The limiting resource for irrigated agriculture in Southern Australia is water not land.
The largest resource of water in Australia is the Murray-Darling Basin covering about one seventh of mainland Australia.
There is a cap on diversion of waters from the streams in the basin.
Increasing efficiency in the use of water is now a focus.
In the state of South Australia an integrated approach has been taken to match crops, irrigation system design, and management to the most appropriate soil types.
In the past, many developers of irrigation enterprises, whether for perennial or annual crops, have not considered the important components effecting irrigation management.
Consequently, problems have arisen from: (1) irrigation valve units spanning different soil types; (2) water application rates exceeding infiltration rates at the soil surface; (3) drainage and waterlogging problems caused by over-irrigation; (4) guessing how much water to apply, how often, rather than using an objective scheduling device.
To overcome the above problems, irrigation planning consultants and developers are adopting a methodical approach to establishing and managing irrigation enterprises.
The essential ingredients are: describing the soils, designing an appropriate irrigation system to match the soil and crop combination, maintaining the irrigation system to industry standards, measuring the use of water by the crop to apply the right amount of water at the right time.