Irrigation Performance: An Evaluation

The efficiency and distribution of water of an irrigation can be described by the measurement of as few as four independent quantities, provided three assumptions are made: (1)All water delivered to a field and not infiltrated or not collected as runoff for reuse is a loss, and the nature of that loss is not important; (2)the requirement at the time of irrigation is the water necessary to fill the root zone; and (3)a single lumped parameter is adequate to characterize the distribution. This result allows the performance of an infield distribution system to be determined with a minimum of effort. Furthermore, most of the commonly used efficiency terms can be calculated from the four measured quantities. If limits of acceptability for system performance are defined, then the four measured quantities can be used to make decisions for improved irrigation practices or to compare capabilities of different systems.