managing climatic extremes in the lower namoi region · david & peter ricardo • dryland...
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Australian Cotton Conference 2018
Managing climatic extremes in the Lower Namoi Region
By David Ricardo, 7th August 2018
Lower Namoi Region
Lower Namoi Region
Lower Namoi Map – Murray Darling Basin Authority https://www.mdba.gov.au/sites/default/files/archived/proposed/EWR-Lower-Namoi-River-in-channelflows.pdf
Walgett Climate
Walgett Annual Rainfall History since 1900
CliMate - variability table and historyhttps://climateapp.net.au/A03_HowsTheSeason
Floods
February 2012
March 2012
Droughts
Heat
2nd March 2017
Wind/Dust
23 September 2009
15 December 2015
David & Peter Ricardo
• Dryland Farming 9000 ha east of Walgett
• Grey vertosol soils store 250mm moisture
• Winter Crops - cereals, pulses, and canola
• Summer Crops - dryland cotton 2016, 2017
Cotton 2016
Cotton 2017
Changes to our cropping system
• Zero till / GPS / Tramlining • Broadacre scale - block management • Big machinery• Crop rotation• Fallow efficiency
Shelbourne Stripper
Stubble Trials
• Useful gains in soil water once groundcover > 100%
• Amount of soil water related to groundcover %
• Soil water in top 20cm is prone to evaporative losses
Rainfall Pattern during stubble trials (22 months)
The key question
Q: How do we increase our fallow efficiency in a variable climate?
The key question
Q: How do we increase our fallow efficiency in a variable climate?
A: Crop rotation with winter cereals and stripper fronts to increase stubble loads
More ground cover = more moisture
www.morvenvale.farmnet.com.au