People - Structural Change in Australian Agriculture: Implications for Natural Resource Management
Part 2: Salinity Case Studies Balance Modelling — Australia
By Neil Barr, Department of Natural Resources and Environment, Victoria
June 2001
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About the report
This report discusses four regional case studies and examines the capacity of the local and the wider community to change in a manner that might achieve improved salinity control. The study utilises the outcomes of biophysical, economic and social modeling undertaken within other projects of Theme 6 of the National Land and Water Resources Audit to explore this theme.
In the Wanilla catchment of the Eyre Peninsula in South Australia, it is concluded that the only practical option available to the local community is to learn to live with salinity. Whilst this might contain some pain, it is less painful than the alternative of recharge control.
In the Kamarooka region of Victoria there is little likelihood of an expansion of the existing extent of salinity. The existing salinity damage is recoverable over a century with the replacement of annual pastures with lucerne pastures. The local farm community has already undertaken extensive planting of dryland lucerne. However, further planting will be mediated by the relative returns of cropping and grazing enterprises. At present, and for the foreseeable future, it is likely that cropping will remain more attractive. In the longer term, there is reason to question the extent to which farming will remain a dominant land use in this district.
In the Lake Warden catchment of Western Australia there is a rapidly expanding shallow water table. The local farm community has the capacity to increase the area of dryland lucerne to reduce the recharge of water tables. Anecdotal evidence is that this is well underway. However, whilst this will reduce recharge, in the long run it will delay but not reduce the ultimate impacts of dryland salinity on farm land. Delaying the ultimate expression of salinity will reduce the social and economic impact of salinity by providing a far longer time for structural adjustment. Even in the short to medium term it is unlikely changes to existing farming systems will save the downstream wetlands of Lake Warden. A landscape change option to save these wetlands based upon extensive reforestation would impose social and economic costs on the local community far greater than the costs of unmitigated salinity.
Upper Billabong Creek is perhaps the most instructive case study. An investment in improved understanding of catchment processes has revealed a far lesser salinity problem than initially expected on the basis of limited monitoring and best bet understandings of salinity process. This underlines the importance of reliable science based understandings of regional salinity as a foundation for public investment decisions.
The key lessons derived from the case studies are:
- There is no simple broadly applicable paradigm with which to conceive our responses to salinity.
- Expectations of farm based change leading to salinity control need to be tempered.
- Broad scale reforestation proposals will often be poor investments from an economic and social perspective.
- A lack of profitable technically feasible options is the major constraint to the capacity to control salinity.
- The major issue of "capacity for change" is the capacity of our community to make informed decisions about investment in salinity control.
- We need to re-engineer our integrated catchment management structures to operate within an adaptive management framework.
- Investment in salinity control should be based upon a triage model.
- A "works on the ground now" imperative should be tempered by a "least regrets" investment approach.
- Landscape change must be seen as a multi-generational challenge.
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