 Three videos were were developed as part of Best Practice activities: Crop Preparation Systems, Cropping Sequences and Salinity. Completing the Vision is a very informative video about the pipeline project. Click on the name to read the full description of the video contents. Copies may be obtained from: Sustainable Development Unit Natural Resources & Environment (NRE)Bendigo Phone: 03 5430 4444 Crop Preparation Systems This video outlines the options that Mallee farmers could consider in preparing land for cropping. It highlights the need to manage the cropping program according to the capability of the soil. It is recommended that Mallee farmers use an integrated approach to prepare for cropping.
To control erosion on lighter soils different management techniques are required.
Chemical management of weeds helps reduce the need for tillage. However, any form of weed control will lead to weed-selection. Selection of different chemicals and crop sequences can be used to manage resistance. Failure to use alternative chemical groups may lead to chemical resistant weeds. Careful selection of chemicals for weed control is critical. Integrated management using chemicals, grazing, and cultivation has proven to be the best approach. The application of these options will vary from year to year according to climatic conditions. Where cultivation is practiced the use of a blade or chisel plough helps maintain soil structure. There is increasing acceptance of direct drilling into stubbles and chemically prepared soils. This requires additional capital outlay to purchase or modify equipment. Some unproductive soils may best be kept out of the cropping program, as they are key recharge areas contributing to salinity. Trees, shrubs, saltbush and lucerne can be strategically used in these areas. Where can we learn more about these farming systems that help us to farm more sustainably? The Mallee Sustainable Farming Project has been conducting trials on these issues for the past three years. They have published reports on the implications of using these systems in the specific conditions experienced in the Mallee. The Cropping Groups, Natural Resources and Environment and Agribusiness are other sources of advice. Cropping systems can incorporate livestock grazing to control weeds, manage stubbles and provide an additional income stream for the farm. The preparation we choose for cropping in the Mallee is a result of our careful consideration of rainfall, paddock history, soil types and exposure to salinity. All these factors can influence our decision-making. Mallee farmers are flexible and need to be, as conditions vary dramatically from year to year. BACK TO TOP Crop Sequences This video explores key issues relating to sequences or rotations of crop types and varieties and the agronomic and economic gains that can be achieved from making good decisions about cropping sequences. Farming in the Mallee is a high-risk activity. Farmers have options to help them to achieving high yields and maximum water use efficiency. Crop root and leaf diseases can severely impact on productivity. Controlling these problems is a management issue - getting it right is like the pieces of a jigsaw coming together. Where crops of similar characteristics are grown consecutively pest plants and diseases thrive. To manage these problems naturally a well considered cropping sequence (rotation) is required. What works in one paddock will not necessarily work in another. Sequences that work in paddocks with good heavy soils will not work in less fertile, lighter soil areas. Farmers need to plan crop sequences carefully, while also considering factors like soil types and current climatic conditions. There is a need to understand what is happening under the ground. Factors like; salinity, sodoicity, boron, limestone and soil structure can all limit yields. It is then possible to respond to particular problems with suitable crop varieties and soil management. Root diseases like Cereal Cyst Nematode, Root Lesion Nematode and Take-all need to be closely monitored. The widest possible length of time between the planting of similar monoculture crops is desired to prevent any particular organism from becoming detrimental to crop performance. Specific crops such as canola, peas and lupins can make them excellent "break" crops preventing the build up of cereal disease. Leaf diseases are spread in a similar way and must also be controlled. Growing different crops provides the opportunity to target persistent weeds. Using deep-rooted crops in the sequence helps to control potential watertable recharge and the threat of salinity. Using a variety of chemical sprays with crop sequences alleviates the threat of weed resistance and possible limitations on future cropping options. Careful management of tillage practices and trash retention enhances soil structure and minimises erosion. Nutrient management is critical in achieving high yields. Mineralisation in wet summers can release large amounts of nutrients. "Know your soils". Objective nutrient measuring using soil tests could save you thousands of dollars in fertiliser costs. Pasture provides a low-risk, low-cost option in cropping sequences. It facilitates