Project Title

Evaluation of the impact of climate change on northern Australian grazing industries

Objective

• To evaluate the impact of climate change and CO₂ increase on the management of northern Australian grazing industries.

Climate change, increase in atmospheric carbon dioxide, and policies on greenhouse gas emissions are important issues for the northern Australian grazing industries. The majority of sheep and beef cattle graze the large extent of native pastures in this region. The number of animals stocked, individual animal production, and the risks of land and pasture degradation are strongly affected by climatic variability.

As well as emissions from grazing animals, land use management options such as tree clearing and pasture burning are important components of the national greenhouse gas inventory. Thus, the grazing industries are in a difficult position with their production and sustainability being sensitive to climate change and the industries also being seen to be a major contributor to national greenhouse gas emissions. This project sought to kick start climate change impact studies and to commence analysis on the impact of grazing and climate on soil organic carbon.

Research

To address these issues, the project examined current trends in the climate of Queensland grazing lands; developed models of animal production from native pastures in cooperation with other RIRDC and LWRRDC projects, and two PhD theses; evaluated different approaches to simulate climate change scenarios; modified a native tropical pasture model GRASP to include the effects of increasing atmospheric carbon dioxide concentration; and developed comprehensive maps of soil organic carbon, soil phosphorus, soil nitrogen and other resource attributes.

Outcome

Most of the project's limited objectives were met in combination with other RIRDC and LWRRDC projects. However, several aspects proved too difficult to complete given a rapidly changing work environment. Resources have now been allocated in the new Queensland Centre for Climate Applications (QCCA) to improve the models developed in this project and to simulate the possible economic impact of climate change scenarios.

The simulation models will require further development to more correctly represent the effects of different climate variables (such as temperature, vapour pressure deficit) and the interaction of C0₂ concentration and biological responses (for example, water stress on growth, nutrient concentration). The major outcome of the project will be an evaluation of the impact of climate change and possible adaptive strategies for each grazing industry. The evaluation will be the first analysis of its type and is designed to convert industry from a reactive to a pro-active approach to climate change.

Implications

Although climate change has been firmly established as a core business research activity, the lack of clear view of likely climate change for northern Australia limits current extension or policy formulation. The major policy issues for the grazing industries (tree clearing, woodland thickening, possible negative impacts of global warming) can not be separated from other major issues such as property viability.

RIRDC Project No: DAQ-139A

Researcher: Dr G M McKeon

Organisation: QCCA, 80 Meiers Road, INDOOROOPILLY QLF 4068

Contacts: Phone: (07) 3896 9548    Fax: (07) 3896 9606

Innovative approaches to poly tunnel technology

Objective

• To establish the economic and technical feasibility of utilising saline ground water for the production of Beta-Carotene, for aquaculture, production of potable water and production of commercial salt.

Inland aquaculture has the potential to be one of the biggest growth industries in Australia. Saline water is relatively cheap to obtain and at the same time its removal addresses a significant land degradation problem. Furthermore, inland aquaculture is not be affected by the problems such as toxic algae and tidal fluctuations.

The cost of setting up an inland aquaculture industry could be cheaper than a sea based aquaculture. Access is easier during all types of weather and supplying fin fish all year round to markets.

Research

Saline ground water was pumped into PVC covered horticultural tunnels containing shallow pool liners. Evaporation was high. On a 25°C day, temperatures in a PVC tunnel reached 40-50°C.

The stored saline water was found to be suitable to grow fin fish, brine shrimp, Beta-Carotene (a food additive) as well as for extracting salt and bitterns.

The project was run by the Coorong District Council, SA and also supported by the South Australian Research and Development Institute.

Outcome

Fish, beta carotene and other saleable commodities were produced. The process was comparatively cheap to set up. It uses solar energy which allows for extended months of operation. During winter, the tunnel structures can be used to propagate plants and for other experiments.

Implications

A pilot groundwater salinity project in South Australia has revealed an innovative and profitable approach to addressing Australia’s rising saline groundwater problems by using what is an emerging problem and turning it into a resource.

RIRDC Project No: MDC-1A

Researcher: C E Fisher

Organisation: Coorong District Council, PO Box 28,  MENINGIE SA 5264

Contact: Phone: (08) 8572 3611   Fax: (08) 8572 3822

Modelling water and energy requirements for sustainable rangeland management

Objective

• To measure energy and water turnovers of exercising sheep and thus define minimal pasture density and water availability below which land degradation is certain to occur.
• To apply the results for sheep for rangeland conditions to improve the predictive reliability of the management program 'RANGEPAK Paddock'

Land degradation on grazed semi-arid rangeland is greatly influenced by the climate, the density and quality of pasture, and the placement of water sources. Analysing biological and physical exchanges of heat and water between livestock and their environment in semi-arid regions should assist development of mathematical models for planning livestock and land management.

A series of laboratory and field experiments were undertaken to provide direct measurements of the effects of these factors on livestock so as to allow comparison with mathematical models being developed by other workers to monitor the sustainability of such agricultural systems. The data were used to verify the CSIRO grazing model 'RANGEPACK Paddock' and the mathematical model of energy balance being developed at the University of Nottingham.

Research

Firstly, water and thermal balances were measured on sheep in laboratory conditions. Oxygen use and water losses via skin, respiration, urine and faeces were recorded at air temperatures of 20 - 38C on exercising and resting sheep with fleece lengths of 10-85 mm. Secondly, water turnovers and feeding behaviours were recorded outdoors in commercial sheep flocks grazing high protein lupin or lower protein wheat stubbles.

