Jared Diamond argues that Australia has poor soil fertility due to the lack of recent volcanic or glacial activity. The areas that did have glaciers over-turning the land were the area south of Fremantle and the Adelaide area. By Australian standards these are very fertile - by world standards they are average.

Diamond mentions that Adelaide was the first self-supporting colony using European agricultural methods due to the fertility of its soil. He consequently asks;

... would Australia be better off economically without much of its present agricultural enterprise?

The background to this rethinking is the realisation that only tiny areas of Australian land currently being used for agriculture are productive and suitable for sustained agricultural operations.

While 60% of Australia's land area and 80% of its human water use are dedicated to agriculture., the value of agriculture relative to other sectors of the Australian economy has been shrinking to the point where it now contributes less than 3% of the gross national product.

That's a huge allocation of land and scarce water to an enterprise of such low value. Furthermore, it is astonishing to realise that over 99% of that agricultural land makes little or no positive contribution to Australia's economy.

It turns out that about 80% of Australia's agricultural profits are derived from less than 0.8% of its agricultural land, virtually all of it in the south-western corner, on the south coast around Adelaide, in the south-eastern corner and in eastern Queensland

Those are the few areas favoured by volcanic or recently uplifted soils, reliable winter rains, or both.

I was not aware of the inherent disadvantage in Australian soils. I just assumed soils were soils all over the world. The soils were rich once, but basically over millennia have been leached into the oceans. Ironically, the poor soils mean few nutrients reach the ocean, so much of the fisheries in Australia are poor by world standards as well.

For a long time Australia was not a self-supporting colony. It was dependent upon trade from Britain to sustain itself. We are a trading nation today, maybe we should eradicate subsidies for agriculture and leave ourselves at the mercy of the free market. At worst it will probably mean we pay less for food.

Australians are aware of environmental damage, water is probably the one that we are most cognisant of. It is obvious to most Australians that having a water intensive agricultural industry like rice in the Murray region is repugnant. Maybe awareness of the poor quality of our soils needs to permeate the public conscious in the same way managing a scarce resource like water has .

More Reading on Jared diamond

• Jared Diamond
• Environment
• Jared Diamond asks in Collapse
• The Limits of Soil
• Why No Aboriginal Agrarianism?