Variable rate phosphorus and ntrogen trials on YP

CC BY 4.0

Research organisaton
Funding source

Trial details

Researcher(s) Nicole Dimos (SPAA)
Peter Treloar (Precision Ag Services )
Sam Trengove (Trengove consulting)
Simon Wheare (Growers)
Leighton Wilksch (Landmark Precision Ag Agronomist)
Year(s) 2010
Contributor Society of Precision Agriculture Australia
Trial location(s) Ardrossan, SA
Variable rate phosphorus and ntrogen trials on YP locations
  • To evaluate the potential of phosphorus replacement as a method of applying variable rate fertiliser.
  • Compare EM38 and NDVI as guides for nitrogen application and illustrates how simple farmer trials can be used to assess the benefits of variable managment.
Key messages

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits.

Lead research organisation Society of Precision Agriculture Australia
Host research organisation N/A
Trial funding source GRDC SPA000010
Related program N/A

This project was funded by the Grains Research and Development Corporation (GRDC) and run in conjuncion with Caring for our Country and Dept. Environment and Natural Resources

Other trial partners Topcon, Caring for our Country and Dept. Environment and Natural Resources.
Download the trial report to view additional trial information


Crop type Wheat
Treatment type(s)
  • Fertiliser: Rate
Trial type Precision agriculture
Trial design Not applicable

Ardrossan 2010

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

Download results

Trial results Table 1

# Treatment 1
Grain yield (t/ha)
1 0kg/ha Urea 4.25
2 70kg/ha Urea 4.96
3 70kg/ha Urea 4.88
4 70kg/ha Urea 4.97
5 140kg/ha Urea 5.71

Grain yield t/ha

Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Ardrossan, SA Not specified
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Ardrossan, SA Calcarosol
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 Ardrossan SA
2010 329.9mm
2009 306.4mm
2008 299.0mm
2007 308.6mm
2006 320.2mm
2005 304.2mm
2004 303.9mm
2003 317.3mm
2002 304.4mm
2001 328.4mm
2000 327.8mm
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.

Ardrossan SA

NOTE: Exact trial site locality unknown - Climate data may not be accurate

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 last modified: 30-09-2019 16:16pm AEST