Laboratory data permitted calculation of thermal and water balances of grazing animals, after allowances were made for the effects of solar heating. Indoor values could be reconciled with field grazing observations, although in paddocks of stubble, grazing patterns were different to those expected on rangeland.

Outcomes

The modelling of field performance of sheep in semi-arid environments appears to be feasible, though at present not with precision to determine grazing range accurately.

The concordance between field and computer-generated data suggest that most fundamental processes have been accounted for. Several possible sources of disparity have been identified. Including them in future computer models should improve predictability, but would complicate the procedure to some extent.

Implications

The researchers believe that data produced in this series of laboratory and field trials will provide a resource base of thermal and water balance information on which further development of computer models could be based.

RIRDC Project No: UMU-14A

Researcher: Dr Ken Johnson

Organisation: Murdoch University, South Street, MURDOCH WA 6150

Contacts: Phone: (08) 9360 2257   Fax: (08) 9310 4144

Development of generic DNA-based technologies for identification of Phytophthora pathogens of a wide range of plant species

Objectives

• The objective of this project was to design a diagnostic test for a number of species of the fungus Phytophthora which are economic important pathogens in Australia. The latest developments in biotechnology and molecular genetics have been used to develop quick and reliable tests which are highly specific and very sensitive and amenable for routine screening of plant material and soil for the presence of Phytophthora pathogens.

Phytophthora incited diseases cause severe devastation to a great variety of tree, ornamental and crop plant species. Although the severity of disease can vary greatly from year to year, depending on differences in climatic conditions (e.g. temperature, waterlogging) and cultivation practices, good diagnostic procedures are essential to identify potential problems prior to widespread outbreaks of disease and for quarantine purposes. Management options to control Phytophthora are rather limited in many situations. Resistance or tolerance is often used in field crops but this is not always a valid option in forestry, nursery, or fruit crops. The use of chemicals is limited to drenching the soil with metalaxyl or injection of phosphonates which has proven to be successful in some cases such as avocado root rot. Phosphonates and metalaxyl do not have a curative effect. Therefore, as soon as application of these compounds stops the Phytophthora root rot comes back very quickly. In the nursery industry, which is increasingly moving towards container grown plants, disease free planting material and disease free soil is the sole means to produce healthy plants.

Research

Recent advances made in the CRC for Tropical Plant Pathology, in the understanding of the genus Phytophthora (especially P. cinnamomi) at the molecular level have led to the development of PCR-based diagnostic tests with a high level of specificity and sensitivity, allowing specific detection at very low inoculum levels. These tests show enormous potential for use in commercial diagnostic laboratories. However, the tests are currently only applicable in research laboratory situations, and require rigorous testing and further development before commercial use is feasible. More research is also required on other species of Phytophthora of importance to the nursery and horticultural industries (target species include P . cryptogea, P. drechsleri, P. parasitica, P. nicotianae, P. palmivora, and P. cactorum) so that routine PCR protocols can be developed for these economically important Phytophthora species.

Outcomes

The final outcome of this project is a PCR based diagnostic test specific for the targeted Phytophthora species and the genus Phytophthora. Specific outcomes are:

• Insight in genetic diversity within important species of Phytophthora in Australia.
• DNA sequence information of variable and conserved parts of genes encoding ribosomal RNA (rDNA) in Phytophthora species showed little diversity within species and considerable diversity between species, allowing the design of both highly specific species and genus specific primers.
• Design and testing of DNA based diagnostic tests for the following targeted Phytophthora species; P. cinnamomi, P. cryptogea, P. drechsleri, P. parasitica, P. nicotianae, P. palmivora, and P. cactorum.

Genus and species specific diagnostic test that can detect as little as 2 pg of Phytophthora DNA in a given sample.

Implications

The availability of rapid diagnostic tests for Phytophthora will change the way in which diagnostics are used in the nursery and horticultural industries. The availability of cheap test which can be routinely applied will lead to improvements of nursery hygiene, the routine testing of planting material and soil and forms an integral part of accreditation schemes. The tests do not prevent disease but they are important in detecting disease before they become troublesome.

Rapid and correct identification of Phytophthora species will help resolve problems in crops from which Phytophthora is hard to isolate and in root diseases on crops from which Phytophthora has not been reported before. New and exotic species of Phytophthora can be more easily and accurately identified than before.

When routine diagnostics is put into place more samples can be routinely screened. This will lead to better disease management strategies and diseased plants can be identified more quickly before spread of Phytophthora can take place.

Rapid identification and detection of species is of extreme importance in import and export of plant material. The availability of such test will put Australia at the forefront of diagnostic capabilities in the world.

Publications

A full patent has been filed (No. 16330797; DNA-based methods for detection of Phytophthora species) on 14-3-97 based on the outcomes of this project. RIRDC, GRDC, HRDC, and the CRCTPP share the equity. In order to protect the intellectual property of our findings no publications have been written concerning the outcomes of this research.

RIRDC Project No: UQ-39A

Researcher: Professor J.A.G. Irwin, Dr. D.J. Maclean, Dr. A. Drenth

Organisation: Cooperative Research Centre for Tropical Plant Pathology (CRCTPP), Level 5, John Hines Building, The University of Queensland,  ST. LUCIA, QLD 4072

Contacts: Phone: (07) 3365 2790      Fax: (07) 3365 4771

       Last updated: 17 August 1998 Copyright © RIRDC http://www.rirdc.gov.au/comp98/npp1.htm