Hi Boltz,
How I got a start in the industry is a bit dated now. Australian agriculture and for that matter aerial ag has seen a lot of changes in the last 23 years, so advice from someone that has entered the industry in the last 3 to 5 years might be better help. As for flying experience before doing my ag rating, I had about 150 hrs tailwheel glider towing, about 30hrs meat bombing and 200 hrs VFR charter. Hope this helps.
PS: I came from a farming background and this helped a lot.