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A presentation from the WCCA 2011 conference in Birsbane.
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Do livestock reduce crop yields in conservation farming systems?James Hunt, Tony Swan, John Kirkegaard, Paul Breust, Mark Peoples
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
WUE & canopy management - Soil2Grain SW WA July 2010
Project structure
• Add photo of research committeeCSIRO
CSIROFarmerFarmer
FarmerFarmerFarmlink
Farmlink Consultant Consultant
“Collective Inquiry”
Livestock & conservation farming
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 farmingSpraying on tramlines (CT)
Livestock & conservation farming
Effects of stock on soil & crop
• Treatments1. 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
• RotationPhase 1: Lucerne 08 - wheat 09 - canola 10 - wheat 11
Phase 2: Lucerne 09 - wheat 10 - canola 11 - wheat 12
Livestock & conservation farming
Effects of stock on soil and crop
wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
• Treatments summer 2009/20101. Nil graze (5.4 t/ha stubble)
2. Stubble graze (0.8 t/ha stubble)
3. Winter & stubble graze (0.8 t/ha stubble)
0.8 t/ha5.4 t/ha
wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
Soil water accumulation summer 2009/2010
• 310 mm of summer rain• 43 mm late Nov/early Dec• 48 mm at Christmas
• 18 mm early Feb• 104 mm mid Feb• 82 mm early Mar
Livestock & conservation farming
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
wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
Livestock & conservation farming
Soil water 0-20 cm – no effect of stubble over summer
0
10
20
30
40
50
60
26-Nov 16-Dec 5-Jan 25-Jan 14-Feb 6-Mar 26-Mar
Date
Pla
nt
avai
lab
le w
ater
0-2
0 cm
(m
m)
Graze 0.8 t/ha stubble
Nil graze 5.4 t/ha stubble
43mm
43 mm
18 mm
102 mm
82mm
Livestock & conservation farming
Soil water 16 March 2010
0
20
40
60
80
100
120
140
160
180
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40
Soil water (mm/mm)D
epth
(cm
)
Drained Upper Limit (mm/mm)
Soil water – Nil grazedSoil water - Grazed
Stubble improvedwater infiltration
Livestock & conservation farming
Infiltrometer measurements March and April 2010
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
wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
Livestock & conservation farming
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
• No significant effect of grazing on canola grain yield• Differences in PAW from summer 09/10 still present
Livestock & conservation farming
Canola grain yield 2010
Treatment Canola grain yield (t/ha)
PAW at canola maturity (mm)
Nil graze (5.4 t/ha wheat stubble)
4.1 116
Stubble graze (0.8 t/ha wheat stubble)
4.2 86
Stubble & winter graze (0.8 t/ha wheat stubble)
4.0 78
P-valueLSD (P=0.05)
0.62NS
0.0125
Livestock & conservation farming
Effects of stock on soil and crop
• Treatments summer 2010/20111. 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
Soil water 0-20 cm - summer fallow 2010-2011
Livestock & conservation farming
Plant available water & N at sowing 2011
Grazing treatmentMineral N (kg/ha)
15 April 2011PAW (mm) 15
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
wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
Grazing treatmentCanopy temperature
(°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 0.005LSD(P=0.05) 0.7
CV (%) 2.8
wheat 09 – summer fallow - canola 10 – summer fallow – wheat 11
Livestock & conservation farming
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
Thank you
CSIRO Plant IndustryJames HuntResearch Scientist
Phone: 0428 636 391Email: [email protected]: www.pi.csiro.au/
Contact UsPhone: 1300 363 400 or +61 3 9545 2176Email: [email protected] Web: www.csiro.au