Barley grass management in retained stubble systems - farm demonstrations

2015
CC BY 4.0

Research organisatons
Funding source

Trial details

Researcher(s) Amanda Cook (SARDI)
Year(s) 2015
Contributor Eyre Peninsula Agricultural Research Foundation
Trial location(s) Minnipa Agricultural Centre, SA
Related trials
Barley grass management in retained stubble systems - farm demonstrations locations
Aims

The GRDC ‘Maintaining profitable farming systems with retained stubble - upper Eyre Peninsula’ project aims to improve farm profitability while retaining stubble in farming systems on upper Eyre Peninsula (EP). Weed control in stubble retained systems can be compromised where herbicide efficacy is limited due to higher stubble loads, especially for preemergent herbicides. Current farming practices have also changed weed  behavior with later germinating barley grass genotypes now present in many paddocks on the Minnipa Agricultural Centre (MAC) (B Fleet, EPFS Summary 2011). Several MAC farm demonstrations  were undertaken in 2014 to address barley grass weed issues including later germinating types and barley grass resistance to Group A herbicides. An integrated approach to weed management aimed at lowering the weed seed bank can make use of diverse techniques such as cultivation, stubble burning, in-crop competition using higher sowing rates and possibly row orientation. The weed seed bank can be reduced within the break phase by hay making, or green or brown manuring. Other techniques used effectively in WA on ryegrass and wild  radish have been narrow windrows and chaff carts. However there is limited information on the effectiveness of these tactics on barley grass in part because it is believed that most seed is shed well before harvest, limiting control. In 2015 the monitoring of farm paddock demonstrations in low rainfall farming systems to  assess control methods for grass weeds, mainly targeting barley grass, were undertaken by;
• Monitoring of narrow windrows in MAC paddocks N1 and N6W, and Bruce Heddle’s paddock CE42 (windrows and chaff dumps).
• Spray topping after oat and vetch hay (MAC paddock S4) using both crop competition (high seeding rate) followed by spray topping after the hay cut.

Key messages
  • Weed seeds were found in narrow windrows and chaff dumps, ryegrass was more prevalent than barley grass which is more prone to shedding seed early.
  • Burning reduced the viable ryegrass and self-sown cereal seed density by 85%, reducing the overall weed seed bank, but results for barley grass were lower at 38%.
  • Conditions (i.e. temperature and humidity) and timing of burn were shown to strongly influence the effectivenessof this cultural management tactic.
  • Burning windrows resulted in fewer weed seeds returning to the weed seed bank.
  • There is a cost associated with windrow harvesting due to lower harvesting height requiring reducing the harvest speed with larger throughput of straw.
  • A better understanding of burning and the weather conditions needed to sterilise barley grass seed is needed.
Lead research organisation SARDI Minnipa Agricultural Centre
Host research organisation Eyre Peninsula Agricultural Research Foundation
Trial funding source GRDC EPF00001
Related program Maintaining profitable farming systems with retained stubble
Acknowledgments

Thanks to Ben Fleet and Sam Kleeman for knowledge and help with establishing the weed germination trays, Sue Budarick for managing and scoring the trays during the year and Roanne Scholz and Rochelle Wheaton for helping set the trays up. Trial funded by GRDC Maintaining profitable farming systems with retained stubble - upper Eyre Peninsula (EPF00001) and EP Rail Levy.


Other trial partners EP Rail Levy
Download the trial report to view additional trial information

Method

Crop types Oilseed: Canola Weed: Barley Grass
Treatment type(s)
  • Stubble: Management
Trial type Demonstration
Trial design Unreplicated

Minnipa Agricultural Centre 2015 Canola

Sow date Not applicable
Harvest date Not applicable
Plot size Not specified
Plot replication Not specified

Minnipa Agricultural Centre 2015 Barley Grass

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Download the trial report to view additional method/treatment information

Download results

Trial results Table 1

# Treatment 1
Average barley grass weed density (plants/m2) Average self-sown cereal weed density (plants/m2) Average medic/other broadleaved weeds (plants/m2) Average rye grass weed density (plants/m2) Average canola weed density (plants/m2)
1 3. Inter row (before burning) 95.6 11.9 107.5 109.9 0
2 In row non burnt (straw removed from 5 m row - soil collected after burning) 38.2 262.8 160.1 265.2 2.4
3 1. In row burnt (in row soil collected after burning) 19.1 43 76.5 78.8 0
4 % reduction in seed bank by windrow burning 50 84 52 70 100

Average barley grass weed density plants/m2


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Average canola weed density plants/m2


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Average medic/other broadleaved weeds plants/m2


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Average rye grass weed density plants/m2


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Average self-sown cereal weed density plants/m2


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Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Minnipa Agricultural Centre, SA Red loam
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Minnipa Agricultural Centre, SA Rudosol
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 Minnipa Agricultural Centre SA
2015 321.8mm
2014 374.5mm
2013 309.1mm
2012 331.2mm
2011 372.1mm
2010 355.3mm
2009 367.4mm
2008 310.4mm
2007 330.8mm
2006 342.9mm
2005 316.5mm
2004 323.7mm
2003 305.0mm
2002 305.7mm
2001 303.3mm
2000 332.8mm
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

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Climate

Minnipa Agricultural Centre SA 2015


Observed climate information

Rainfall avg ann (mm) 325mm
Rainfall avg gsr (mm) 241mm
Rainfall trial total (mm) 333mm
Rainfall trial gsr (mm) 258mm

Derived climate information

Minnipa Agricultural Centre SA

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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.



Trial last modified: 14-01-2023 22:51pm AEST