Working On Sustainability

The Lower Balonne is a healthy river.  Smartrivers intends to keep it that way.  The Government’s monitoring of the river to date has been haphazard, with the last Government funding monitoring taking place in 1997.  Concerned about their environment and the continued health of the river and the subsequent health of the communities that rely on the river, Smartrivers has spent approximately one million dollars of community raised funds to undertake the most extensive monitoring program to date of the Lower Balonne to date.  Irrigators are also employing new technology to reduce their water usage and protect their river.

One of the most challenging issues facing Australia is the sustainable management of the land and water resources that support our local economies and our distinctive environment.  Smartrivers strive to contribute to the economic development of Queensland in accordance with the doctrine of ecologically sustainable development.  We support the concept of sustainability whole-heartedly. 

The benefits gained from living by this mantra mean that our community can live day to day in a way that is acceptable and does not impact upon the natural environment to an unacceptable level. 

Smartrivers recognises the importance that must be placed on the sustainable management of our land and water resources in the Lower Balonne.  Despite the fact that we are still within the formative stage of large-scale irrigation within the Lower Balonne, we are investing heavily in monitoring and understanding what sustainability within our rivers and on our floodplains really means.  This is mostly dealt with in “Science For All”.

An equally important area of investigation is on farm sustainability.  This reflects the areas of on farm activity that will effect the longevity of our farming systems. Factors such as Water Use Efficiency, Sustainable Soil Management, Salinity avoidance strategies and other on farm practices covered by Best Management Practices  

Water Use Efficiency

Irrigators within the Lower Balonne strive to increase irrigation efficiency.  Benefits resulting from an efficient use of water include reduced groundwater problems and higher productivity.

Persistent lobbying of the Queensland government has seen legislation modified to allow referable storages to be built to a wall height of 8 meters instead of the previous 5 meter limitation. Irrigators are committed to increasing the average depth of their water storages, but the work is dependant on funding and moratorium limitations.

Most development within the Lower Balonne embraces the latest technologies, involving cell type storage constructions that enable waters to be amalgamated as volumes allow, thus reducing surface area and evaporation.

All irrigators employ a “closed system” which means water utilisation is increased and there is no loss of potentially contaminated tail water to river systems and wetlands. 

In relation to understanding water take from the river, it should be noted that it is a policy of Smartrivers that all water taken from the river should be metered and monitored.

For irrigators in the Lower Balonne to justify their use of water supplies and to maximise the potential to expand sustainably into new areas, water use efficiency initiatives are essential.  Smartrivers encourages irrigators and others in the industry to observe and maintain proper practices

Management of Soil Structures

Many irrigators in the Lower Balonne have embraced the need for better management of soil structures to improve water infiltration, increase natural nutrient exchanges, and also increase water storage holding capacities of soils.  This enables growing of a better crop and water is managed more efficiently. 

Soil is assessed for its suitability for irrigated cropping.  The surveys that have been completed in the Lower Balonne region use a combination of the traditional soil survey techniques and electromagnetic induction surveys.

Areas of soil that are considered stable and resilient enough to withstand the stresses of irrigated cropping are classed as suitable for that purpose.  Other areas of soil are used for rainfed cropping if suitable, or grazing, or left as native vegetation.

Soil used for irrigated cropping is managed in a way to maintain good soil structure.  The management regime includes: 

• Permanent beds in which wheel traffic lanes are separated from the zone where crops grow.  Tillage is used to prepare seedbeds and fertilizer is then confined to the cropped zone and the traffic zone is disturbed minimally by tillage.

• Stubble management practices that retain residues for the benefit of subsequent crops.

• Rotation that includes summer and winter crops to improve soil structure, as well as break disease cycles and use of subsoil moisture.

• Monitoring of soils physical condition and implementation of practices to overcome problems that are identified.

  Additional soil management practices may be recommended if shortcomings are identified in the soil survey.  These practices include:

• Tillage to disrupt compacted layers.

• Application of soil amendments such as gypsum, lime and occasionally, soil conditioners to improve the capacity of the soil to withstand the stresses imposed by irrigated cropping. 

  The aim of this regime is to maintain healthy soil structure while growing profitable crops.

