Policy Forum #3

Research & Development Priorities for Salinity in Western Australia

Sally Marsh, CLIMA, University of Western Australia
Don McFarlane, Agriculture Western Australia

In 1998, the Western Australian Salinity Council initiated a review of R&D salinity, which involved broad consultation. This review has established the R&D priorities for salinity in Western Australia.

This R&D review ensures that the Salinity Action Plan is closely aligned with the National Dryland Salinity Program Phase 2 (NDSP) and other R&D initiatives. The NDSP is funded mainly from the Land and Water Resources Research and Development Corporation, the Grains Research and Development Corporation and the Murray Darling Basin Commission.

All R&D areas identified for salinity in Western Australia were given a high priority through the review process. These priorities are listed in decreasing order of importance below.

1. Increasing the range and potential of perennial plant species

Perennial deep-rooted plants have greater water use potential than the annual shallow-rooted plants that predominate in Western Australian agriculture. Further R&D is required to identify suitable woody perennials and perennial grasses and herbs, and ensure their effective integration into Western Australian farming systems.

Perennial pasture species or cultivars have not been identified for the full range of climate, soil and rotational settings relevant to the agricultural areas of the State.

There is a need to define the geographic boundaries of currently available options and establish whether these can be made more widely applicable. There is further need to identify new perennial plants capable of filling ecological or management gaps, particularly those with potential for rapid and wide scale adoption by producers.

Key R&D priorities for perennial grasses and herbs include:

• identification of suitable genotypes and associated management system for all rainfall regions, soils and farming systems, with an urgent priority for systems suited to phase cropping systems on light-textured soils in the 400-600 mm rainfall region;
• maximisation of the role of lucerne in WA farming systems; and
• management systems for perennial grasses and herbs that maximise their effective water use.

The range of economically viable tree and shrub options is too limited. Furthermore, landholders require better information on targeting tree species to locations where they will achieve economic production; and the capacity of trees to lower water tables. Key R&D priorities for woody perennials and trees include:

• the selection and commercialisation of tree species suitable for the medium and low rainfall areas;
• the integration of trees and shrubs into farming systems; and
• improved understanding of the effects of site conditions and salt accumulation in the root zone on plant survival, growth and water use.

2. Better understanding of biophysical processes

The contribution of preferential flow to groundwater recharge requires clarification. There is further need to clarify the impact of soil structure, modified by changed land use, on preferential flow pathways, and possible improvements by perennials. Key R&D priorities include:

• recharge assessment procedures; and
• quantifying the soil physical properties which affect the flow of water in shallow or unsaturated soils.

To understand and quantify groundwater discharge it is necessary to define groundwater flow systems. This will enable the effects of changed land use to be more accurately predicted. Key R&D priorities at a catchment scale include:

• further developing methods to determine where groundwater discharge or shallow water tables will occur in the landscape in response to land and water management practices;
• quantifying aquifer properties; and
• investigating the importance of fractured rock systems in salinisation.

3. Appropriate institutional arrangements and policy design

Social, economic and institutional factors play key roles in decisions about management options. R&D funding to investigate the potential effectiveness of different policies for salinity management in Western Australia has been very small relative to investment in the physical and biological sciences. Key R&D priorities are:

• design and evaluation of alternative policies and institutional arrangements (such as subsidies/incentives, taxes, property rights, duty of care, rating);
• fairness/equity aspects of institutional arrangements and policies; and
• social consequences of the salinisation of land and water, and other social research.

4. Assess and monitor the impact of salinity

Shallow water tables and saline soils are resulting in the obvious loss of productive agricultural land. However, the full extent of the less obvious impact of salinity on infrastructure, water resources and ecological processes is not yet established Key R&D priorities include:

• the extent of salt-affected land, and the cost of salinity to the community;
• salinity impacts on infrastructure, water resources and ecological processes;
• monitoring systems for groundwater; and
• increased biological survey and monitoring effort.

5. Rehabilitation and productive use of saline land

Development of productive saltland pasture systems based on combinations of perennial and annual species in the low and medium rainfall areas is a high priority. Key R&D priorities include:

• options for annual and perennial systems;
• relative water use by perennial and annual components;
• determining soils and climates for which these pastures are appropriate; and
• management systems that maximise water use, animal productivity and economic gain.

6. Biophysical and socio-economic modelling and decision support tools for managers of public and/or private assets

The development of land planning tools will require concurrent work in biophysical, economic and social modeling. In particular hydrological impacts of salinisation will extend over entire river systems. Modelling of this is required to assess changes in flood regime, salt loads, externalised benefits and costs, and impacts on river and vegetation health.

In addition, landholders are reluctant to implement salinity management systems because of uncertainty about their effectiveness or economic returns. Decision support tools, and further R&D, are required at three levels:

• simple modeling tools which allow ‘what-if’ modeling of options using local data;
• tools that integrate farm management systems (biophysical systems, treatments, and economics) and deliver ‘best-bet’ options for salinity and water management at the farm or landscape scale; and
• models that integrate the above with social objectives of the community about the environment and other interests.

7. Extension method evaluation and continuous improvement

The complexity and risk associated with making fundamental changes to farming systems in focus catchments requires that extension methods be continuously evaluated and improved.

Agencies and landholders are investing time and effort in focus and recovery catchments and need to assess the efficiency and effectiveness of this approach. Research and development is therefore is needed to ensure extension methods remain effective. There is also a need to examine the "community capacity" to partake in group activities.

8. Engineering methods of addressing excess water and salinity problems

Engineering may be required to protect rural infrastructure and threatened natural resources. Drainage is one such technique used extensively by farmers. However, the effectiveness of drainage in ameliorating salinity requires clarification. Key R&D priorities include:

• hydrologic studies and impact statements for large engineering structures for flood mitigation and salinity management;
• assessment of off-site pollution and inundation risk based on various levels of increased drainage;
• monitoring major existing or new sub-surface drainage systems; and
• hydrologic analysis of drains at a paddock scale.

9. Protection of natural resources from the threat of salinity

Improved knowledge of the natural resources - including land, water and biodiversity - as well as threats to sustaining their values is required. Improving methods to manage remnants to maximise their water use and biodiversity values in an altered landscape is also required.

10. Increasing water use by annuals

Annual crops and pastures occupy the largest area of the landscape in our agricultural systems by far. There is scope to manage annuals to increase water use. Research is required to further understand water use, water use efficiency and basic hydrologic outcomes of annuals Summer-growing fodder and grain crops have potential to increase water use. Research is also needed to determine areas suited to summer crops and their impact on the landscape water balance.

11. Aquaculture in inland saline water

Aquaculture has the potential to generate income from saline water. Research is needed to provide information on production yields and costs, and market prices for aquaculture species produced using static, naturally flowing or pumped saline water. Guidelines for the environmentally sustainable production of aquaculture species under these conditions need to be developed.

ACTION

The State Salinity Council, through its Salinity Research & Development Steering Committee, will coordinate and facilitate submissions for external funding opportunities in salinity for Western Australia.

Agriculture WA, in conjunction with the other agencies, will support the Steering Committee, and co-ordinate and support a Salinity R&D Technical Committee and a broader network to advise the Committee.

Agencies, production groups, academic institutions and community groups will pursue R&D funds to address salinity issues.

(Funding from existing programs and new R&D grant opportunities)

SEA News Issue #3

The SEA News index is at http://welcome.to/seanews

Copyright © Sally Marsh and Don McFarlane, 1999
Last revised: May 21, 2003.