Variable rate nitrogen trial – maintaining profitable farming systems with retained stubbles in the Upper North of SA


Research organisatons
Funding source

Trial details

Researcher(s) Matt Foulis (Northern Ag)
Year(s) 2014
Contributor Upper North Farming Systems
Trial location(s) Site 4, Booleroo Centre, SA
Variable rate nitrogen trial – maintaining profitable farming systems with retained stubbles in the Upper North of SA locations

To investigate the possible advantages of varying nitrogen rates over different soil types on a field in the Upper North region.

Key messages
  • Each soil zone was nitrogen responsive at varying levels.
  • Low EM zones (sands and sand-loams) were very responsive - 41-61% increase in yield achieved by applying the top rate of urea.
  • High EM zones (clay-loams) were moderately responsive - 10-22% increase in yield achieved.
  • Applying high rates of nitrogen to high EM (clay-loam) zones proved to be un-economical.
Lead research organisation Northern Ag
Host research organisation Upper North Farming Systems
Trial funding source GRDC
Related program Maintaining profitable farming systems with retained stubble

Michael Wells, Yield data analysis and trial setup - PCT Ag, Jessica Wells, trial setup - Pringles Crouch, David Kumnick, Grower and data collection.

Other trial partners Not specified


Crop type Barley
Treatment type(s)
  • Fertiliser: Rate
  • Soil: Type
Trial type Experimental
Trial design Unknown

Booleroo Centre 2014

Sow rate or Target density 60kg/ha
Sow date 22 April 2014
Harvest date Not specified
Plot size Not specified
Plot replication Not specified

Seeding Nutrition 19:13:0:9 @ 120kg/Ha Post Em Nutrition Urea @ 50kg/Ha 29/5/2014 Urea (Trial) @ 0,50,100kg/Ha 14/6/2014

Soil amelioration

Seeding System Knifepoint & Press wheels

Download results

Trial results Table 1

# Treatment 1
Treatment 2
Grain yield (t/ha)
1 (SAND) EM40.7 Urea 0kg/ha 2.2
2 (SAND) EM40.7 Urea 50kg/ha 2.9
3 (SAND) EM40.7 Urea 100kg/ha 3.5
4 (SANDYLOAM) EM72.9 Urea 0kg/ha 3.1
5 (SANDYLOAM) EM72.9 Urea 50kg/ha 3.6
6 (SANDYLOAM) EM72.9 Urea 100kg/ha 4.5
7 (CLAYLOAM) EM103.8 Urea 0kg/ha 3.4
8 (CLAYLOAM) EM103.8 Urea 50kg/ha 4
9 (CLAYLOAM) EM103.8 Urea 100kg/ha 4.1
10 (CLAY) EM145.3 Urea 0kg/ha 3.1
11 (CLAY) EM145.3 Urea 50kg/ha 3.6
12 (CLAY) EM145.3 Urea 100kg/ha 3.5

Grain yield t/ha

Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Site 4, Booleroo Centre, SA Various
Derived trial site soil information
Australian Soil Classification Source
Trial site Soil order
Site 4, Booleroo Centre, SA 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, Booleroo Centre 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.

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Trial last modified: 27-06-2019 11:46am AEST