Hi Sue,
You might consider going to a Land-based college and getting some agricultural qualifications, if you've not done so already. You could go full-time on something like the Level 3 Extended Diploma in Agriculture or you might prefer an Apprenticeship. If you struggle to find an employer who will take you on as an Apprentice you may be able to get a placement via the little known Access to Apprenticeship programme if you are under the age of 25: http://www.apprenticeships.org.uk/Partners/Policy/AccesstoApprenticeships.aspx
It would be a good idea to go to your local land-based college's open day (on your return from Oz) and talk to the staff about your options. Or come to ours at Riseholme College, Lincoln:
http://www.lincoln.ac.uk/riseholmecollege/Non%20Course%20Pages/open_days.htm
Another possibility would be to join a Fresh Start Academy: http://www.careerinfarming.co.uk/
Best of luck,
Bill, Riseholme College