Is suburban sprawl a threat to farming?

One of the oldest processes in urban development is the conversion of peripheral land from farming to residential use. The standard argument is highest and best use: housing gives a bigger pay-off than farming. It’s the same basic logic underlying why natural bushland is cleared for agricultural use.

On Monday I looked at the idea of “food kilometres” but today I want to look at whether productive agricultural land should be converted to urban use.

Straight up, the evidence suggests urban development doesn’t pose much threat at all. The productivity of agriculture in Australia has increased 2.8% p.a. over the last 20 years, double the rate at which the wider market economy has grown.

Moreover, the Australian Natural Resources Atlas shows that the area of land used nationally for urban development amounts to just 0.5% of the area of land used for agriculture. Another estimate by the Australian Collaborative Land Use Mapping Program puts the ratio of urban land to agricultural land at 2.8%.

A more detailed study by Peter Houston published in 2005 found that agricultural land on Melbourne’s urban periphery comprised a little less than 6% of the total land base used for agriculture in Victoria. Melbourne seems to be an exception – the average figure for peri-urban areas across all mainland States is a mere 1%. Read the rest of this entry »