Nick Poole and Michael Straight (FAR Australia)
Site 1, Yarrawonga, VIC
To investigate the interaction between early sowing and row spacing and variety in first wheat crops under full stubble retention.
• 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||
|Host research organisation||
|Trial funding source||GRDC RPI00009|
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|
|Sow date||14 April 2016|
|Harvest date||11 December 2016|
|Plot size||Not specified|
|Plot replication||Not specified|
|Herbicide||<p>host farmer paddock management</p>|
|Insecticide||<p>host farmer paddock management</p>|
|Fungicide||<p>host farmer paddock management</p>|
||Head abundance (heads/m2)||Protein (%)||Screenings <2mm (%)||Cereal tillers (tillers/m2)||Establishment plants (plants/m2)||Hectolitre weight (kg/hL)||Grain yield (t/ha)||Nitrogen uptake (kg N/ha)||Dry matter (t/ha)||Dry matter (t/ha)||Nitrogen uptake (kg N/ha)||Nitrogen uptake (kg N/ha)||Dry matter (t/ha)|
|Rainfall trial gsr (mm)||604mm|
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.