*Note - this report may contain independently supported projects which complement the work in this GRDC research program.

Take home messages

Tramline farming (TLF) has the potential to reduce fuel use by about 25% and fertiliser use by 10% translating to a 10% reduction of greenhouse gas emissions on a northern wheatbelt farm. A potential of 200 tonnes of CO₂-e could be saved annually for every tonne of extra grain production by TLF (an estimated 10% yield benefit on 2.5 t/ha).

Aims

• Quantify benefits of TLF for reducing fuel and fertiliser costs including the potential to reduce greenhouse gas emissions.
  
  
• Identify the relative benefits of better rolling resistance on tramlines in comparison to reduced running distance.

Methods

Fuel flow meters (McNaught) on farm tractors and harvesters were used on a farm in the Geraldton district and a farm in the Lake Varley district for direct measurements of fuel use on or off tramlines.

To support the research farm fuel costs from three farms with excellent records were collated prior to and after adopting TLF to estimate whole farm fuel savings. Calculations of fuel savings from better traction more efficient operation patterns and less running distance ('dead running') were made for different patterns of paddock operation (up and back or round and round). See extended paper for calculations.

Survey data was used to estimate the nitrogen fertiliser savings on farms converted to tramlines. The survey of 42 growers approximately 80 per cent of growers known to be using or planning to use tramlines was made by telephone during the 2003 season.

Results

For the three farms that adopted TLF there was an average 28% reduction of whole farm fuel use per hectare. However this information does not clarify the relative effects of better traction compared to less travel distance.

The fuel meters used on machinery from two farms showed most of the fuel savings come from seeding and harvesting operations with the best savings from uphill operations with high draft. The combination of three sprayings one spreading one seeding and one harvesting operation resulted in an estimated savings of 844 L/1000 ha or 17%. Including only the seeding spraying and spreading operations gave estimated savings of 12% (refer to extended paper Table 1 for detailed results). This is about half of the savings reported from the whole farm estimates. However further data for harvest operations are needed before we can be confident of the fuel savings at harvest.

The relative effect of better traction when using DGPS autosteer but not matching the header compared to more efficient working patterns is 1.21 the larger proportion coming from better traction.

More efficient working patterns for TLF are achieved by using a guidance system. Calculations estimate 'dead running' was least for up and back work and very dependent on paddock size.

Autosteer up and back typically reduces operating area by 10% which includes dead running and less overlap between swaths. Thus swath overlap must be about 5% normally and reduced to 0 by autosteer. If we assume that mechanical guidance may be an improvement in swath overlap of 2% then fuel and fertiliser saving by mechanical guidance may be 7%.

Values of estimated benefits from better traction and less 'dead running' are used in Table 1 to estimate the value of fuel and fertiliser saving in terms of dollars and greenhouse gas emissions. Parameters come from the Greenhouse Gas emissions spreadsheet (Rodriquez et al. 2003) and TLF survey 2003. The survey showed about 135000 ha in some form of tramline 20000 ha fitted to the header and 80000 ha matching only the boomspray and seeder the rest is being developed to fit tramlines. There were also 68000 ha with autosteer and 66000 with other guidance. The average units of nitrogen/ha applied by these growers were 61 kg N/ha and the average fertiliser value was $72/ha.

Conclusions

• TLF has the potential to reduce fuel use by about 25% and fertiliser use by 10%. This translates to a 10% reduction of greenhouse gas emissions on a typical northern wheatbelt farm.
  
  
• Current tramline users are helping to reduce greenhouse gas emissions by about 3 000 t/CO₂ equivalent in 2003. This may be used to develop market advantages for our exported grain products by contributing to our 'Green' image.
  
  
• The measured fuel savings of better traction were 60% of the total measured and estimated savings (that includes benefits from more efficient working patterns).
  
  
• TLF can increase yields of a northern sandplain farm by about 10%. With a potential greenhouse gas saving of about 50 t/y by TLF this translates to 200t of carbon dioxide equivalent abated for each tonne of better grain production in TLF.

Acknowledgments
The Sustainable Energy Development Office (SEDO) of the Department of Energy of Western Australia project C359MSEDO. Grains Research and Development Corporation DAW 718. Glen Riethmuller and Anne Bennett for technical discussions and growers interviewed in the survey.