Using the 2004 ANCID/Sustainable Irrigation Travel Fellowship, David Allen conducted an international survey of over 100 geophysical instruments applicable to irrigation problems.

Geophysical techniques involve the use of ground-based and airborne geophysical devices to measure physical properties of the earth.

During their visit, the US Scientists interacted and shared experiences and

techniques with Dr David Nehl and Dr Om Jhorar of NSW Agriculture, Dr Stephen