Economic and financial analysis of precision variable rate applications (VRA) of nitrogen


Research organisaton
Funding source

Trial details

Researcher(s) Sosheel Godfrey
Tim Hutchings
Thomas Nordbloom
Cassandra Schefe
Year(s) 2017
Contributor Riverine Plains
Trial location(s) Yarrawonga, VIC
Economic and financial analysis of precision variable rate applications (VRA) of nitrogen locations

To quantify the within-paddock variability of yields using records from paddocks in the Yarrawonga and Dookie areas and to quantify the impact of VRT-nitrogen on longterm, whole-farm financial risk.

Key messages

• The use of variable-rate technology for nitrogen (VRT-nitrogen) application had mixed gross margin results given measured wheat yields, protein levels, calculated income and nitrogen costs in the nitrogen-rate trials undertaken at Yarrawonga and Dookie during 2017.
• Based on initial results at Yarrawonga and Dookie (using 19 and 13 years of wheat and canola yield responses to growing season rainfalls, respectively), the costs of conducting variable rate applications of nitrogen would require crop yields to increase by about 1%, or applied nitrogen costs to be reduced by at least 70%, before the approach breaks even over time.
• High overhead cost structures increase the risk of negative farm income. As VRT increases overhead costs, reviewing overall cost structures before adopting the technology is advisable.

Lead research organisation Riverine Plains
Host research organisation Riverine Plains
Trial funding source GRDC RPI00009
Related program N/A

Thank you to the cooperating farmers, who generously allowed access to their detailed header-yield estimates and
who have also been generous with their time in helping us understand locally-relevant costs and equipment
replacement facts.
This analysis was carried out as part of the GRDC investment Maintaining profitable farming systems with
retained stubble in the Riverine Plains region project.
Thanks also to Brendan Torpy and Meera Dawson (Precision Agriculture), Claire Robinson (Hutcheson and Pearce) and
Craig Poynter, GIS & Remote Sensing, Spatial Data Analysis Network (SPAN), Charles Sturt University.

Other trial partners Graham Centre for Agricultural Innovation, Charles Sturt University
Download the trial report to view additional trial information


Crop type Cereal (Grain): Wheat
Treatment type(s)
  • Farm operations: Economics
  • Fertiliser: Timing
Trial type Experimental
Trial design Unknown

Yarrawonga 2017

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Download the trial report to view additional method/treatment information
Trial source data and summary not available
Check the trial report PDF for trial results.
Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Yarrawonga, VIC Not specified
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Yarrawonga, VIC Sodosol
Soil Moisture Source: BOM/ANU
Average amount of water stored in the soil profile during the year, estimated by the OzWALD model-data fusion system.
Year Yarrawonga VIC
2017 567.5mm
2016 599.8mm
2015 597.1mm
2014 586.7mm
2013 573.0mm
2012 589.8mm
2011 592.9mm
2010 605.2mm
2009 562.9mm
2008 560.4mm
2007 538.8mm
2006 557.8mm
2005 583.2mm
2004 557.7mm
2003 547.9mm
2002 524.2mm
2001 511.4mm
2000 461.9mm
National soil grid Source: CSIRO/TERN
NOTE: National Soil Grid data is aggregated information for background information on the wider area
Actual soil values can vary significantly in a small area and the trial soil tests are the most relevant data where available

Soil properties



Derived climate information

No observed climate data available for this trial.
Derived climate data is determined from trial site location and national weather sources.

Yarrawonga VIC


Some data on this site is sourced from the Bureau of Meteorology

SILO weather estimates sourced from
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol 16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.

Trial report and links

2017 trial report

Trial last modified: 09-07-2019 16:00pm AEST