A presentation from the WCCA 2011 conference in Birsbane.

1. Do livestock reduce crop yields in
conservation farming systems?
James Hunt, Tony Swan, John Kirkegaard, Paul Breust, Mark Peoples

2. Southern Australian mixed farming systems
• Sheep & wheat
• Sheep graze crop residues, spilt grain and vegetative crops
• Legume based pastures provide N and disease break for crops
• Will the full benefits of no-till and controlled traffic ever be
realised whilst sheep are trampling soil and removing cover?
• Very little contemporary evidence (Bell et al. 2011 Soil & Tillage
Research 113)
• First two years of GRDC project designed to test;
What impacts do sheep grazing on crops and stubbles
have on soil structure, water dynamics and crop yield?
Livestock & conservation farming

3. “Collective Inquiry”
Project structure
CSIRO Farmer Consultant Consultant
• Add photo of researchFarmlink
FarmerFarmlink committee Farmer Farmer
CSIRO
WUE & canopy management - Soil2Grain SW WA July 2010

4. Research site – Temora, southern NSW
• Peter, Lynne and Jason Coleman’s farm (6 km south of
Temora)
• Annual rainfall ~ 520 mm temperate pattern
• Red Chromosol with flat topography
• Lucerne pasture of 4 years in 2008
• No-till (300 mm row spacing), knife-points and press wheels
• Controlled traffic
Livestock & conservation farming

5. Spraying on tramlines (CT)
Livestock & conservation farming

6. Effects of stock on soil & crop
• Treatments
1. Nil graze, stubble retention
2. Nil graze, stubble burn
3. Stubble graze, stubble retention
4. Stubble graze, stubble burn
5. Winter graze, stubble graze, stubble retention
6. Winter graze, stubble graze, stubble burn
• Rotation
Phase 1: Lucerne 08 - wheat 09 - canola 10 - wheat 11
Phase 2: Lucerne 09 - wheat 10 - canola 11 - wheat 12
Livestock & conservation farming

7. Effects of stock on soil and crop
wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
• Treatments summer 2009/2010
1. Nil graze (5.4 t/ha stubble)
2. Stubble graze (0.8 t/ha stubble)
3. Winter & stubble graze (0.8 t/ha stubble)
Livestock & conservation farming

8. wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
5.4 t/ha 0.8 t/ha

9. Soil water accumulation summer 2009/2010
wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
• 310 mm of summer rain • 18 mm early Feb
• 43 mm late Nov/early Dec • 104 mm mid Feb
• 48 mm at Christmas • 82 mm early Mar
Plant available water 10-180 cm (mm)
Treatment 16 Dec 09 13 Jan 10 23 Feb 10 16 Mar 10
Nil graze 13 14 105 155
Stubble graze 14 14 77 110
Stubble & winter graze 15 16 66 99
LSD (P=0.05) NS NS 13 19
Livestock & conservation farming

10. Soil water 0-20 cm – no effect of stubble over summer
60
102 mm
Graze 0.8 t/ha stubble
82mm
Nil graze 5.4 t/ha stubble
50
Plant available water 0-20 cm (mm)
43 mm
40
43mm
30
18 mm
20
10
0
26-Nov 16-Dec 5-Jan 25-Jan 14-Feb 6-Mar 26-Mar
Date
Livestock & conservation farming

11. Soil water 16 March 2010
Soil water (mm/mm)
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40
0
20
40
Drained Upper Limit (mm/mm)
60
Soil water – Nil grazed
Depth (cm)
80
Soil water - Grazed
100
120
140
Stubble improved
water infiltration
160
180
Livestock & conservation farming

12. Infiltrometer measurements March and April 2010
wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
Treatment in 2009 Steady-state
infiltration rate
(mm/h)
Wheat stubble - Nil graze 36a
Wheat stubble - Stubble graze 20b
Wheat stubble - Winter & stubble graze 16b
Canola (little stubble cover) - Nil graze 11b
LSD (P=0.05) 11
Livestock & conservation farming

13. wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
• Canola Tawriffic TT sown over all treatments 15 April 2010
• Winter grazed prior to bud emergence
• 426 mm GSR
Livestock & conservation farming

14. Canola grain yield 2010
• No significant effect of grazing on canola grain yield
• Differences in PAW from summer 09/10 still present
Treatment Canola grain yield PAW at canola
(t/ha) maturity (mm)
Nil graze (5.4 t/ha wheat 4.1 116
stubble)
Stubble graze (0.8 t/ha 4.2 86
wheat stubble)
Stubble & winter graze (0.8 4.0 78
t/ha wheat stubble)
P-value 0.62 0.01
LSD (P=0.05) NS 25
Livestock & conservation farming

15. Effects of stock on soil and crop
• Treatments summer 2010/2011
1. Nil graze (8 t/ha stubble)
2. Stubble graze (4 t/ha stubble)
3. Winter & stubble graze (4 t/ha stubble)
wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
Livestock & conservation farming

18. Soil water 0-20 cm - summer fallow 2010-2011
Livestock & conservation farming

19. Plant available water & N at sowing 2011
wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
Mineral N (kg/ha) PAW (mm) 15
Grazing treatment 15 April 2011 April 2011
Nil graze (8 t/ha stubble) 93a 201a
Stubble graze (4 t/ha stubble) 126ab 183b
Winter and stubble graze (4 t/ha stubble) 199b 187b
P-value 0.001 0.011
LSD(P=0.05) 49 11
CV (%) 28 5.6
Livestock & conservation farming

20. wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
Canopy temperature
Grazing treatment (°C)
Nil graze (8 t/ha stubble) 21.8a
Stubble graze (4 t/ha stubble) 22.6b
Winter and stubble graze (4 t/ha stubble) 23.0b
P-value 0.005
LSD(P=0.05) 0.7
CV (%) 2.8

21. Acknowledgements
• CSIRO & FarmLink Research team – Tony Swan, Paul
Breust, James Hunt, John Kirkegaard, Mark Peoples
• FarmLink WUE steering committee - Jason Coleman, Peter
Coleman, Greg Condon (Grassroots Agronomy), Chris Duff
(Delta Agribusiness), Derek Ingold, James Ingrey, Geoffrey
Lane, John Pattison, Jamie Pursehouse (Landmark – Ariah
Park), Michael Sinclair, Rob Taylor, Craig Warren (Landmark -
Temora)
• NSW I&I – Col McMaster, Neil Fettell & Ian Menz,
• Lindsay Bell – CSIRO Toowoomba
• Seed provided by Hart Bros. Seeds & Pioneer
• Bayer CropScience - Sakura
Livestock & conservation farming

22. CSIRO Plant Industry
James Hunt
Research Scientist
Phone: 0428 636 391
Email: james.hunt@csiro.au
Web: www.pi.csiro.au/
Thank you
Contact Us
Phone: 1300 363 400 or +61 3 9545 2176
Email: Enquiries@csiro.au Web: www.csiro.au