Best Management Practice (BMP)

The cotton industry's Best Management Practices (BMP) program is a voluntary cotton industry initiative developed in 1997, which combines sound science and practical farm management. It aims to achieve sustainability by combining effective environmental protection and sound resource management.  BMP is the Australian cotton industry's commitment to reducing the impacts of cotton farming on the natural environment, neighbours, workers and the community.  Currently the manual covers the areas of: 

• Application of pesticides

• Storage and handling of pesticides

• Integrated pest management

• Farm design and management

• Farm hygiene

• Storage and handling of petrochemicals

The program although voluntary is being adopted by growers in all cotton producing regions.  At the end of 2002, approximately 80% of the cotton area in the St George and Dirranbandi districts was grown on farms which have completed the initial BMP (Best Management Practice) Compliance Audit.  100% of growers in the Dirranbandi district have undertaken the initial compliance audit and are proceeding through the audit program.  Dirranbandi is the only cotton growing area to achieve this success to date. 

For more information on the Cotton Industry's Best Management Practices program, contact Cotton Australia's St George office on (07) 46254038.

Salinity

Salinity has been branded as one of the major threats to the sustainability of land use with the Murray Darling Basin.  It threatens water quality in the river system and potentially impacts on the environmental value of streams, rivers and wetlands.  

River health cannot be assessed without taking salinity into account, because both terrestrial and aquatic ecosystems are sensitive to changes in salinity.

Due to the infancy of large-scale irrigation within the Lower Balonne, irrigators are placed in an excellent position with regard to investigating potential salinity impacts and to learn from the mistakes of earlier irrigation practices around Australia.       

Specific investigations being undertaken include the largest Airborne Geophysics Survey of its kind in Australia.  This programme was funded under the joint federal, state programme ‘National Action Plan For Salinity and Water Quality’. 

Smartrivers is a keen participant of this program and our involvement assures us that we are aware of the total process, from data collection to final interpretation, so as to understand the methodology and thus be accepting of the outcomes. 

This technology is often referred to as the “Ultra Sound” of the earth.  It allows us to understand the make up of the soils down as far as 150 to 200 meters.  Once the electromagnetic survey is completed, a series of calibration holes are drilled to ensure that the data from the airborne survey is calibrated.  In these holes, salinity is measured through pore fluids.  The result of all of this is that we can produce accurate depth slices indicating various levels of conductivity.

Once this has been done, it is possible to make a useful interpretation of the location of salt and also water resources in the landscape.  An enhanced soil map – making use of existing soil landscape information and the new detailed data from airborne gamma-radiometric imagery - is another product of this project.

A Salinity Steering Committee has been set up in the Lower Balonne to work with the Bureau of Rural Science and Queensland Department of Natural Resources and Mines.  The steering committee is comprised of representatives from a wide range of community interests. They include indigenous leaders, conservationists, graziers, irrigators and independent scientists.  Their roles include

• sounding board both for information and ideas from the scientist in the SMMS program and for concerns and ideas from local land and water users

• become pro-active in carrying information to the local community

• possibility to work with other groups, i.e. catchment groups to develop and implement management plans for the Lower Balonne.

Supporting the above process, many landholders are doing their own on farm work including on ground electromagnetic work (EM31) and soil investigation through good old-fashioned soil pits.  They are investigating areas that showing up as a high hazard on the Qld government Salinity Hazard map and showing high conductance on the airborne electromagnetic map now.  This work encompasses the top, middle and bottom areas of the Lower Balonne catchment.

Another important process is building a soil water model so as to establish the amount of deep drainage that we are getting under our existing cropping systems.  This tool quantifies the magnitude of deep drainage losses from unirrigated fields/irrigated fields, channels and storages.  It also determines the fate of the deep drainage water that leaks beneath our field.  Salt balance plans can be developed via this method as well.   This process is aided by the use of tools, such as mini lysimeters and C Probes.

The DNR&M are currently drilling a network of shallow ground water monitoring bores in the Lower Balonne.  This exchange of data will enhance the planning process in the field and help irrigators work towards a partnership approach to sustainability. 

Landholders and consultants alike believe that with increased knowledge and understanding, and the modification to some of our farming practices, we can minimise the impact of salinity on river health from irrigated agriculture in the Lower Balonne. 

The collective use of the above sustainable practices will come together to form what’s known as a land and water management plan, as well as establishing sustainable practices that will allow future generations to follow in our farming footsteps.