Demonstration: assessing the effects of variable rate nitrogen


Research organisaton
Funding source

Trial details

Researcher(s) Nicole Dimos (SPAA), Riverine Plains Inc., Jason Collier , (Rand Fertilizers), Peter Baines (P Baines Agronomy), John Sykes (Rural Consulting) and , Leighton Wilksch (FSG)
Year(s) 2011
Contributor Society of Precision Agriculture Australia
Trial location(s) Site 4, Rand, NSW
Demonstration: assessing the effects of variable rate nitrogen locations

To compare the effects of using variable rate N in crop on the yield of crops in the Rand area. To determine if N rich strips and satellite maps could be used to better determine the need for N in crop.

Key messages

There was no visual response to applying N or yield. The N rich strips were also not obvious at the time of applying the N to the plots. This may have been a result of the moderate level of N in all zones, the dry spring and the time of application. From the DSN results, 20-60 kg/ha of N would have commended in August in the various zones to achieve the yield targets that were considered achievable at that time. The quality of the wheat produced was low (ASW due to low protein) indicating that insufficient N was applied. The economic analysis showed that the addition of N, lost money. The N rich strips were a useful guide to assessing that there would be no response to applying additional of N but not for assessing differing responses in different zones. It has not been possible to assess if satellite map were a useful guide to possible N response.

Lead research organisation Society of Precision Agriculture Australia
Host research organisation N/A
Trial funding source GRDC SPA000010
Related program N/A
Acknowledgments N/A
Other trial partners Angus MacNeil (Property owner)
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Crop type Wheat
Treatment type(s)
  • Fertiliser: Rate
Trial type Precision agriculture
Trial design Not applicable

Rand 2011

Sow rate or Target density 65 kg/ha
Sow date 18 May 2011 18 May 2011
Harvest date Not specified
Plot size Not specified
Plot replication Not specified

N rich stripe of 80 kg/ha of N (160 kg/ha of urea) was applie din late June across the site. • Rates of urea from 0 to 160 kg/ha (0-80 kg/ha of N) were applied in mid August just prior to growth stage Z31 of the wheat.


Glyphosate and Boxer gold

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Download results

Trial results Table 1

# Treatment 1
Grain yield (t/ha)
1 At 0 kg/ha N (as urea) 2.9
2 At 20 kg/ha N (as urea) 2.8
3 At 40 kg/ha N (as urea) 3.1
4 At 80 kg/ha N (as urea) 3
5 N-Rich strip (80 kg/ha N) + 0 kg/ha N (as urea) 2.9
6 N-Rich strip (80 kg/ha N) + 20 kg/ha N (as urea) 2.6
7 N-Rich strip (80 kg/ha N) + 40 kg/ha N (as urea) 3.2
8 N-Rich strip (80 kg/ha N) + 80 kg/ha N (as urea) 2.9

Grain yield t/ha

Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Site 4, Rand, NSW Not specified
Derived trial site soil information
Australian Soil Classification Source
Trial site Soil order
Site 4, Rand, NSW Sodosol
National soil grid Source
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.

Site 4, Rand NSW


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.

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Trial last modified: 20-09-2019 17:36pm AEST