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