Early sowing and the interaction with row spacing and variety in first wheat crops under full stubble retention


Research organisaton
Funding source

Trial details

Researcher(s) Nick Poole and Michael Straight (FAR Australia)
Year(s) 2016
Contributor Riverine Plains
Trial location(s) Site 1, Yarrawonga, VIC
Early sowing and the interaction with row spacing and variety in first wheat crops under full stubble retention locations

To investigate the interaction between early sowing and row spacing and variety in first wheat crops under full stubble retention.

Key messages

• Four wheat trials sown during mid-April 2014 and 2015 showed no difference in grain yield or quality as a result of being grown on 22.5cm, 30cm and 37.5cm row spacings, when averaged across four varieties (Bolac/Kiora, Lancer, Trojan and EGA Wedgetail).
• The 2016 trial sown during mid-April again showed no difference in yield between 22.5cm and 30cm row spacings, however yields were significantly less with the widest row spacing (37.5cm).
• Trial yields in 2016 were 1.5t/ha higher than 2014 and 2015 (3–4.25t/ha), with the higher yield potential likely to be a key factor in the poor performance of the widest row spacing (37.5cm).
• The Riverine Plains Water Use Efficiency (WUE) project (2009–13) showed that when crops were sown in the traditional sowing window, the 22.5cm spacing was more successful than the 30cm spacing, except in drier years with lower yield potential (2.5–3.0t/ha).
• In the three years (2014–16) of trialling row spacing on early-sown crops, crops grown on a 22.5cm row spacing produced more dry matter (DM) than crops grown on wider rows. However, the 2016 trial was the first to show a yield disadvantage to the widest
row spacing (37.5cm) when sown early.
• As a result of lower yields, the 37.5cm row spacing gave significantly poorer water use efficiency (WUE) than 30cm row spacing, with a greater proportion of calculated water losses (soil evaporation, drainage or unused water).
• A barley row spacing trial, sown at the same time alongside the wheat, provided some useful comparative observations during 2016, with La Trobe barley producing higher DM and yields than wheat with a harvest index (HI) of approximately 50% compared with wheat at 40%.

Lead research organisation Riverine Plains
Host research organisation Riverine Plains
Trial funding source GRDC RPI00009
Related program Maintaining profitable farming systems with retained stubble

Thank you to our farmer co-operators, J and S Bruce Barooga, NSW and Telewonga Pty Ltd, Yarrawonga, Victoria.

Other trial partners FAR Australia
Download the trial report to view additional trial information


Crop type Wheat
Treatment type(s)
  • Sowing: Row spacing
  • Variety: Type
Trial type Experimental
Trial design Blocked

Yarrawonga 2016

Sow date 14 April 2016
Harvest date 11 December 2016
Plot size Not specified
Plot replication Not specified

host farmer paddock management


host farmer paddock management


host farmer paddock management

Download the trial report to view additional method/treatment information

Download results

Trial results Wheat variety growth traits at Yarrawonga in 2016

@T1: @T2: @T3:
# Treatment 1
Cereal tillers (tillers/m2) Establishment plants (plants/m2) Hectolitre weight (kg/hL) Grain yield (t/ha) Head abundance (heads/m2) Protein (%) Screenings <2mm (%) Dry matter (t/ha) Nitrogen uptake (kg N/ha) Nitrogen uptake (kg N/ha) Dry matter (t/ha) Dry matter (t/ha) Nitrogen uptake (kg N/ha)
1 Wedgetail 549 129 79.5 5.45 454 9.4 2.6 1.66 60 108 10.94 12.89 113
1 Kiora 435 132 80.2 5.8 385 8.5 2.6 1.78 64 78 11.96 11.78 101
1 Lancer 373 112 80 5.33 323 9.2 2.4 1.36 56 91 10.33 10.16 66
1 Trojan 431 144 80 5.49 372 9.6 2.1 1.79 62 99 12.28 12.44 122

Grain yield t/ha


Cereal tillers tillers/m2


Dry matter t/ha


Establishment plants plants/m2


Head abundance heads/m2


Hectolitre weight kg/hL


Nitrogen uptake kg N/ha


Protein %


Screenings <2mm %

Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Site 1, Yarrawonga, VIC Not specified
Derived trial site soil information
Australian Soil Classification Source
Trial site Soil order
Site 1, Yarrawonga, VIC 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



Site 1, Yarrawonga VIC 2016

Observed climate information

Rainfall trial gsr (mm) 604mm

Derived climate information

Site 1, Yarrawonga VIC


Some data on this site is sourced from the Bureau of Meteorology

SILO weather estimates sourced from https://www.longpaddock.qld.gov.au/silo/
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: 29-08-2019 14:06pm AEST