Amanda Cook (SARDI)
|Contributor||Eyre Peninsula Agricultural Research Foundation|
Site 4, Minnipa Agricultural Centre, SA
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.
|Lead research organisation||
SARDI Minnipa Agricultural Centre
|Host research organisation||
Eyre Peninsula Agricultural Research Foundation
|Trial funding source||GRDC EPF00001|
Maintaining profitable farming systems with retained stubble
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|
|Sow date||Not specified|
|Harvest date||Not specified|
|Plot size||Not specified|
|Plot replication||Not specified|
||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|
|Rainfall avg ann (mm)||325mm|
|Rainfall avg gsr (mm)||241mm|
|Rainfall trial total (mm)||333mm|
|Rainfall trial gsr (mm)||258mm|
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.