Date: 8/21/2005
Citation: Clemmens, A.J. 2005. Raising the performance of surface irrigation. International Congress on Irrigation and Drainage. p. Q.52,P.1.06.
Interpretive Summary: Irrigated agriculture uses about 60% of the freshwater diverted for use in the United States, with surface irrigation used on about half of the irrigated land. Yet surface irrigation has a reputation for poor performance. This paper discusses the reasons for poor surface irrigation performance and methods to overcome these limitations. Examples are provided where significant improvements in surface irrigation performance have been made. Laser-guided land grading is an important technology for improving performance. New methods of laying out irrigation systems and land shaping are providing new options for improving performance, even on traditional contour rice paddies. This information should be useful to irrigation farmers, the Natural Resources Conservation Service, extension specialists, and agricultural consultants.
Technical Abstract: Surface irrigation systems often have a reputation for poor performance. One key feature of efficient surface irrigation systems is precision (e.g. laser-guided) land grading. Poor land grading can make other improvements ineffective. An important issue, related to land shaping, is developing the proper layout for guiding water to individual bays and the appropriate sizing for individual bays based on soils and flow rate. A number of methods have recently been developed that have potential to improve water control, increase yields and improve irrigation efficiencies for rice, some of which may have world-wide application. Control of flow rate is another important feature of efficient surface irrigation. A good, efficient design and layout is less sensitive to fluctuating flows, but performance can degrade when flows are too low. The use of farm reservoirs and farm wells can be used to reduce the impact of poor water delivery service from irrigation water purveyors. Examples are provided of surface irrigation systems and projects where significant improvements in water management have resulted in less water diverted, higher yields, reduced labor costs, etc. These are the direct result of better on-farm water control, uniform irrigation, effective surface drainage, and effective rainwater capture. These approaches, when adapted to local topographic and climatic conditions, can provide significant improvements for intermittently-irrigated crops, as well as for rice.