Desalination techniques — A review of the opportunities for desalinationStewart Burn a,b,c,⁎, Manh Hoang a,b, Domingo Zarzo e, Frank Olewniak f, Elena Campos e,

The adoption of desalination for agricultural purposes in countries such as Australia has been very limited, with only a small number of cases available to demonstrate its suitability. This can be compared to countries such as Spain where the uptake has been significant. A number of suitable technologies such as reverse osmosis and electrodialysis are available to provide desalinated water, but not at a cost comparable to that for water commonly utilised for agricultural purposes. The use of blended waters, where the quality of the water is tailored to the crop may go part way to addressing this cost differential. However, if the overall efficiency of the combined production of water and food, as well as opportunities for better soil management is considered, then desalination's applicability to agriculture becomes more viable. The use of state of the art technologies for the provision of desalinated water for agriculture is most likely to be cost effective in a tightly controlled environment, using agricultural practices with the most-effective water use and crops with high productivity. Such conditions are often associated with greenhouses and the production of high-value irrigated crops, where the cost of water is small compared to the infrastructure investment. Crown Copyright © 2015 Published by Elsevier B.V. All rights reserved.

Suitable technologies such as reverse osmosis and electrodialysis to provide desalinated water for agriculture are currently available and can provide water for agriculture, but at a cost that is currently more expensive than that generally used for agricultural purposes. The adaptation of desalination to supply water for agriculture may be cost effective; especially when applied to high value crops where the cost of the water is not a critical issue. For these applications established technologies such as reverse osmosis and electrodialysis are being commonly applied in a number of countries around the world. Wider application of technologies, especially for broader scale allocations will only occur where there is limited availability of fit for purpose water for irrigation and will depend on further developments in desalination technologies, reduction in costs, and advancements in agricultural water-use practices that reduce water losses and increase water-use efficiency. In this context, the cost of water is always relative and depends on the availability of supply and its further use. In addition we must bear in mind that food supply and water security are issues of national importance and having an inexhaustible water resource, such as that which can be supplied by desalination, could be a factor that may make the cost of water insignificant.