Barley grass management in retained stubble systems - farm demonstrations

2015

Research organisatons
Funding source

Trial details

Researcher(s) Amanda Cook (SARDI)
Year(s) 2015
Contributor Eyre Peninsula Agricultural Research Foundation
Trial location(s) Site 4, 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 type Canola
Treatment type(s)
  • Stubble: Management
Trial type Demonstration
Trial design Unreplicated

Minnipa Agricultural Centre 2015

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

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
Site 4, Minnipa Agricultural Centre, SA Red loam
Derived trial site soil information
Australian Soil Classification Source
Trial site Soil order
Site 4, Minnipa Agricultural Centre, SA Rudosol
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

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Climate

Site 4, 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

Site 4, 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.




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Trial last modified: 04-06-2019 11:58am AEST