Topic 19: Case Study B – Southern Western Australia
The southern aspect of Western Australia was largely cleared of perennial native vegetation, mostly forests, from early in the 1900s until 1980. At that time a generalised ban on clearing was implemented, after which any removal of native vegetation was strictly controlled under permit.
The changes in soil characteristics and soil hydrology associated with this change in vegetation have progressed to the extent that many of the farming systems and practices in common use are now considered unsustainable. The ability of land to permit plant growth has been severely compromised over wide areas of the state, and the profitability of agriculture considerably reduced. Not only farmland is affected, but also native vegetation and urban areas.
Many of the specific causes of problems are now well understood; much of past practice was perpetuated in ignorance. The current state of knowledge and awareness is such, however, that remediation is possible, and certainly continued farming will depend upon changes in many areas.
In this topic a case study for a farm in the ‘South Central’ zone is presented.
At the end you should understand:
- The reasons for land degradation in the south-west of WA;
- The major problems confronting farming businesses;
- Indicators to measure and monitor soil, pasture and farm attributes; and
- Remedial techniques offering a best bet at this stage to be put into practice.