Investigating double break (or stacked rotation) options

2018
CC BY 4.0

Research organisaton
Funding source

Trial details

Researcher(s) Nathan Craig
Brianna Hindle
Year(s) 2018
Contributor West Midlands Group
Trial location(s) Merredin, WA
Investigating double break (or stacked rotation) options locations
Aims

In Western Australia, break crop options are currently limited and there is a high proportion of wheat and barley grown in rotation. Cereal crops account for 60-70% of paddocks sown in any one year, with the remaining area sown to a range of crop and pasture types including canola, lupin, clover, volunteer pasture, or left as fallow. In addition, there is an interest in chickpea and lentil to add a high value legume to the crop rotation. The application of these break crops is dependent on the grain price per tonne and on the level of severity of biological constraints present that lead to a reduction in grain yield and which varies from paddock to paddock. The use of a single break crop in rotation has been shown to be an effective tool in managing both weed and diseases that affect wheat production to remove biological constraints to crop production and allow the sustained production of cereal crops. However, with a change in resistance status of many common weeds and diseases, and a change in soilborne pathogens, a single break crop applied to a cropping system that is largely based on cereals has limited effect in reducing the biological constraints, with the longevity of the break crop benefit being reduced. Recent studies into the break crop benefits for highly herbicide resistant weed populations has found that a break of at least two years was needed to prevent grass seed set and substantially reduce grass seedbank numbers. 

Considering the high percentage of cereal crops grown in Western Australia, there is the need to evaluate the use of double break crop sequences to improve wheat grain yield and profitability. In particular, the Eastern Wheatbelt region has very limited break crop options, and there is the need to investigate the better use of tools such as fallow periods to improve break crop outcomes.

Key messages

The success of break crops to increase wheat production in the Eastern Wheatbelt is dependent on firstly addressing any physical and chemical soil constraints to crop production and where the previous land use is a chemical fallow. In this situation, the grain yield of lupin, chickpea, lentil and field pea was 0.97-1.42 t/ha 0.67-1.1 t/ha, 0.3-0.97 t/ha, and 1.2 t/ha respectively in a below average season. The yield of wheat following legume break crops tended to be higher than either canola or wheat planted in the remaining paddock area. The profitability of double break-crop sequences was negative in many of the sequences evaluated in this study compared to a positive profit for continuous wheat. The profitability of double break-crop sequences can be improved by the inclusion of high value legumes as the second break-crop, but further work is required to lower the risk of growing these species of crops.The yield of wheat following legume break crops tended to be higher than either canola or wheat planted in the remaining paddock area. The profitability of double break-crop sequences was negative in many of the sequences evaluated in this study compared to a positive profit for continuous wheat. The profitability of double break-crop sequences can be improved by the inclusion of high value legumes as the second break-crop, but further work is required to lower the risk of growing these species of crops.

Lead research organisation West Midlands Group
Host research organisation N/A
Trial funding source GRDC WMG00003_A
Related program N/A
Acknowledgments

This project is a GRDC investment. Thank you to the Gillett, Harper, Even, Large, and Evans families for hosting trial sites for the lat three years. Thank you to the Corrigin Farm Improvement Group for managing the Corrigin demonstration site.


Other trial partners Corrigin Farm Improvement Group
Download the trial report to view additional trial information

Method

Crop type Wheat
Treatment type(s)
  • Crop: Type
Trial type Experimental
Trial design Replicated

Merredin 2018

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
Trial source data and summary not available
Check the trial report PDF for trial results.
Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Merredin, WA Not specified
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Merredin, WA Sodosol
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 Merredin WA
2018 276.3mm
2017 291.2mm
2016 320.5mm
2015 301.9mm
2014 283.4mm
2013 334.1mm
2012 309.2mm
2011 274.5mm
2010 250.3mm
2009 281.9mm
2008 272.0mm
2007 246.8mm
2006 306.6mm
2005 274.8mm
2004 292.2mm
2003 295.6mm
2002 238.8mm
2001 286.1mm
2000 311.7mm
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

Derived climate information

No observed climate data available for this trial.
Derived climate data is determined from trial site location and national weather sources.

Merredin WA

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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: 19-10-2019 11:43am AEST