weed control, provides soil nitrogen and is a good cereal disease break crop. Grazing animals can also play an important part in the control of trash and weeds. Managing a farm in the Mallee is a high-risk business, and to make it profitable and to maintain the health of your property you have to get all the pieces in place. BACK TO TOP Dryland Salinity “Salinity is the single greatest threat currently facing Victoria’s environment”. In the Mallee, dryland salinity and rising watertables are a significant and worsening issue. Dryland salinity affects not only farms and land actually going out to salt, but rivers and their water quality, roads and other infrastructure, farm and town water supplies, and wildlife habitat. Dryland salinity does and will continue to affect the entire community. The Victorian Mallee covers 4.3 million hectares. The Mallee produces 50% of the cereal grown in Victoria. Almost 40% of the Mallee is public land, with a large proportion protected in National Parks. The major landforms that we see in the Mallee are rolling dunes and ‘swales‘. The average annual rainfall varies from 250mm in the north to up to 400mm in the south. Up to 40% of this rain, falls during the summer. Before European settlement, the native vegetation that existed across the landscape used up much of the rainfall before it soaked deeper into the ground. Agricultural settlement of the Mallee began in the 1880’s. Land-use changes since European settlement has not only seen the widespread clearing of our native vegetation, but the introduction of annual, shallow rooted crops and pastures. This has resulted in less rainfall being used, allowing water to seep down through the soil. The water reaches a layer of rock or clay that will not let it go any further. The soil then begins to saturate from the bottom up. Water adding to the watertable in this way is called RECHARGE. The top level of the saturated zone is called the WATERTABLE. There are many salts stored naturally in the soil. As we allow more and more water to recharge the watertable, it rises naturally in the soil profile, and the stored salts in the soil are dissolved or ‘mobilised’. The rising watertable slowly brings them to the surface creating a salinity problem. When the watertable reaches the ground surface, it DISCHARGES out into the landscape. “As the watertable rises, low lying areas like this are likely to suffer from discharge. Where the watertable rises to within 2 metres of the surface, that where the damage is occurring. Capillary action brings the saline groundwater into the root zone of crops. Crops begin to thin out, yields will drop and the area will progressively develop into a salt scald. Salinity is a natural part of the Mallee landscape. Features such as Raak Plain and Lake Tyrrell formed naturally as part of the delicately balanced groundwater system that exists in the Mallee. They are examples of ‘regional salinity’ which has always been part of our natural drainage system. ‘Locally salinity’ occurs where the watertable nears the surface in low lying area or on rises where there is a clay layer under the soil which forces the groundwater to move sideways and to discharge at the foot of the dune. The watertable is rising across most of the West Mallee at a rate of approximately 20mm each year. It is estimated that in fifty years the total area affected will be 330,000 hectares. This would mean that 10% of private farming land and 5% of public land would be lost to salt. These new areas of salting are projected to cause the Mallee economy an annual loss in gross agricultural production of $25 million. Local induced salinity occurs in areas where a clay layer sits below the ground surface. This often occurs in sand dunes and instead of the water travelling downwards, the groundwater in the perched watertable hits the clay layer and flows sideways. If the topography is right, this groundwater can end up discharging at the toe of the dune. In the most severe cases local salinity can also lead to the formation of salt pans. A dramatic example of local salinity is seen in the seepage from the open channel system, which is used to supply stock and domestic water for much of the Mallee. The Northern Mallee Pipeline is progressively reducing this damage. Stopping local salinity relies on farmers making the most use of the rain that falls on their land, so that as little rain as possible ends up reaching the watertable. Mallee farmers can help reduce the impact of local salinity by improving our cropping systems to maximise yields and the use of water that falls on our land. ·
These measures will also improve the productivity and health of your farm. The Mallee Dryland Salinity Management Plan was developed in 1993 and together with the Government support document, provides the framework by which salinity is managed in the Mallee. Incentives are available under the plan to assist farmers with some on-ground works. “There has been a lot of good work done and there are options for farmers to battle the ‘Grim Creeper’. Let’s work together to ‘Halt the Salt’ in the Mallee” BACK TO TOP Completing the Vision****** text needed BACK TO TOP ABOUT | PROJECTS | PUBLICATIONS | CONTACT | LINKS | HOME |