Very interesting story. Here's a page that explains what the guy does in more detail: http://www.naturalsequencefarming.com/nsfpeter.htm
From what I understand, Australia once had many inland saltwater lakes and over time (1000 years or so) the salt water made its way underground into an aquifer type system. The natural habitat of Australia worked with the salt water underground, with certain types of plans absorbing the salt via deep roots which enabled the plants with shallow roots which could not deal with the salty water to survive.
European farming methods, clearing the land of its natural plants, over the past 200 years caused the salt water to literally destroy the landscape and the topsoil.
Peter Andrews figured out a way to get everything in balance again. The part in the video where they are looking at trees that grow in the sand and grew tall in a short amount of time... those are trees that help absorb the salt via their deep roots, keeping the salt away from the more sensitive plants.
Anyhow, the videos didn't explain much of that and my curiosity got the best of me. Seems like the guy is doing a good thing for their country..