Trends in the use of surface irrigation in Australian irrigated agriculture: An investigation into the role surface irrigation will play in future Australian agriculture

Surface irrigation methods are simple, mostly gravity driven and, therefore, have low energy requirements. However, these systems are often seen as being inefficient both in labour and water usage. As competition for scarce water resources and greater emphasis on environmental conservation gain ground, more focus has been directed towards surface systems. On the one hand, some irrigators have converted to pressurised systems, which are seen to be more water efficient. This is reflected in the decline of 15% of the proportion of irrigated land in Australia under surface irrigation in the last two decades; however, the proportion of agricultural establishments using the system has remained relatively unchanged since 2002, except during the drought period when there was a reduction. In the US there has been a reduction in both the acreage under surface systems and the number of farmers using the system. On the other hand, surface irrigation has experienced improvements ranging from upgrades of physical irrigation infrastructure and hardware to advanced management practices, including computer simulation and real-time optimisation and control. Conversion of irrigated land from surface to pressurised systems might continue into the future but probably at a decreasing rate. However, surface systems will nonetheless remain important. There is also the strong possibility that rising energy costs will curtail the adoption of pressurised systems.