The research made full use of new technology in the fields of soil water measurement and micrometeorology, enabling us to make a rigorous comparison of annual and perennial pastures in terms of their patterns of soil water use.

In Australia, dryland salinity is becoming a serious environmental problem. It is due to removal of native deep-rooted vegetation, and its replacement with shallow-rooted annual crops and pastures. The perennial pasture plant, lucerne (alfalfa), had shown promise in restoring the water balance in other parts of the world, and we wanted to see whether it could be effective in an environment not ideally suited to lucerne growth.

In Australia, dryland salinity is estimated to affect 6 million hectares currently, and this is forecast to increase to about 16 million hectares in the next 50 years unless some of our land use practices change. In this research, we demonstrated that lucerne, or other perennial plants, have the potential to restrict the expansion of dryland salinity, provided that they are incorporated rapidly and completely into current farming systems.