Salinity research in Australia over the past decade has generated a wealth of new knowledge that has yet to be incorporated in policies and investment strategies. The SIF3 project will work with governments (national and state) and with regional bodies responsible for salinity investment planning to bridge the gap between state-of-the-art knowledge and action.

Our aim is to integrate a full range of hydrological, biological, economic and social research to understand of how best to respond to dryland salinity in different circumstances.

We are concerned with impacts from dryland salinity on: (i) agriculture through land salinisation, (ii) water resources, (iii) infrastructure, and (iv) vegetation and biodiversity.

We identify circumstances where it would be logical for particular policies to promote uptake of existing management options. Policy makers have a number of choices on the policy ‘menu’ including:

• Extension: Technology transfer, education. Relevant where existing management options are attractive to land managers.
• Incentives: Positive financial incentives to encourage a change of management. Examples: subsidies, market-based instruments, cost-sharing. Relevant to promote existing management options to protect public assets where off-site benefits exceed on-site costs.
• Penalties: Negative incentives to discourage a practice or land use. Examples: transferable water rights, regulation on land use or drainage, zoning, government acquisition. Relevant to discouragement of existing plant-based systems in some circumstances, esp. water resource catchments where salinity management can cause downstream costs.
• Engineering: Salt interception through pumping saline water to avoid discharge into rivers. Local engineering works on-site to protect public assets where problem is generated locally (e.g. many towns). This category represents direct investment in public engineering works. Engineering for agricultural land is captured in other categories (e.g. extension, penalties).
• Plant-based R&D: Invest in development or improvement of technological options for salinity management, particularly plant-based R&D systems. May also include investment in infrastructure, market institutions, etc. to support profitable new industries.
• Other R&D: e.g. Research to provide information to support planning and decision making. Research into the performance and design of engineering options.
• No action: No response is justified where the costs of intervention outweigh the benefits.

Several of these categories would be relevant to the broad category of ‘capacity building’: extension, incentives, R&D, some types of engineering works, and perhaps incentives.

Recommendations

We identified 60 distinct situations where specific strategies could be recommended, depending on the type of asset affected, hydrological conditions, and the economics of available responses. Recommendations are very sensitive to these conditions, and are based on a mixture of research results, theory, judgments and logic. Ridley and Pannell (2005) provide the complete set of recommendations. Here we provide a very brief summary for each type of asset.

The process of identifying the appropriate response to salinity is illustrated in the figure below. It shows how the choice depends on the type of asset and on several other factors. The set of influential factors is different for each asset type. For waterways, the important factors are salt input, groundwater response, fresh runoff and the economics of perennials.

Summary of recommendations for all asset types

Where the main aim of salinity management is to reduce impacts on water resources, the logical approach in some upper catchment areas is for penalties or permits to prevent loss of fresh water runoff entering waterways. There are few cases where providing incentives to grow existing plant-based options is the most appropriate response. Investment into plant-based R&D is justified in several cases, particularly where groundwater systems are responsive and the potential for runoff generation is low. In a minority of locations, salt interception schemes are technically and economically feasible.

For protection of high value, non-agricultural terrestrial assets (infrastructure and biodiversity), each of the policy approaches is relevant in some circumstances, although the role for incentives is very limited. Engineering (subject to economic analysis) may be appropriate when the value of the asset is high and the urgency for action is high. Plant-based R&D is relevant in a number of situations, particularly where the asset value is high but the urgency is low. It is justified on the basis of reducing the public cost per hectare of treatment.

Compared with infrastructure and biodiversity, agricultural land is generally of low relative value per hectare. Where profitable perennial options exist, extension is the main tool. More commonly, where current plant-based options are not sufficiently profitable, R&D to develop improved options should be undertaken as the main publicly funded response.

Where land is already salt-affected, development of plant-based or engineering options is justified where the downstream impacts are positive or neutral and where profitable options are lacking. A choice between penalties and no action applies where the downstream impact of managing salt-land is sufficiently negative.

Conclusion

The study has a number of implications for government, R&D corporations, and catchment managers. It provides a pathway to more cost-effective and scientifically defensible investments in management of dryland salinity by providing guidance on the broad categories of policy measures that are appropriate in different circumstances. It highlights the need for salinity investments to be highly sensitive to case-specific circumstances, and well informed by science. It implies that there should be a number of shifts in emphasis in the funding directions of the existing policy program, most notably less emphasis on incentives and extension. It confirms the appropriateness of the attention that has recently been given to engineering and permit-based approaches. Given that two of the more prominent policy responses in our recommendations are plant-based R&D and penalties, and that these are likely to be best considered, managed and implemented at scales greater than existing regional bodies, the degree of emphasis on regional decision making in the existing program should also be reconsidered.

Appendix: Responses for recharge areas with salinity impacts on waterways

This appendix provides a slightly more detailed discussion of the results for water resources, in order to provide a feel for the nature of the results. There are four main factors driving the choice of policy approach to protect water resources:

(i) The potential input of salt from groundwaters into the waterway. Depends on recharge rates (dependent on soil texture and slope), salt stores in soil and salt concentration in groundwaters, all of which can be highly variable, even within a sub-catchment.

(ii) The responsiveness of groundwaters in potential discharge areas to establishment of new perennial vegetation in recharge areas.

(iii) The importance of fresh runoff water. Includes both the level of use of the waterway for consumptive use and the volume of surface or near-surface flows of fresh water entering the waterway (dependent on soil texture, slope, vegetation type and rainfall).

(iv) Farm-level economics: whether current perennial-plant options for reducing recharge on farm-land in the sub-catchment are more or less profitable than annual-based agriculture.

Table 1 shows a selection from the 24 situations analysed for water-resource catchments. Choosing responses is straightforward once one has identified the relevant criteria.

^AWhether penalties or extension applies requires analysis of net off-site effect of perennials.

^BIncentives paid to establish/manage existing perennials if the net effect is positive.

For example, extension is recommended in cases 1 (subject to further assessment), 4 and 16, because in these cases the management options are attractive enough to promote uptake by business-oriented land managers. Penalties are recommended in cases 1, 2 and 15, because in these cases there is a likelihood of adverse downstream impacts in excess of upstream benefits. In the fuller table (Ridley and Pannell 2005), penalties or permits are the most common recommended policy response for protection of water resources.

Plant-based R&D is recommended in cases 5 and 12, as perennial vegetation would be beneficial, but not so beneficial as to warrant support with subsidies. Engineering-based salt interception schemes (where economic) are suggested where the salinity threat is high but groundwater responsiveness to revegetation is low (case 12).

Incentives to grow existing plant-based options are only an appropriate response in cases 2 and 5 (high groundwater response, perennials slightly less profitable than annuals). In case 5, site-specific analysis would be needed to assess whether incentives, development of plant-based options or a mixture provides the greatest net benefit.

David Pannell, The University of Western Australia

Further Reading

This is a very brief summary of the following paper:

Ridley AM and Pannell DJ (2005). SIF3: An investment framework for managing dryland salinity in Australia. SEA Working paper 1901. CRC for Plant-based Management of Dryland Salinity, University of Western Australia, Perth. Available at SIF3 project page