Other countries like the US subsidize and guarantee the food produced will be purchased if not sold, with tax payers money. The day Australia fully opens the floodgates to foreign food imports will mark the day Australia truly starts becoming a s*h*i*t*hole.
The right argues for the free market and says that if Australian farmers cannot compete they should find another job. This is the most dangerous mind*f*u*c*k, the right has ever tried. The fact of the matter is that the free market doesn't exist with subsidies/ government guarantees and differences in currencies.
The loss of food production in Australia is tantamount to Australia having no military. Without a doubt food is the most important commodity. When Australia has no food production of its own, it will give the countries/corporations that we import from nearly unlimited power over Australia. This is especially dangerous in today's climate of possible imminent global collapse. If there is global economic crash/ anarchy, food becomes the most important thing there is. Australia becomes truly ****ed at this stage when it has to rely on food imports.
Not to mention the dim future of food production, without significant scientific breakthroughs, food will become a major problem in the future.
1) With overpopulation, more people need more food.
2) Loss of arable farmland due to the effects of over farming e.t.c.
3) Peak oil and the peak of other resources, our current form of agriculture relies heavily on oil, ammonia the precursor to food/fertilizer is produced with natural gas. Phosphorus and Potassium are also extremely important in our current form of agriculture, needless to say they are also mined and as we use up the easily extractable/mined sources for these chemicals a problem will appear. There is a reason BHP tried to do a hostile takeover on Canadian Potash Corporation. Potash = Potassium. RIO also has some Potash resources.
4) With the loss of cheap energy/oil food will increasingly become more expensive to produce and transport.