The geographic history of agriculture in Australia - its dynamics in time and space - is an interesting story. The size of the agricultural industry grew first in response to the local demand for its products. From the mid nineteenth century, when key technological and scientific developments occurred, the growth of the agricultural industry was influenced by the size of export markets.

As might be expected, the initial clearing took place surrounding the first colonial settlements. With expansion, the areas with more suitable soils and climate were sought and occupied. It was at these early stages of colonial expansion that the forests were cleared. Some, localised pockets of rainforests along the east coast of Australia were first logged, then cleared entirely for cropping or for dairy production.

During the latter half of the last century and the beginning of this one, there was a significant increase in clearing for the cultivation for wheat. This expansion took place out from the wetter areas close to the coast onto the plains, resulting in the extensive clearing of the woodlands of these drier localities.

Some of the serious land degradation problems to be found in the extensive croplands had their origins at this early expansion stage. Even so, there are also quite serious land degradation problems to be found in the extensive croplands that have been created since that time, even during the last 20 years.

By the mid 1920s the core areas of extensive agriculture were occupied, and perhaps 50% of the landcover conversion undertaken. Since then, the expansion of agriculture has been at the frontier - at the margins of the established agricultural lands.

This frontier expansion was facilitated by advances in technological capacity and understanding as well as encouraged by economic conditions and political initiatives.

The political control of the clearing and development of land in Australia has overridden all else, including the (well known) hard reality of unsuitable soils and unreliable climates. I urge you to read some of the references suggested at the end of this Chapter. The authors systematically detail the land degradation problems that are now depressingly common in the agricultural areas, and analyse why they occured. Dreadful mistakes have been made. They must never be repeated.