PROJECT NO. 125
Project Title |
Developing more sustainable farming systems for broadacre, rainfed cropping on Ferrosols |
Project Leader |
Mike Bell |
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Organisation |
Department of Primary Industries |
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Funding Body |
GRDC |
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Administration Contact |
Vicki Battaglia Department of Primary Industries Ph: 07 4639 8886 Fax: 07 4639 8881 |
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Commencement Date |
1 July 1999 |
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Completion Date |
30 June 2003 |
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Research Proposal Summary |
The central activities in this project are (i) the provision of technical support to farm groups investigating changes to their current farming system; (ii) the derivation and validation of benchmarks of system performance and indicators of sustainability; (iii) the continued development and application of APSIM to aid evaluation of new systems and technologies; and (iv) development and demonstration of a cropping system (of which peanuts are a component) that includes stubble retention, reduced tillage and appropriate management of key components of physical, chemical and biological fertility. Research initiation of this project can be classed as ‘Commissioned’, while R & D expenditure will be allocated in the following fashion – 20% Applied Research, 40% Experimental Development and 40% Demonstration and Extension. Methodologies employed in addressing the central project activities are listed below. (i) This project will allow the development of a focussed program of participative on-farm R, D & E to address issues of relevance to the continued productivity and sustainability of the various farming regions. It will aid in the design and implementation of these activities, provide analytical support in terms of sample analyses, data collection and interpretation and provide equipment to quantify or demonstrate treatment impacts. It will also assist in the provision of workshops to improve the understanding of complex soil/plant/environment interactions. Issues investigated by the groups will vary, but are likely to include fertiliser management strategies in conservation tillage systems, methods of overcoming subsoil infertility and compaction and organic matter management. Opportunities will be taken to add value to such work by ensuring results can be fully interpreted and by making additional measurements where appropriate. In addition to participating in these activities, monitoring of commercial fields will be undertaken to better quantify the role of sub-surface limitations (compaction, nutrient depletion and stratification of reserves, acidification) in crop performance. Small targeted experiments will be established at many such sites, generally comprising a comparison of farmer practices with one or two treatments designed at overcoming the constraint. (ii) There are a number of existing techniques for benchmarking system performance or indicating the sustainability of the current system. Examples of the former include nitrogen and water use efficiencies, whilst the latter may include levels of labile C or subsoil pH and K status. Further analysis of data from experimental plots in previous projects will allow derivation of such benchmarks for crops in Ferrosol farming systems. Once these analyses have been undertaken, these benchmarks will be promoted within farmer advancement teams and Top Crop groups as ways of indicating relative system performance. Once recognition of differences in system performance has been established, reasons for the differences can be investigated and solutions developed. (iii) Local validation of decision support tools for use by both advisers and farmers will be undertaken. One of the most important aspects of farming under rainfed conditions is the minimisation of risk, so tools like How Wet and How Often are of considerable interest. Other simple tools like combining soil testing with the prediction of nutrient requirements for various yield targets (eg. nutrient budgeting) will also be developed. Further development of the APSIM framework is required to better evaluate the riskiness and longer-term consequences of changes to production practices. In particular, development of an understanding of important biophysical interactions in the farming system is essential. A recent example has been the suggestion that hydrological imbalances and greater dryland salinity may result in the inland Burnett if increased rainfall infiltration is not matched by increased crop water use during non-traditional cropping periods (eg. spring and autumn). APSIM has also been used successfully in the Farmscape program (and now commercially) on the Darling Downs to help evaluate the impact of management decisions and proposed system changes in relation to climate variability. Some further development work (to allow APSIM to better cater for Ferrosol soils and the relevant crops in Ferrosol farming systems) will allow this tool to be used in these new cropping systems. Development and demonstration of a minimum tillage system that can be used by peanut growers is a key activity of this project. There will be a number of components to this work, all of which will involve farmer participation. Commercial production figures (from Top Crop groups and farm records) will be combined with experimental data to determine the optimum frequency of peanut cropping in the rotation (ie. every 2nd, 3rd or 4th year). This information will be combined with data on the necessary frequency of deep applications of lime and potash and deep ripping to counter subsoil problems that are emerging in minimum till systems and an ‘optimum’ rotation system devised. This rotation will be demonstrated on a small number of farms, with use of an appropriate planter developed in collaboration with local machinery manufacturers. During this phase, alternate strategies of peanut growing will be evaluated (eg. conventional till prior to peanuts, versus direct drill of peanuts followed by inter-row cultivation) in an otherwise no-till system. |
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Aims |
§ To develop a network of local farm advancement teams in north and south Queensland and to provide technical support to those teams in the establishment of on-farm trials investigating production and sustainability issues in the Ferrosol soils. § To support the continued development, application and promotion of decision support tools (including the APSIM systems framework) and key indicators or benchmarks of system performance for rainfed and irrigated farming systems on Ferrosols. § To continue the development, demonstration and promotion of practical solutions to productivity and sustainability issues that have emerged in both north and south Queensland farming systems. |
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Potential Outcomes |
§ A coordinated network of farm advancement teams on Ferrosol soils in north and south Queensland. These teams will be able to define production issues of concern for their local area, and collaborate with R&D providers to undertake simple on-farm trials to evaluate practical solutions to those issues. § A well-developed set of benchmarks to assess productivity of Ferrosol farming systems, along with key indicators to quantitatively define the relative sustainability of various farming options. § A locally validated suite of decision support aids that can be used to minimise the risk associated with rainfed cropping. This will include APSIM validated for Ferrosol soils (especially water, C and N balances) and relevant crops. § Quantification of the importance of sub-surface changes to Ferrosol fertility (nutrient depletion, acidification and compaction) in terms of crop performance, and demonstration of practical options for alleviating these constraints. § A successfully demonstrated cropping system (of which peanuts are a component) that includes stubble retention, reduced tillage and appropriate management of key components of physical, chemical and biological fertility. Implicit in this system would be improved soil organic carbon status. |
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Milestones |
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Budget |