Managing nutrition in sandy soils to close the yield gap


Research organisatons
Funding sources

Trial details

Researcher(s) Bill Davoren (CSIRO)
Rick Llewellyn (CSIRO)
Therese McBeath (CSIRO)
Willie Shoobridge (CSIRO)
Year(s) 2015
Contributor Mallee Sustainable Farming Inc.
Trial location(s) Site 5, Loxton, SA
Managing nutrition in sandy soils to close the yield gap locations

Sandy soil types of the Northern Mallee often underperform despite good weed management and increased inputs of nitrogen and sulphur. There is still a yield gap that can be addressed, with anecdotal evidence of unused water commonly remaining in the soil at depths of approximately 60cm at harvest. In 2014 we set in place a diagnostic procedure to attempt to identify the production limitations on a poor-performing dune at the MSF site near Loxton. Characterisation of the plant available water capacity allowed us to calculate water use efficiency which suggested that the 2014 plots were operating well below industry benchmarks. Penetration resistance was measured to be greater than the threshold predicted to impede root exploration at 20-45 cm depth, suggesting that compaction might be limiting yield. Replicated harvest test strips on and off of wheel tracks measured at three locations in 2014 showed a significant effect of the wheel track compaction at one location only. The site is alkaline sand and pre-sowing soil tests in 2014 indicated relatively low soil test values for sulphur (S) and zinc (Zn). In-season tissue tests indicated marginal status for nitrogen (N), Zn and copper (Cu) and test strips with additional N showed a positive response. The likely primary limitations to production identified were compaction and nutrition.

Key messages
  • 40 kg N/ha applied upfront was the best yielding treatment for 2015, with the best protein results where the 40 Kg of N was applied as Urea.
  • We found that 20 kg N/ha applied as a Zn enriched Urea product achieved a yield close to 40 kg N/ha as straight urea and we plan to test this treatment again in 2016.
  • The timing and form of S application did not have any effect in 2015.
Lead research organisation Commonwealth Scientific and Industrial Research Organisation
Host research organisation N/A
Trial funding source CSIRO
Trial funding source GRDC MSF00003
Related program N/A

Thanks to Bulla Burra for their generous support in hosting the trial, and to Robin Schaeffer, Matthew Whitney, Michael Moodie, Jeff Braun and Lou Flohr for discussions around trial design. Thanks to Colin Rivers and Ros Baird for preparing granular Zn fertilisers. Funding for this work has been from the GRDC (MSF00003) and CSIRO Agriculture.

Other trial partners Not specified
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Crop type Wheat
Treatment type(s)
  • Fertiliser: Type
  • Fertiliser: Rate
  • Fertiliser: Timing
Trial type Experimental
Trial design Replicated

Loxton 2015

Sow date 6 May 2015 6th May 2015
Harvest date Not specified
Plot size Not specified
Plot replication 4

Plots were sown at Loxton with Mace wheat on the 6th May and all plots received 10 kg P/ha as triple superphosphate with the following nutritional treatments applied with four replicates: Control- P only 20N Urea @sow + 20N Zn enriched Urea@ GS14/22 20N Urea @sow 20N Urea @sow + 20N Urea@GS31 40N Urea at sow 20N Urea @sow+20S gypsum pre-sow 20N Zn enriched Urea @sow (Zn Oxide)# 20N Urea @sow+20S gypsum@ GS14/22 20N Urea + Zn blend @sow (Zn Oxide) 20N Urea @sow+20S/20 N SOA+ Urea@ GS14/22 20N urea + Foliar Zn @ 2-3 leaves (farmer Zn, Zn Sulfate) 20N Urea @sow+4 S SOA@ GS14/22 (replacement S) 20N Urea @sow + 20N Urea@GS14/22* 20N Urea @sow + 20N Urea@ GS14/22+20S gypsum@ GS14/22 #This product is not commercially available in Australia *GS14/22-early tillering, GS31-first node

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Download results

Trial results Table 1

# Treatment 1
Protein (%) Dry weight (first node) (t/ha) Grain yield (t/ha) Dry weight (anthesis) (t/ha)
1 Control 9.54 0.82 0.96 1.62
2 20N Urea @ sow 9.13 1.16 1.41 2.29
3 40N Urea @ sow 10.16 1.15 1.66 2.57
4 20N Zn enriched urea @ sow 9.13 1.21 1.53 2.56
5 20N Urea + Zn blend @ sow 9.27 1.19 1.38 2.43
6 20N Urea + foliar Zn @ 2-3 leaves 9.03 1.16 1.39 2.42
7 20N Urea @ sow + 20N Zn enriched Urea @ GS14/22 9.93 1.23 1.61 2.54
8 20N Urea @ sow + 20N urea @ GS31 9.6 1.08 1.55 2.5
9 20N Urea @ sow + 20S gypsum @ GS14/22 10.45 1.11 1.56 2.38
10 20N Urea @ sow + 20N urea @ GS31 8.88 1.13 1.29 2.44
11 20N Urea @ sow + 20S gypsum pre-sow 9.43 1.24 1.35 2.72
12 20N Urea @ sow + 20N urea + 20S gypsum @ GS14/22 9.93 1.26 1.55 2.47
13 20N Urea @ sow + 20S/20N SOA + urea @ GS14/22 9.63 1.18 1.59 3.02
14 20N Urea @ sow + 4 S SOA @ GS14/22 9.25 1.04 1.37 2.69

Grain yield t/ha


Dry weight (anthesis) t/ha


Dry weight (first node) t/ha


Protein %

Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Site 5, Loxton, SA Not specified
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Site 5, Loxton, SA Vertosol
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 Site 5, Loxton SA
2015 153.0mm
2014 202.8mm
2013 156.4mm
2012 211.4mm
2011 269.8mm
2010 210.8mm
2009 136.3mm
2008 145.5mm
2007 174.9mm
2006 191.1mm
2005 225.9mm
2004 163.2mm
2003 172.2mm
2002 144.1mm
2001 173.7mm
2000 196.6mm
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.

Site 5, Loxton SA


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: 25-06-2019 10:28am AEST