World’s Soil Resources

Australia
In their review of replicated Australian field trials with time-series data, Sanderman and Baldock (2010)
concluded that, although the implementation of more conservative land-management practices will lead to
a relative gain in soil carbon, absolute soil carbon stocks may still be on a trajectory of slow decline. There are
also inevitable trade-offs between agricultural production (e.g. carbon exports in the form of crops, fibre and
livestock) and carbon sequestration (capture and storage) in soils.
SOE (2011) provides a district-by-district assessment of trends in soil carbon for Australia. The assessment
concluded the following.
• The time since clearing is a key factor determining current trends. For example, large parts of
Queensland are still on a declining trend because widespread clearing for agriculture was still occurring
in the 1990s.
• Few regions have increasing soil carbon stores.
• Regions with intensifying systems of land use (e.g. northern Tasmania) have decreasing stores.
• Most regions with a projected drying climate have declining trends.
• The savannah landscapes of northern Australia have significant potential for increasing soil carbon
stores, but this requires changes in grazing pressures and fire regimes.
• Some of the extensive cropping lands in southern Australia with weathered and naturally infertile soils
have not experienced as large a loss of soil carbon since clearing (e.g. generally a 30–70 percent loss and
sometimes