In-paddock variability — a snapshot and lessons learnt


Research organisaton
Funding source

Trial details

Researcher(s) Peter Dahlhaus
Ben Fleay
Cameron Grant
Les Janik
Dean Jones
Nathan Robinson
Cassandra Schefe
Ryan Walker
Year(s) 2017
Contributor Riverine Plains
Trial location(s) Yarrawonga, VIC
In-paddock variability — a snapshot and lessons learnt locations

The aims of the PA component of the GRDC Stubble project were to:

• deliver a pilot project to understand how soil parameters, including PAW, vary across a paddock and understand
whether current PA datasets can correlate with PAW

• connect variations in soil moisture with nitrogen supply

• demonstrate the use of NDVI to inform variable rate applications of nitrogen

• determine the economic value of variable rate nitrogen application across paddocks, based on zones

Key messages

• Electromagnetic (EM) zoning was strongly related to differences in pH at 10–30cm depth in two out of three paddocks.
• All three paddocks showed variability in chemical properties, with the EM zoning showing good separation of chemical properties between zones. This provides confidence that the zoning was suitable.
• Variability in plant growth needs to be examined ‘holistically’ rather than just focussing on one variable. While a paddock may show variation in plant available water (PAW), it may be that sodicity or subsoil acidity is the key limiter in plant performance, not water availability per se.
• Existing precision agriculture (PA) datasets, in conjunction with selected chemistry sampling, can be used to indicate relative change in PAW across paddocks, but not the actual volume of water storage.

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

This work was carried out as part of the PA component of the GRDC investment into the Maintaining profitable farming
systems with retained stubble in the Riverine Plains region project. Thank you to our host farmers —Trevethan Family Farms, the Inchbold family, Harmer Farms and Lilliput Ag.

Other trial partners University of Adelaide, School of Agriculture, Food & Wine; Centre for eResearch and Digital Innovation; Federation University Australia; Australian Precision Ag Laboratory; Precision Agriculture
Download the trial report to view additional trial information


Crop type Cereal (Grain): Wheat
Treatment type(s)
  • Management systems: Precision Agriculture
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 16:02pm AEST